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The two graphs below show the population in two countries and fertility rates.
Final Lab I emailed these photos to you. Please look for them.
Tuesday, May 13, 2008
lab 1 & 2 pictures
Pregnancy Lab Pictures
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The two graphs below show the population in two countries and fertility rates.
Final Lab
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The two graphs below show the population in two countries and fertility rates.
Final Lab
lab 1 & 2, Final Lab & Ethical Essay
Lab 1 About Pregnancy
I could not get the pictures to load so I am going to email them to you.
Pic 1
Trophoblast cells continue to engulf and destroy cells of the uterine lining creating blood pools and stimulating new capillaries to grow - beginning the growth of the placenta.
The blastocyst inner cell mass differentiates into two layers:
EPIBLAST The top layer of cells (dark blue) which will become the embryo and amniotic cavity.
HYPOBLAST Lower layer of cells (yellow) which become the yolk sac.Ectopic pregnancies - implantation sites not in the uterus - can occur at this time and may continue up to 16 weeks unnoticed. Quick diagnosis can pharmacologically treat without surgery preserving the site of the pregnancy.
Pic 2
Esophagus Forming stage 16
SIZE: 5.0 - 7.0 mm31- 35 days post-ovulationn
Head and NeckThe brain and head grow rapidly. The mandibular and hyoid arches are noticeable. Ridges demarcate the three sections of the brain (midbrain, forebrain and hindbrain). The spinal cord wall at this stage contains three zones: the ventricular, the mantle and the marginal. The ventricular zone will form neurons, glial cells and ependymal cells, the intermediate mantle will form neuron clusters and the marginal zone will contain processes of neurons. Adenohypophyseal pouch, which will develop into the anterior pituitary, is defined.Lens vesicle opens to the surface and is nestled within the otptic cup. Otic vesicle increases its size by approximately one-fourth and its endolymphatic appendage is more defined. Nasal plate can be detected by thickened ectoderm.ThoraxEsophagus, the tube through which food is swallowed, forms from a groove of tissue that separates from the trachea, which is also visible.Semilunar valves begin to form in the heart. Four major subdivisions of the heart (the trabeculated left and right ventricles, the conus cords and the truncus arteriosus) are clearly defined. Two sprouts, a ventral one from the aortic sac and a dorsal one from the aorta, form the pulmonary (sixth aortic) arch.Right and left lung sacs lie on either side of the esophagus.Abdomen and Pelvic RegionsUreteric bud appear. Metanephros, which will eventually form the permanent kidney, is developing.LimbsUpper limbs elongate into cylindrically-shaped buds, tapering at tip to eventually form hand plate. Nerve distribution process, innervation, begins in the upper limbs .
Pic 3
Hindbrain Begins to Develop
SIZE: 9.0 - 11.0 mmTIME PERIOD: 37 - 42 days post-ovulation
I think that the first few weeks are extremely important because if one thing is not right then it effects the rest of the formation later on. From the cell division to the development of limbs, heart and lungs.
Head and NeckBrain is well marked by its cerebral hemispheres. The hindbrain, which is responsible for heart regulation, breathing and muscle movements, begins to develop.Future lower jaw, the first part of face to be established, is now visible while future upper jaw is present, but not demarcated.Mesenchymal cells originating in the primitive streak, the neural crest and the prechordal plate, continue to form the skull and the face.External retina pigment is visible and the lens pit has grown into a D shape. Nasal pits are still two separate plates, but they rotate to face ventrally as head widens.
ThoraxPrimary cardiac tube separates into aortic and pulmonary channels and the ventricular pouches deepen and enlarge, forming a common wall with their myocardial shells. Mammary gland tissue begins to mature.Abdomen and Pelvic RegionsThe mesentery, which attaches the intestines to the rear abdominal wall, holds them in position and supplies them with blood, nerves and lymphatics, is now clearly defined. Ureter, the tube that will convey urine from the kidney to the bladder, continues to lengthen. Proliferation of the coelomic epithelium indicates the gonadal primordium.LimbsHand region of upper limb bud differentiates further to form a central carpal part and a digital plate. The thigh (rostrolateral part), leg (the caudomedial part) and foot areas can be distinguished in the lower limb buds.
Pic 4
Spontaneous Movement Begins. ••••• Stage 20 first trimester
SIZE: 15.0 - 20.0 mm51 - 53 days post-ovulation
I think this stage is important because movement spontaneously happening and the elbows bend and extend. Joints are forming and the anal membrane is perforated at this time.
Head and NeckBrain is connected to tiny muscles and nerves and enables the embryo to make spontaneous movements. The scalp plexus is now present. Nasal openings and the tip of the nose are fully formed.PelvisAnal membrane is perforated. Urogenital membranes differentiate in male and female embryos. Testes or ovaries are distinguishable.LimbsThe upper limbs become longer and continue to bend at the elbows and extend forward. Skin on the foot plate folds down between the future toes, each distinguishable from the other.nd get stronger.
Pic 5
Bone marrow starts making blood cells 20 weeks
The crown-to-rump length 5.6 to 6.4 inches (14 to 16cm).
I think this stage is important because the heart beat gets stronger and bloods cells are being formed in the blood marrow.
Head and NeckExtremely rapid brain growth begins lasting until five years after birth. Eyebrows and scalp hair become more visible and fetus blinks more often. Lanugo hair covers body completely, although concentrated around head, neck and face.ThoraxHeart beat grows stronger.PelvisTestes of male fetuses begin descending from the pelvis into the scrotum.LimbsLegs approach final length and proportion relative to body. Arms and legs move with more force, as muscles strengthen. Skeleton hardens. Hand strength improves. Although the placenta provides nearly all fetal nourishment, fetus will begin to absorb small amounts of sugar from swallowed amniotic fluid. By 21 weeks, fetal bone marrow starts making blood cells — previously done by the liver and spleen.
Pic 6
Possible hearing 22 weeks
SIZE: weight about 12.25 ounces (350g). Crown-to-rump length at this time is about 7.6 inches (19cm).
I think this stage of development is important because the fetus is able to recognize sounds, breathing, and digestion. It is a time of bonding with the mother.
Head and NeckBones of the ear - hammer, anvil and stirrup - harden, making sound conduction possible. Fetus recognizes maternal sounds such as breathing, heartbeat, voice, and digestion.Thorax Respiratory system continues to develop; lungs are not yet able to transfer oxygen to bloodstream and release carbon dioxide by exhaling.AbdomenBones, muscles and organs are growing steadily.SkinBlood vessels, bones and organs are visible underneath a thin layer of wrinkled, translucent, pink skin.
Pic 7
Brain activity 24 weeks
weight about about 1.2 pounds (540g). Its crown-to-rump length is about 8.4 inches (21cm). Mother's Size:
I think this important because the spine is continuing to form during this time as well as joints and liagments… the foundation for growth and movement.
Head and NeckFetal brain waves begin to activate auditory and visual systems, both mouth and lips show more sensitivity. Eyes respond to light, while ears respond to sounds originating outside uterus. Permanent teeth buds appear high in gums. Nostrils begin to open. Reflex movements improve.Thorax Blood vessels start to develop in lungs to prepare fetus for life outside the uterus. These bloods vessels will eventually exchange oxygen and circulate it to tissues. Air sacs, alveoli, have developed in lungs and begin to produce surfactant, a substance that keeps the lung tissue from sticking to itself. However, lungs are not completely ready to breath air.Limbs Finger and toe nails continue to grow.SpineThe spine consists of 33 rings, 150 joints and 1,000 ligaments, supporting fetal body weight as it develops and strengthens.
Pic 8
Brain Surface Convolutions Begin. ••••• 28 weeks
Fetal size: weight almost 2.4 pounds (1.1kg). Crown-to-rump length is close to 10 inches (25cm). Total length is 15.75 inches (35cm).
I think this is important because the breathing abd body temperatures are regulated by the brain. I think this is vital to surviving after birth.
Head and NeckFetal brain's surface appears wrinkled. These convolutions provide more surface area and maximize brain cells. Rhythmic beathing and body temperature are now controlled by the brain.Lanugo hair has disappeared almost completely, except on back and shoulders. Head hair is present.LimbsProduction of red blood cells is entirely tasken over by the bone marrow.AbdomenFetal body is two to three percent body fat.SkinSkin begins to smoothen as fat deposits accumulate underneath. The fat insulates and is an energy source.
Pic 9
Rapid brain growth; head size increases. ••••• 30 weeksFetal size:
weight about 3 pounds (1.35kg). Its crown-to-rump length is a little over 10.8 inches (27cm), and total length is 17 inches (38cm).I think this is important because the growth of the brain is vital to the inner works of the body. Any abnormalities could possibly lead to disruption in homeostasis.
Head and NeckRapid brain growth continues and head size increases as the growing brain pushes the skull outward creating more surface convolutions. This quick growth increases the number of interconnections between individual nerve cells. The iris is colored and the pupil reflexes responding to light. Head hair grows thicker.
LimbsToenails are fully formed. Because of the lack of space in the uterus, the legs are drawn up in what is known as the fetal position.
Pic 10
Fetus Begins To Develop Immune System. ••••• 32 weeksFetal size:
weight almost 4 pounds (1.8kg). Crown-to-rump length is over 11.6 inches (29cm), and total length is 18.9 inches (42cm).II think this is important because it is when the development begins for the immune system which is necessary for the baby when born to aid them in fighting infections and diseases that might arise.Head and NeckEyes open during alert times and close during sleep. Eye color is usually blue, regardless of the permanent color as pigmentation is not fully developed. Final formation of eye pigmentation requires exposure to light and usually happens a few weeks after birth. The iris is colored and the pupil reflexes responding to light. Head hair grows thicker.AbdomenFetus begins to develop its own immune system. LimbsFingernails reach over finger tips and fetus can scratch itself.SkinWhite fat builds up underneath skin, making fetus appear lighter in color.
Pic 11
Abdomen is large and round as fetal liver is producing blood cells. •••••
38 weeks Fetal size:
weight a little more than 6.8 pounds (3.1kg). Crown-to-rump length hasn’t changed much; it’s still about 14 inches (35cm). Total length is around 21 inches (47cm).Mother's size: From the pubic symphysis to the top of the uterus, measures approximately 14.4 to 15.2 inches (36 to 38cm). From your bellybutton to the top of your uterus is about 6.4 to 7.2 inches (16 to 18cm).
HeadSkull is not fully solid as the five bony plates, known as fontanels (little fountains), are still separate and can be pushed together. Birth may mold and elongate the fetal head, a safety precaution to reduce the skull's diameter for an easier birth, without damaging the fetal brain. After delivery, the baby's head returns to a rounded shape. Eyes have no tear ducts yet, they appear a few weeks after birth. ThoraxChest is more prominent. Lungs begin to increase production of surfactant to keep alveoli open.AbdomenFetal abdomen is large and round mainly due to the liver which is producing red blood cells.SkinLast of vernix usually disappears, but may remain until birth. Skin becomes thicker and paler (white or bluish pink) and each day the fetus gains 1/2 ounce (14 g) of fat.
Pic 12
Fetus now considered full term. ••••• 40 weeksFetal size: weight about 7.5 pounds (3.4kg). Crown-to-rump length about 14.8 to 15.2 inches (37 to 38cm). Total length is 21.5 inches (48cm)Mother's size: From the pubic symphysis to the top of the uterus, measures approximately 14.4 to 16 inches (36 to 40cm). From your bellybutton to the top of your uterus is 6.4 to 8 inches (16 to 20cm).
AbdomenFifteen percent of body is fat, eighty percent of which is underneath the skin, the other twenty percent surrounds the organs. LimbsAt the time of birth, the baby has a total of 300 bones. Some bones will fuse together later, which is why an adult has only 206 bones.AbdomenFetal abdomen is large and round mainly due to the liver which is producing red blood cells.Nervous SystemA fetus can display more than seventy different reflex system behaviors which are automatic and unlearned behaviors necessary for survival.
Final lab
Dog Gizmo: Canis lupus familiaris: symbiotic;they provide companionship
We have been co existing with this type of animal for quite some time.
Dog kisses : Canis lupus familiaris: mutuality… unless youa re tlking about wolves or coyotes then it is predator/ prey. Dogs do contain the virus that may cause strep throat which in turn may cause heart conditions and high fevers. Before the development of antibiotics it was not possible to fight off serious implications that might have taken place if contracting the virus.
Many people I have seen allow their dog to kiss them on the lips and lick them all over so co-existing has been going on for quite some time.
Petting the guinea pig: Cavia porcellus (in the wild) they help in keeping vegitation done to a minium in the areas in which that inhabit. We have co-existed with these little guys for quite some time. They are in the wild and have been domesticated and considered to be a very good first pet for young kids.
Holding a Lizard: Draco volans: symbiotic: Lizards are native to certain areas of the world from the wetlands to the deserts and haven’t been a problem for us yet. Although they do have the possibility to contain what is called salmanilla.
Bird feathers : Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Aves
Bird and the bees have been around for quite some time and co-existing has been moving along. Although recently and presently we are experiencing problems with avian flu. This has taken its toll on many people hospitalizing and even threatening the lives of those who come in contact with it.
Pairie dogs playing in dirt: Cynomys ludovicianus (black-tailed prairie dog)
These little guys were digging holes in a vacant area in Colorado and I noticed that children had even built a fort close to the area where these little guys were taking up residency.
Holding my cat: Felidae: symbiotic
Cats domesticated and farrow have been around for hundreds of years. We have co-existed with them and adapted threw the years. But I have heard of cat scratch fever as well as the little box changing and aromas that are inhaled are not good for pregnant people to be around.
Feeding a Tiger: Panthera tigris : predator/prey
We are co-existing with these great creatures but actually it is not suggested that we jump in their and play with them. When I fed this guy I had to put on latex gloves and wash my hands with sanitizer. So I am not sure if I actually had to wear these gloves to protect me from getting something from them or to prevent me from giving something to the tiger!
Feeding a goldfish: Carassius auratus: symbiotic
The goldfish is domesticated and considered to be a great pet. Algae does grow in the side of the aquarium and the water actually has a tendency to smell. I would not suggest drinking that as a cocktail.
Mistletoe growing on tree: Arceuthobium campylopodum: parasitic
Mistletoe is not harmful to us but it does pose a threat to the trees it preys upon. If the mistletoe is not taken under control then it could lead to the overall destruction to the tree it is living off of.
Dead heading flowering bushes: Magnoliophyta:mutualism: it helps in prolonging the blooming fo these flowers. We do co-exist with many plants and some of which that if ingested may cause illness, death, or joy.
Biting finger nail: Commensal: there are not harmful germs under the nails but after a day in the experiences of life there could be colds, flu, and harmful bacteria that could be found under the nails.
Hummingbird on bush: Trochilidae: mutualism: Hummingbirds are great for our environment they help in spreading pollen from plant to plant. Therefore leading to mreo and more hybrid or populating plants.
Lab 2 Population
1. What was your high fertility rate country and what was its fertility rate?The high fertility rate country I chose was the United States. The fertility rate was 2 children. Benin was a small country but a high rise in population. Fertility rate of 6.90 and the life expectancy was 50.9
2. What was your low fertility rate country and what was its fertility rate?Ireland was the country I picked and the fertility rate was 2 children.
3. The initial demographic "shape" of your high fertility rate country should have been a pyramid, with high population in young age groups. Explain why high fertility rate results in a high percentage of young people in the population. How does this affect future population growth? Younger people being born in vast numbers can throw off the number of people that would be able to marry. With people living longer. There leaves a gap. Many kids being born. People living longer might pose a problem as well. Young people having babies and “flooding the market” so to speak.4. Your low fertility rate country might have had a more oval-shaped curve with high population in middle age groups. This is especially exaggerated if the fertility rate is below 2.00. Explain why low fertility rate leads to lots of middle-aged people. Lots of middle aged people are vastly populated countries with low fertility rates because there are not as many people being born and the people populating the region of aging. This could be associated with a larger fertility rate during their generation.5. Write ten adjectives or descriptive phrases for what you might expect life, people's attitudes, conditions on the streets, etc. will be like in each of those situations. Imagine a situation with lots of middle-aged and older people in the population and write ten quick "brain-storm" descriptors for you think it would be like (Prescott, Arizona?). Then do the same for a situation with lots of children in the population.
Middle aged and older people adjectives
Traditional, educated, involved, mellow, stable, crafty, dog lovers, caring, loving, tired, old-fashioned, and ethical
Younger populated areas:
Reckless, violence, death, rowdy, athletic, energetic, school oriented, friendly, laughter, smiles, and carefree
Ethical Essay
When thinking about who should reproduce and who should not it is a question of personal in nature. It is all a matter of opinion that can not just be decided by the government. In China, they decided that there should be a limit to how many children each family could actually have. This not only aided in reducing the amount of energy used and strain on the country but now the country is in much better shape. Although I understand why it was done. If you are in a sinking ship do you stay on board or begin to identify the problem and fix it? With China they decided to fix the problem and have been reaping the benefits of such restrictions. We live in a society of freedom of speech and it was often thought by Americans that the restrictions placed on people as to how many children they may be able or not be able to produce would be a violation. But if you look at the broader picture population restrictions it is a means to an ends. If the country is struggling to make it work and provide for the people populating it then something needs to be done. This is what is happening in many third world countries and it is not getting them any further ahead of the poverty, sickness, and overwhelming incidents of birth defects and in Africa’s case the out of control epidemic of the AIDS virus. Maybe population regulations or sterilization would be beneficial to those countries. I am not sure if denying monies to those countries would be of assistance if anything it would lead to starvation and absence of medical availabilities would not benefit them in anyway unless death is the answer. We also need to look at our own environment. We are losing farming land due to land developments for subdivisions. We are having water shortages and restrictions for people due to usage and drought reasons. We are one of the largest polluting driven countries in the world and we are all, throughout the world, contributing to the depletion of the rainforest and the ozone layer. We have to look out for our future. Many times we just live in the now but we need to think of our children and the future that they might have. Population restrictions might be the necessary step that is needed in order to get the out of control population growth throughout the world under control. I don’t think that it needs to come down to deciding who is capable of raising a child. Or it needs to go into the background of the person as to whether or not this person should procreate but instead maybe restrictions on the amount of children a person can have might be a consideration. I mean goodness we have some people who have 10 and 12 children. This might have been necessary in the times of ranches and needing the helping hands to aid in the maintenance of the property. In third world countries sterilization has often been brought to the for front as a way of reducing population growth but it is a controversial idea. In talking about population reduction maybe instead of the families benefiting in the number of children they have an alternative to that might be offering stimulus packages for those people who only have 2 children or less. Not making it a requirement but instead an incentive because we are helping the environment. I mean people receive rebates for using solar power on their homes why not extend those to families that are helping to reduce the population growth.
Self Evaluation
1. What were the three aspects of the assignments I've submitted that I am most proud of?
I am proud of my ethical essay, compendium reviews and I enjoyed reading the web links.
2. What two aspects of my submitted assignments do I believe could have used some improvement? I have spend endless hours trying to figure out what in the world is going on with downloading pictures. So I am not happy with not having that on here. I think I could have done better on the final lab with more examples.
3. What do I believe my overall grade should be for this unit?
I think I should get a B because I don't have my pictures up. I am going to keep on trying so I am thinking maybe an A for effort.
4. How could I perform better in the next unit?
By not waiting until the last minute to post my posts. I was so excited about having teh work completed and to be done with the course and that quickly turned to aggrevation in an instant because it was not going as planned.
At what moment during this unit did you feel most engaged with the course?
I loved the chapters on evolution. I think that is very interesting. Fossils and foot steps in teh past always intrigue me.
At what moment unit did you feel most distanced from the course?
I felt like that when I was learning about meiosis and mitosis.
What action that anyone (teacher or student) took during this unit that find most affirming and helpful?
I liked the way the teacher was just an email away. Although... I felt frustrated because I could have turned in teh information if I had been able to just take it over to him.
What action that anyone (teacher or student) took during this unit did you find most puzzling or confusing? nothing.
What about this unit surprised you the most? (This could be something about your own reactions to the course, something that someone did, or anything else that occurs to you.)
I think this unit made me really stop and reflect and think about about the past and where we might have come from and the future where is the world going to be in 40 years! VERY INTERESTING!
I could not get the pictures to load so I am going to email them to you.
Pic 1
Trophoblast cells continue to engulf and destroy cells of the uterine lining creating blood pools and stimulating new capillaries to grow - beginning the growth of the placenta.
The blastocyst inner cell mass differentiates into two layers:
EPIBLAST The top layer of cells (dark blue) which will become the embryo and amniotic cavity.
HYPOBLAST Lower layer of cells (yellow) which become the yolk sac.Ectopic pregnancies - implantation sites not in the uterus - can occur at this time and may continue up to 16 weeks unnoticed. Quick diagnosis can pharmacologically treat without surgery preserving the site of the pregnancy.
Pic 2
Esophagus Forming stage 16
SIZE: 5.0 - 7.0 mm31- 35 days post-ovulationn
Head and NeckThe brain and head grow rapidly. The mandibular and hyoid arches are noticeable. Ridges demarcate the three sections of the brain (midbrain, forebrain and hindbrain). The spinal cord wall at this stage contains three zones: the ventricular, the mantle and the marginal. The ventricular zone will form neurons, glial cells and ependymal cells, the intermediate mantle will form neuron clusters and the marginal zone will contain processes of neurons. Adenohypophyseal pouch, which will develop into the anterior pituitary, is defined.Lens vesicle opens to the surface and is nestled within the otptic cup. Otic vesicle increases its size by approximately one-fourth and its endolymphatic appendage is more defined. Nasal plate can be detected by thickened ectoderm.ThoraxEsophagus, the tube through which food is swallowed, forms from a groove of tissue that separates from the trachea, which is also visible.Semilunar valves begin to form in the heart. Four major subdivisions of the heart (the trabeculated left and right ventricles, the conus cords and the truncus arteriosus) are clearly defined. Two sprouts, a ventral one from the aortic sac and a dorsal one from the aorta, form the pulmonary (sixth aortic) arch.Right and left lung sacs lie on either side of the esophagus.Abdomen and Pelvic RegionsUreteric bud appear. Metanephros, which will eventually form the permanent kidney, is developing.LimbsUpper limbs elongate into cylindrically-shaped buds, tapering at tip to eventually form hand plate. Nerve distribution process, innervation, begins in the upper limbs .
Pic 3
Hindbrain Begins to Develop
SIZE: 9.0 - 11.0 mmTIME PERIOD: 37 - 42 days post-ovulation
I think that the first few weeks are extremely important because if one thing is not right then it effects the rest of the formation later on. From the cell division to the development of limbs, heart and lungs.
Head and NeckBrain is well marked by its cerebral hemispheres. The hindbrain, which is responsible for heart regulation, breathing and muscle movements, begins to develop.Future lower jaw, the first part of face to be established, is now visible while future upper jaw is present, but not demarcated.Mesenchymal cells originating in the primitive streak, the neural crest and the prechordal plate, continue to form the skull and the face.External retina pigment is visible and the lens pit has grown into a D shape. Nasal pits are still two separate plates, but they rotate to face ventrally as head widens.
ThoraxPrimary cardiac tube separates into aortic and pulmonary channels and the ventricular pouches deepen and enlarge, forming a common wall with their myocardial shells. Mammary gland tissue begins to mature.Abdomen and Pelvic RegionsThe mesentery, which attaches the intestines to the rear abdominal wall, holds them in position and supplies them with blood, nerves and lymphatics, is now clearly defined. Ureter, the tube that will convey urine from the kidney to the bladder, continues to lengthen. Proliferation of the coelomic epithelium indicates the gonadal primordium.LimbsHand region of upper limb bud differentiates further to form a central carpal part and a digital plate. The thigh (rostrolateral part), leg (the caudomedial part) and foot areas can be distinguished in the lower limb buds.
Pic 4
Spontaneous Movement Begins. ••••• Stage 20 first trimester
SIZE: 15.0 - 20.0 mm51 - 53 days post-ovulation
I think this stage is important because movement spontaneously happening and the elbows bend and extend. Joints are forming and the anal membrane is perforated at this time.
Head and NeckBrain is connected to tiny muscles and nerves and enables the embryo to make spontaneous movements. The scalp plexus is now present. Nasal openings and the tip of the nose are fully formed.PelvisAnal membrane is perforated. Urogenital membranes differentiate in male and female embryos. Testes or ovaries are distinguishable.LimbsThe upper limbs become longer and continue to bend at the elbows and extend forward. Skin on the foot plate folds down between the future toes, each distinguishable from the other.nd get stronger.
Pic 5
Bone marrow starts making blood cells 20 weeks
The crown-to-rump length 5.6 to 6.4 inches (14 to 16cm).
I think this stage is important because the heart beat gets stronger and bloods cells are being formed in the blood marrow.
Head and NeckExtremely rapid brain growth begins lasting until five years after birth. Eyebrows and scalp hair become more visible and fetus blinks more often. Lanugo hair covers body completely, although concentrated around head, neck and face.ThoraxHeart beat grows stronger.PelvisTestes of male fetuses begin descending from the pelvis into the scrotum.LimbsLegs approach final length and proportion relative to body. Arms and legs move with more force, as muscles strengthen. Skeleton hardens. Hand strength improves. Although the placenta provides nearly all fetal nourishment, fetus will begin to absorb small amounts of sugar from swallowed amniotic fluid. By 21 weeks, fetal bone marrow starts making blood cells — previously done by the liver and spleen.
Pic 6
Possible hearing 22 weeks
SIZE: weight about 12.25 ounces (350g). Crown-to-rump length at this time is about 7.6 inches (19cm).
I think this stage of development is important because the fetus is able to recognize sounds, breathing, and digestion. It is a time of bonding with the mother.
Head and NeckBones of the ear - hammer, anvil and stirrup - harden, making sound conduction possible. Fetus recognizes maternal sounds such as breathing, heartbeat, voice, and digestion.Thorax Respiratory system continues to develop; lungs are not yet able to transfer oxygen to bloodstream and release carbon dioxide by exhaling.AbdomenBones, muscles and organs are growing steadily.SkinBlood vessels, bones and organs are visible underneath a thin layer of wrinkled, translucent, pink skin.
Pic 7
Brain activity 24 weeks
weight about about 1.2 pounds (540g). Its crown-to-rump length is about 8.4 inches (21cm). Mother's Size:
I think this important because the spine is continuing to form during this time as well as joints and liagments… the foundation for growth and movement.
Head and NeckFetal brain waves begin to activate auditory and visual systems, both mouth and lips show more sensitivity. Eyes respond to light, while ears respond to sounds originating outside uterus. Permanent teeth buds appear high in gums. Nostrils begin to open. Reflex movements improve.Thorax Blood vessels start to develop in lungs to prepare fetus for life outside the uterus. These bloods vessels will eventually exchange oxygen and circulate it to tissues. Air sacs, alveoli, have developed in lungs and begin to produce surfactant, a substance that keeps the lung tissue from sticking to itself. However, lungs are not completely ready to breath air.Limbs Finger and toe nails continue to grow.SpineThe spine consists of 33 rings, 150 joints and 1,000 ligaments, supporting fetal body weight as it develops and strengthens.
Pic 8
Brain Surface Convolutions Begin. ••••• 28 weeks
Fetal size: weight almost 2.4 pounds (1.1kg). Crown-to-rump length is close to 10 inches (25cm). Total length is 15.75 inches (35cm).
I think this is important because the breathing abd body temperatures are regulated by the brain. I think this is vital to surviving after birth.
Head and NeckFetal brain's surface appears wrinkled. These convolutions provide more surface area and maximize brain cells. Rhythmic beathing and body temperature are now controlled by the brain.Lanugo hair has disappeared almost completely, except on back and shoulders. Head hair is present.LimbsProduction of red blood cells is entirely tasken over by the bone marrow.AbdomenFetal body is two to three percent body fat.SkinSkin begins to smoothen as fat deposits accumulate underneath. The fat insulates and is an energy source.
Pic 9
Rapid brain growth; head size increases. ••••• 30 weeksFetal size:
weight about 3 pounds (1.35kg). Its crown-to-rump length is a little over 10.8 inches (27cm), and total length is 17 inches (38cm).I think this is important because the growth of the brain is vital to the inner works of the body. Any abnormalities could possibly lead to disruption in homeostasis.
Head and NeckRapid brain growth continues and head size increases as the growing brain pushes the skull outward creating more surface convolutions. This quick growth increases the number of interconnections between individual nerve cells. The iris is colored and the pupil reflexes responding to light. Head hair grows thicker.
LimbsToenails are fully formed. Because of the lack of space in the uterus, the legs are drawn up in what is known as the fetal position.
Pic 10
Fetus Begins To Develop Immune System. ••••• 32 weeksFetal size:
weight almost 4 pounds (1.8kg). Crown-to-rump length is over 11.6 inches (29cm), and total length is 18.9 inches (42cm).II think this is important because it is when the development begins for the immune system which is necessary for the baby when born to aid them in fighting infections and diseases that might arise.Head and NeckEyes open during alert times and close during sleep. Eye color is usually blue, regardless of the permanent color as pigmentation is not fully developed. Final formation of eye pigmentation requires exposure to light and usually happens a few weeks after birth. The iris is colored and the pupil reflexes responding to light. Head hair grows thicker.AbdomenFetus begins to develop its own immune system. LimbsFingernails reach over finger tips and fetus can scratch itself.SkinWhite fat builds up underneath skin, making fetus appear lighter in color.
Pic 11
Abdomen is large and round as fetal liver is producing blood cells. •••••
38 weeks Fetal size:
weight a little more than 6.8 pounds (3.1kg). Crown-to-rump length hasn’t changed much; it’s still about 14 inches (35cm). Total length is around 21 inches (47cm).Mother's size: From the pubic symphysis to the top of the uterus, measures approximately 14.4 to 15.2 inches (36 to 38cm). From your bellybutton to the top of your uterus is about 6.4 to 7.2 inches (16 to 18cm).
HeadSkull is not fully solid as the five bony plates, known as fontanels (little fountains), are still separate and can be pushed together. Birth may mold and elongate the fetal head, a safety precaution to reduce the skull's diameter for an easier birth, without damaging the fetal brain. After delivery, the baby's head returns to a rounded shape. Eyes have no tear ducts yet, they appear a few weeks after birth. ThoraxChest is more prominent. Lungs begin to increase production of surfactant to keep alveoli open.AbdomenFetal abdomen is large and round mainly due to the liver which is producing red blood cells.SkinLast of vernix usually disappears, but may remain until birth. Skin becomes thicker and paler (white or bluish pink) and each day the fetus gains 1/2 ounce (14 g) of fat.
Pic 12
Fetus now considered full term. ••••• 40 weeksFetal size: weight about 7.5 pounds (3.4kg). Crown-to-rump length about 14.8 to 15.2 inches (37 to 38cm). Total length is 21.5 inches (48cm)Mother's size: From the pubic symphysis to the top of the uterus, measures approximately 14.4 to 16 inches (36 to 40cm). From your bellybutton to the top of your uterus is 6.4 to 8 inches (16 to 20cm).
AbdomenFifteen percent of body is fat, eighty percent of which is underneath the skin, the other twenty percent surrounds the organs. LimbsAt the time of birth, the baby has a total of 300 bones. Some bones will fuse together later, which is why an adult has only 206 bones.AbdomenFetal abdomen is large and round mainly due to the liver which is producing red blood cells.Nervous SystemA fetus can display more than seventy different reflex system behaviors which are automatic and unlearned behaviors necessary for survival.
Final lab
Dog Gizmo: Canis lupus familiaris: symbiotic;they provide companionship
We have been co existing with this type of animal for quite some time.
Dog kisses : Canis lupus familiaris: mutuality… unless youa re tlking about wolves or coyotes then it is predator/ prey. Dogs do contain the virus that may cause strep throat which in turn may cause heart conditions and high fevers. Before the development of antibiotics it was not possible to fight off serious implications that might have taken place if contracting the virus.
Many people I have seen allow their dog to kiss them on the lips and lick them all over so co-existing has been going on for quite some time.
Petting the guinea pig: Cavia porcellus (in the wild) they help in keeping vegitation done to a minium in the areas in which that inhabit. We have co-existed with these little guys for quite some time. They are in the wild and have been domesticated and considered to be a very good first pet for young kids.
Holding a Lizard: Draco volans: symbiotic: Lizards are native to certain areas of the world from the wetlands to the deserts and haven’t been a problem for us yet. Although they do have the possibility to contain what is called salmanilla.
Bird feathers : Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Aves
Bird and the bees have been around for quite some time and co-existing has been moving along. Although recently and presently we are experiencing problems with avian flu. This has taken its toll on many people hospitalizing and even threatening the lives of those who come in contact with it.
Pairie dogs playing in dirt: Cynomys ludovicianus (black-tailed prairie dog)
These little guys were digging holes in a vacant area in Colorado and I noticed that children had even built a fort close to the area where these little guys were taking up residency.
Holding my cat: Felidae: symbiotic
Cats domesticated and farrow have been around for hundreds of years. We have co-existed with them and adapted threw the years. But I have heard of cat scratch fever as well as the little box changing and aromas that are inhaled are not good for pregnant people to be around.
Feeding a Tiger: Panthera tigris : predator/prey
We are co-existing with these great creatures but actually it is not suggested that we jump in their and play with them. When I fed this guy I had to put on latex gloves and wash my hands with sanitizer. So I am not sure if I actually had to wear these gloves to protect me from getting something from them or to prevent me from giving something to the tiger!
Feeding a goldfish: Carassius auratus: symbiotic
The goldfish is domesticated and considered to be a great pet. Algae does grow in the side of the aquarium and the water actually has a tendency to smell. I would not suggest drinking that as a cocktail.
Mistletoe growing on tree: Arceuthobium campylopodum: parasitic
Mistletoe is not harmful to us but it does pose a threat to the trees it preys upon. If the mistletoe is not taken under control then it could lead to the overall destruction to the tree it is living off of.
Dead heading flowering bushes: Magnoliophyta:mutualism: it helps in prolonging the blooming fo these flowers. We do co-exist with many plants and some of which that if ingested may cause illness, death, or joy.
Biting finger nail: Commensal: there are not harmful germs under the nails but after a day in the experiences of life there could be colds, flu, and harmful bacteria that could be found under the nails.
Hummingbird on bush: Trochilidae: mutualism: Hummingbirds are great for our environment they help in spreading pollen from plant to plant. Therefore leading to mreo and more hybrid or populating plants.
Lab 2 Population
1. What was your high fertility rate country and what was its fertility rate?The high fertility rate country I chose was the United States. The fertility rate was 2 children. Benin was a small country but a high rise in population. Fertility rate of 6.90 and the life expectancy was 50.9
2. What was your low fertility rate country and what was its fertility rate?Ireland was the country I picked and the fertility rate was 2 children.
3. The initial demographic "shape" of your high fertility rate country should have been a pyramid, with high population in young age groups. Explain why high fertility rate results in a high percentage of young people in the population. How does this affect future population growth? Younger people being born in vast numbers can throw off the number of people that would be able to marry. With people living longer. There leaves a gap. Many kids being born. People living longer might pose a problem as well. Young people having babies and “flooding the market” so to speak.4. Your low fertility rate country might have had a more oval-shaped curve with high population in middle age groups. This is especially exaggerated if the fertility rate is below 2.00. Explain why low fertility rate leads to lots of middle-aged people. Lots of middle aged people are vastly populated countries with low fertility rates because there are not as many people being born and the people populating the region of aging. This could be associated with a larger fertility rate during their generation.5. Write ten adjectives or descriptive phrases for what you might expect life, people's attitudes, conditions on the streets, etc. will be like in each of those situations. Imagine a situation with lots of middle-aged and older people in the population and write ten quick "brain-storm" descriptors for you think it would be like (Prescott, Arizona?). Then do the same for a situation with lots of children in the population.
Middle aged and older people adjectives
Traditional, educated, involved, mellow, stable, crafty, dog lovers, caring, loving, tired, old-fashioned, and ethical
Younger populated areas:
Reckless, violence, death, rowdy, athletic, energetic, school oriented, friendly, laughter, smiles, and carefree
Ethical Essay
When thinking about who should reproduce and who should not it is a question of personal in nature. It is all a matter of opinion that can not just be decided by the government. In China, they decided that there should be a limit to how many children each family could actually have. This not only aided in reducing the amount of energy used and strain on the country but now the country is in much better shape. Although I understand why it was done. If you are in a sinking ship do you stay on board or begin to identify the problem and fix it? With China they decided to fix the problem and have been reaping the benefits of such restrictions. We live in a society of freedom of speech and it was often thought by Americans that the restrictions placed on people as to how many children they may be able or not be able to produce would be a violation. But if you look at the broader picture population restrictions it is a means to an ends. If the country is struggling to make it work and provide for the people populating it then something needs to be done. This is what is happening in many third world countries and it is not getting them any further ahead of the poverty, sickness, and overwhelming incidents of birth defects and in Africa’s case the out of control epidemic of the AIDS virus. Maybe population regulations or sterilization would be beneficial to those countries. I am not sure if denying monies to those countries would be of assistance if anything it would lead to starvation and absence of medical availabilities would not benefit them in anyway unless death is the answer. We also need to look at our own environment. We are losing farming land due to land developments for subdivisions. We are having water shortages and restrictions for people due to usage and drought reasons. We are one of the largest polluting driven countries in the world and we are all, throughout the world, contributing to the depletion of the rainforest and the ozone layer. We have to look out for our future. Many times we just live in the now but we need to think of our children and the future that they might have. Population restrictions might be the necessary step that is needed in order to get the out of control population growth throughout the world under control. I don’t think that it needs to come down to deciding who is capable of raising a child. Or it needs to go into the background of the person as to whether or not this person should procreate but instead maybe restrictions on the amount of children a person can have might be a consideration. I mean goodness we have some people who have 10 and 12 children. This might have been necessary in the times of ranches and needing the helping hands to aid in the maintenance of the property. In third world countries sterilization has often been brought to the for front as a way of reducing population growth but it is a controversial idea. In talking about population reduction maybe instead of the families benefiting in the number of children they have an alternative to that might be offering stimulus packages for those people who only have 2 children or less. Not making it a requirement but instead an incentive because we are helping the environment. I mean people receive rebates for using solar power on their homes why not extend those to families that are helping to reduce the population growth.
Self Evaluation
1. What were the three aspects of the assignments I've submitted that I am most proud of?
I am proud of my ethical essay, compendium reviews and I enjoyed reading the web links.
2. What two aspects of my submitted assignments do I believe could have used some improvement? I have spend endless hours trying to figure out what in the world is going on with downloading pictures. So I am not happy with not having that on here. I think I could have done better on the final lab with more examples.
3. What do I believe my overall grade should be for this unit?
I think I should get a B because I don't have my pictures up. I am going to keep on trying so I am thinking maybe an A for effort.
4. How could I perform better in the next unit?
By not waiting until the last minute to post my posts. I was so excited about having teh work completed and to be done with the course and that quickly turned to aggrevation in an instant because it was not going as planned.
At what moment during this unit did you feel most engaged with the course?
I loved the chapters on evolution. I think that is very interesting. Fossils and foot steps in teh past always intrigue me.
At what moment unit did you feel most distanced from the course?
I felt like that when I was learning about meiosis and mitosis.
What action that anyone (teacher or student) took during this unit that find most affirming and helpful?
I liked the way the teacher was just an email away. Although... I felt frustrated because I could have turned in teh information if I had been able to just take it over to him.
What action that anyone (teacher or student) took during this unit did you find most puzzling or confusing? nothing.
What about this unit surprised you the most? (This could be something about your own reactions to the course, something that someone did, or anything else that occurs to you.)
I think this unit made me really stop and reflect and think about about the past and where we might have come from and the future where is the world going to be in 40 years! VERY INTERESTING!
COMPENDIUM REVIEWS & TABLE OF CONTENTS
Table Of Contents
Reproduction
Chapters 16 & 17
Compendium Review
I. Chromosomes, Cell Division, & Cell Cycle
A. The Cell Cycle
1. Interphase
B. The Chromosomes
1. Chromosomal Condensation
2. Chromatids & Chromosomes
C. Cell Division
1. Mitosis 4 phases
2. Cytokinesis
Cell division plays an important role in maintaining homeostasis and aids the body in repairing damaged tissues and organs. This division in cells is part of the cell’s life cycle of cell cycle. In consists of two parts; interphase and the cell division. During cell division the nucleus and cytoplasm divide and split the cell somewhat equally and this in turn makes two individual cells.
-Interphase is the period of time that displays intense metabolic activity between cell divisions and is divided into three phases; G1 (gap 1), S phase (synthesis phase), and G2 (gap 2).
G1 begins immediately and the cell carries on day-to-day activities. During this phase the cell makes RNA, proteins, and other molecules. S phase is where DNA replicates. After replication, each chromosome in the nucleus of the cell contains two chromatin fibers, or chromatids. The G2 phase is where the mitochondria divide and the precursors of the spindle fibers and the chromosomes begin to condense. This period of time is relatively inactive and is a shorter period of time.
-After interphase is when cell division begins. The cell replicates its organelles and molecules are needed by the two daughter cells. Nuclear division is commonly known as mitosis. Mitosis involves a series of dramatic structural changes in chromosomes. During this process the chromosomes becomes more compact structures clearly visible in ordinary light microscopic preparations.
-The human cell has 46 chromosomes or 23 pairs that contain all of the genetic information required to control cellular activity. Chromosomes are described as homogeneous. Homogeneous chromosomes contain genes that control the same inherited traits. Cells that contain the full number of chromosomes (46) are considered to be diploid (two fold) Germ cells (sperm and ovum) are called hapoid because they contain half the chromosomes of the somatic cells. Germ cells are produced by a special kind of cell division known as meiosis.
-Chromosomal condensation happens after replication and it facilitates mitosis usually during prophase. During this the cells begin to coil, compacting in much the same way that a stretched phone cord shortens and compacts when the tension is removed. While the chromosomes are in a condensed state they are inactive and unable to produce either DNA or RNA. Condensation allows chromosomal separation which makes it easier to study them. Chromosomes are arranged by size and other features form a karyotype. It is used to help geneticists count the chromosomes and to locate potential abnormalities. It is especially important to mothers-to-be because it allows for a process to be done called an amniocentesis. The is where the doctor will extract fluid that surrounds the baby through a needle that is inserted through the mother’s abdomen. This fluid contains the baby cells and they can be separated where they are then grown in cultures. They continue to divide and grow. After which a chemical substance is added and that aids in stopping the cell division. Then they are removed from the culture and placed on a glass slide, photographed and analyzed. Then with the help of computer software the chromosomes are arranged in pairs and then looked at to see if there are any obvious defects.
Here are some helpful terminology when talking about chromosomes.
*chromatin is a strand of DNA and associated histones (globular proteins).
*chromatin fibers are strands of chromatin.
*chromosomes consists of one or two chromatin fibers.
*chromatid is one of the chromatin fibers of a replicated chromosome
*centromere is a region of each chromatid to which a sister chromosome is attached.
-The number of chromatids in chromosomes varies depending on the stage of the cell cycle. Each chromosome is made of two chromatids that are held together at the centromere.
-Mitosis is divided into four stages called prophase, metaphase, anaphase, and telophase.
-Prophase begins just after interphase and the replicated chromosomes condense. The nucleoli are regions of active rRNA synthesis. In the cytoplasm, the cell’s centrioles separate. The mitotic spindle forms. The mitotic spindle is an elaborate array of microtubules. It is also responsible for the movement of the chromosomes. Late in prophase the nuclear envelope begins to break down. This permit’s the chromosomal fibers of the mitotic spindle to attach to the chromosomes, setting the stage for the next step, metaphase.
-Before chromosomes can be divided equally, they are lined up in the center of the cell with their centromeres located along the equatorial plane. This aids in the separation of chromatids.
-Anaphase is when the chromatids of each chromosome begin to separate. The chromatids of the homologous chromosomes are drawn toward opposite poles of the mitotic spindle.
-The final stage of cell division is called telophase. This is when the chromosomes complete their migration to the poles. This stage involved a series of changes in the nuclei that are basically the exact opposite of prophase. During telophase, membranes form around the chromosomes of each new (daughter) cell. This phase ends when the nuclei of the daughter cells appear to be in interphase.
-Cytokinesis is the division of the cytoplasm. This is possible by the contraction of the microfilaments beneath the cell membrane. This usually happens in the latter part of anaphase or early in telophase.
-Many factors appear to be a part of the cell cycle from hormones to growth-promoting and growth inhibiting factors. These factors may act directly on the cytoplasm but more likely stimulate changes in the genes in the nucleus that regulate the cell cycle.
Table of Contents
II. Principles of the Human Heredity
A. Meiosis & Gamete Formation
1. Meiosis I
2. Meiosis II
3. Gamete Production
B. Principles of Heredity
1. Blending of Traits
2. Principles of Segregation
3. Dominant and Recessive Genes
4. Principle of Independent Assortment
C. Mendelian Genetics in Humans
1. Autosomoal-Recessive Traits
2. Autosomal-Dominant Traits
D. Variations in Mendelian Genetics
1. Incomplete Dominance
2. Multiple Alleles
3. Polygenic Inheritance
4. Crossing Over
5. Human Genome Project
E. Sex-Linked Genes
1. Sex-Influenced Genes
F. Chromosomal Abnormalities & genetic Counseling
1. Defects in Chromosomal Structure
2. Genetic Screening
During gamete formation, germ cells, undergo a special kind of division called meiosis, which reduces the number of chromosomes in half.
-Meiosis I has the same four steps as mitosis; prophase, metaphase, anaphase, and telophase.
During prohase I, the chromosomes condese and the homogeneous chromosomes pair up.
During metaphase I homogeneous pairs line up in the equatorial plate.
During anaphase I the pairs separate with one member of the pair each going to each daughter cell. Each daughter cell ends up with half the number of chromosomes (23) of parent cells (46) Each chromosome contains two chromatids and since the chromosomes decrease in half while going through this process it is called reduction division.
-Mitosis II is like mitosis in many ways and this is the second cell division. The cells start out as haploid. The chromosomes of haploid cells condense during prophase II. Chromosomes disassociate during anaphase II and go to each pole.
-Gamete production in males meiosis produces four gametes, in females it produces only one. The diploid cell in the gamete-producing organ, the testis gives rise to four sperm cells. The single diploid cell gives rise to only one gamete the egg or the ovum.
-Much of the work in the early knowledge on heredity came from the work of Gregor Mendel.
-Blending of traits was first discovered by Mendel. When the traits he studied did not blend.
-When talking about the principles of segregation the parents contribute equally to the characteristics of their offspring. The gametes of the parents combine to produce an offspring and because each gamete contains one hereditary factor for each trait. Mendel also concluded that the contributions of the parents are equal.
-Mendel also figured out that either plants are recessive or dominant. A recessive factor is expressed only when the dominant factor is missing. An alternative form of the same gene is called an allele.
-Independent assortment principles say that genes on different chromosomes segregate independently during gamete formation.
-Autosomal-recessive traits are expressed only when both the alleles are recessive. Sex chromosomes are needed in determining the sex of the baby to be born.
-Albinism is one of the most common genetic defects known to science. Melanin is the brown pigment responsible in the coloration of the eyes, skin, and hair. The skin in an albino is pale and the hair is white. It is easier for the skin to be sunburned.
-Cystic fibrosis is an autonomic-recessive disease that leads to early death. Over time the pancreas begin to degenerate and fibrosis tissue replaces glandular tissue. The respiratory system of victims of cystic fibrosis produce copious amounts of mucus. It is also one of the most common genetic diseases.
-Autosomal-dominant traits are present in every one of us.
Incomplete dominance results in a kind of blending of traits. Incomplete dominance occurs in many human disorders and one being sickle cell disease. This disease effects the blood and affects mostly African Americans. By having this disease it does make them immune to the HIV virus. Which I think it very interesting.
-Some genes have multiple alleles. There are four possible blood types; A, B, AB, & O.
-Some traits are determined by more then one gene pair. Skin color is controlled by as many as 8 genes. This type of inheritance is called polygenic inheritance. It is also responsible for height, weight, intelligence, and many behavioral traits.
-Crossing over is a genetic swapping that occurs in meiosis. Those genes that are located on the same chromosome tend to be inherited together and are said to be linked. Crossing-over can occur anywhere along the length of the chromosome.
-Human genome project I find very interesting. It seeks to determine the sequence of bases in human DNA and the location of all of the genes. It started in 1991.
-Sex linked genes can determine baldness and women carry the gene that dominants in supplying that gene.
-Abnormal chromosome numbers generally result from a failure of chromosomes to separate during gamete production.
-One of the most common triomies is down syndrome. One out of every 700 babies born in the US has down syndrome.
-Nondisjunction of sex chromosomes can occur in both autosomes and sex chromosomes. Klinefelter syndrome occurs when an ovum with an extra X chromosome is fertilized by a y bearing sperm resulting in a XXY genotype.
-Genetic disorders may also result from variations in chromosome structure. Deletions which are a loss of a piece of chromosome. Translocations which is breakage and reattachment somewhere else.
-Genetic screening allows parents to determine whether they will have a genetically normal baby. Amniocentesis is usually recommended only if one or more of the following conditions are met
1) a woman that is over 25
2) she has already delivered a baby with a genetic defect
3) she is a carrier of an X-linked genetic disorder
4) she or the father has a known chromosomal or genetic abnormality
Human Development & Aging
Chpt 22
Table of Contents
I. Fertilization
1. Passage of female reproductive tract
Sperm mobility and penetration
2. Zygote formation
II. Pre-embryonic development
1. Implantation
2. Ectopic pregnancy
3. Placental hormones
4. Amnion
III. Embryonic Development
IV. Fetal development
1. Fetal Circulatory
V. Birth Defects
VI. Child Birth and Lactation
1. Stages of birth
2. Lactation
VII. Aging and Death
1. Decline of cell numbers and functions
2. Death
-The sperm and the egg of humans unite during fertilization. This usually takes place in the upper third of the uterine tube. Sperm is deposited in the vagina and it reaches the site of fertilization by swimming. Muscle contractions also aids in the wall of the uterine tube and uterus and it pushes the sperm on its way.
Sperm dissolve away the cells surrounding the oocyte and then they bore through the zona pellucida and the contact the plasma membrane. The first one to contact the membrane fertilizes the oocyte. Further sperm penetration is blocked. The chromosomes of the sperm and oocyte duplicate and merge in the center of the cell, where mitosis begins.
Human development is divided into three stages: pre-embryonic, embryonic, and fetal.
-During pre-embryonic development the zygote undergoes rapid cellular division forming a morula. The morula is then converted into a blastula, a structure with a hollow cavity, called a blastocyst in humans. The blastcyst consists of a clump of cells. The inner cell mass (ICM) becomes and embryo and the trophoblast gives rise to the embryonic portion of the placenta.
While the placenta is forming a layer of cells form the ICM of the blast cyst separates from it and forms an amnion. The amnion fills with fluid and enlarges during embryonic and fetal development, eventually surrounding the entire embryo and fetus protecting them during development.
-The ICM separates into three germ cell layers; ectoderm, mesoderm, and endoderm. The formation of the three primary germ layers marks the beginning of the embryonic development. The organs develop from these three primary tissues during organogenesis.
-Fetal development begins at 8 weeks after fertilization and is primarily a period of fetal growth because most of the organ systems have developed or are under development.
The placenta produces several hormones that play an important role in reproduction. HCG maintains the corpus luteum during pregnancy. Progesterone and estrogen stimulate uterine growth and the development of the glands and the ducts of the breasts. The placenta delivers oxygen and nutrients to the fetal blood nd removes waste products from it.
-The fetal circulatory system is very much like th adult circulatory system, except that it contains three pathways that allow blood to bypass the lungs and liver, which are developing but not functioning. At birth these bypasses close up and the adult pattern of circulation develops.
-Birth defects arise from chemical, biological, and physical agents. The effects of these agents is related to the time of exposure, the nature of the agent, and the dose. A defect is most likely to arise if a woman is exposed during an embryonic period when the organs are forming.
-Labor consists of intense and frequent uterine contractions believed to be caused by the release of small amounts of fetal oxytocin prior to birth. Fetal oxytocin stimulates the release of prostaglandins by the placenta. Oxytocin and prostaglandins stimulate contractions in the sensitized uterine musculature.
-Maternal osytocin is also released, augmenting muscle contractions. As uterine contractions increase, they cause more maternal oxytocin to be released, which stimulates stronger contractions and more oxytocin release, a positive feedback that continues until the baby is born. Labor consists of dilation, expulsion, and placental stages. The breast consist primarily of fat and connective tissue interspersed with milk-producing glandular tissue and ducts. During pregnancy, the glands and ducts proliferate under the influence of placental and ovarian estrogen and progesterone.
-Milk production is induced by maternal prolactin. Before milk begins, the breast produce a small quantities of a protein-rich fluid called colostrum. The baby usually consumes the fluid and it enriches their bodies as well as aiding in building up their immune system.
-Aging is a progressive deterioration of the body’s homeostatic abilities and the gradual deterioration of the function of the body’s organs. These changes result in at least two of the factors; a decrease in the number of cells in the organs and a decline in the function of existing cells. Death is the result.
Human Evolution
Chpt 23
Compendium review
I. The Evolution of Life
1. Chemical evolution
2. First cells and Eukaryotes
II. How Evolution Works
1. Natural Selection, Genetic Variation
III. Evidence Supporting Evolution
1. Fossils
2. Biochemical Similarities
IV. Early primate Evolution
V. Evolution of Australopithecines
VI. Evolution of Genes Homo
1. Human races
Scientists believe that the Earth and the sun and the rest of the system came from and enormous cloud of cosmic dust and gas that gave rise to the Earth and the sun. The Earth formed about 4.5 billion years ago.
-The evolution of life probably began in the sea and is divided into 3 phases: chemical evolution, cellular evolution, and the evolution of the multicultural organisms.
-Chemical evolutions scientists think that about 4 billion years ago. Simple inorganic chemicals that were dissolved in the seas combined to form small organic molecules. Over time, the organic molecules combine to form polymers, small proteins and nucleic acids. These polymers combined to from aggregates that may have been the precursors of cells.
-The first few cells arose from the primitive aggregates. They contained primitive enzymes and simple genes and may have derived nourishment from organic molecules they absorbed from the environment.
-Over time scientists believed that photosynthesis envolved further and the new photosynthetic organisms began to produce oxygen.
-Prokaryotes emerged in about 3.5 billion years ago. Eukaryotes evolved about 1.2 billion years ago. The evolution of the eukaryotes opened the door for the evolution of multicultural organisms.
-A variety of multicultural plants and animals evolved from the single celled eukaryotes in the oceans. The ozone layer developed and life on land became possible.
-Evolution has produced a great diversity of organisms. Evolution takes place because of the genetic variation and natural selection. Genetic variation in a species arises from many factors such as mutations and from new genetic combinations resulting from sexual reproduction. Genetic variations in traits that may offer some organisms an advantage over others, giving them a better chance of surviving, reproducing, and passing the genes on to future generations. Beneficial traits are preserved in a population by natural selection.
-The scientific knowledge in support of evolution is rich and varied. The fossil record, anatomical similarities in groups of organisms, the common biochemical makeup of organisms, similar embryological development among many groups of organisms. The experimental evidence all support the theory of evolution by natural selection.
-When talking about early primate evolution humans belong to this order. Primates are characterized by grasping hands, forward-looking eyes and large brains.
*Timeline*
Based on fossil evidence it appears that the primates evolved from a mammalian insectivore that resembled the modern-day tree shrew and lived about 80 million years ago. They think that humans evolved from early apelike creatures.
-The first human primate belonged to the genus Australopithecus. The oldest known skeleton was unearthed in Africa 3.5 million years old. It belongs to the group Australopithecus afarensis. It stood about 3 ft tall and its brain was just slightly bigger then an ape’s but they were thinking that it probably walked erect.
-3 million years ago A. afarensis was replaced by other species A. africanus which was slightly taller and it had even a bigger brain.
-2.3 million years ago A. robustus emerged. It was taller and heavier and had an even larger brain.
-2.2 million years ago the forth species emerged and it was called A. boisei.
-Many paleontologists believe that A. afarensis also gave rise to the genus Homo, and ancestors of the modern humans. Homo sapiens. Some people still think that it might had emerged from another ancestor all together. The earliest discovery of a human skull was 1.8 million years ago in Tanzania. It belonged to the homo habilis.
-200,000 years ago after the emergence of homo habilis the homo erectus arose. Homo erectus unlike it predecessors that remained in Africa these guys moved to Europe and Asia. They stood about 5 ft tall and used fire and many different kinds of tools but their brains smaller than ours and we are believed to have some from them directly.
-Homo sapiens emerged about 300,000 years ago and consisted of two subspecies: homo sapiens neanderthalensis and homo sapiens sapiens.
-The Neanderthals lived in caves and camps in Europe and Asia approximately 40,000 years ago. Some archaeologists believe that they were replaced by modern humans, the CroMagnons and earliest members of the homo sapiens sapiens. The Cro-magnons first appeared in Africa and then spread across Europe and Northern Asia and wiped out the Neanderthals or maybe even copulating with them.
-Other the course of many years, the human population moved and went far and wide. They inhabited many climate changes and became very good at adapting and overcoming the various complications that arose. With these travels the formation of different cultures began to form. Many adaptations that make up the different races are thought ot have happened due to the races and different population groups adapting to the environment.
Table of Contents
Ecology & the Environment
Chpt 24
I. Introduction to the Ecosystems
1. Biosphere
2. Biomes & Aquatic Life Zones
II. Ecosystem Function
1. Producers & Food Chains
2. Energy & Nutrient Flows
3. Trophic Levels
4. Nutrient Cycles
III. Overshooting the Earth’s Carrying Capacity
1. Polution
2. Resources
IV. Overpopulation: Problems and Solutions
V. Resource Depletion
1. Forest, Soil, & Water
VI. Pollution
1. Global Warming and its Impacts
2. Ozone layer
Humans survival is dependent on the resources that surround us today. It is vital to keep these resources available and not to exhaust them otherwise we could face extinction ourselves. Ecology is the study of ecosystems. It is the examination of organisms and their environment and many of the interactions between them. The living skin of the planet is called the biosphere. It goes from the bottoms of the oceans to the tippy top of the highest mountains. The only thing that is necessary for this process to take place is the addition of sunlight. Too much sun and heat can be detrimental to plants and animals as well as not enough sun. It is a proper balance between the environment and the dependency of sunlight.
-The biosphere is a closed system in which materials are recycled over and over again. I have heard this referred to as the circle of life. The Earth;s surface is divided into large biomes eah with a characteristic climate and characteristic to plant and animal life. The ocean is referred to as a biological region known as the aquatic life zones.
-The ecosystem consists of a community of organisms, its environments, and their interactions.A group of organisms with the same species living in a specific region constitutes a population. If you have two or more populations occupying a region it is called a community. The area that a species being human or animal is called a habitat. A Species’ niche is made up of its habitat and where they are on the ladder of the food chain.
-Virtually all life on Earth depends on plants and other producers, organisms that synthesize organic materials from sunlight, carry carbon dioxide, and water via photosynthesis. Organisms depending on producers for food are called consumers. Four types of consumers are present and they are herbivores, carnivores, omnivores, and detrivores.
-When talking about the food chain we are all a part of it.
The food chains begin at plants that are consumed by grazers (herbivores) and this is called the grazer food chain. Those that feed off of dead organisms or wastes are a part of the decomposer food chain. The position where an organism is located on the food chain is called the trophic level.
Nutrients are necessary for life growth and for life to flow through the nutrient cycles.
-The term secession refers to a series of changes in the ecosystem in which one community replaces another until a mature ecosystem is produced. Primary succession is where a community previously existed. Secondary succession occurs where a community was destroyed by natural or human events. I thought of Pompay.
-Although environmental problems vary from one nation to another they are all the result of human populations exceeding the carrying capacity of the environment. Carrying capacity is the number of organisms an ecosystem can support indefinitely and is determined by food and resource supplies and by the capacity of the environment to assimilate or destroy waste products of organisms.
Overpopulation occurs anytime a population exceeds it carrying capacity. This can be by looking at the food ratios available lack of resources, and excessive pollution. It can be all three or even one of the three that could be harmful.
-When talking huge numbers of population growth I think of Africa, Asia and Latin America. Resource shortages and food depletion are the main concerns or problems in this area. Many experts believe that industrialized areas are overpopulated . I thought of New York when immigrants were flooding the area and there were extreme pollutants and sickness due to the inhumane ways of discarding wastes and such. It was industrial and it suffered.
-Human population can be sumed up in 6 words; too many people, reproducing too rapidly, which results in resource shortages, excessive pollution, and poverty.
Resource depletion is a huge problem and concern. Humans use renewable and nonrenewable resources and all of which are depleting. Forest are being cut down faster then they can be replaced. That is why bamboo is a great option for building and such because it grows at a rapid rate. There are many things we can do to help in the environmental problems… GO green! Recycle, plant trees, soil conservation, population control, and drive energy efficient cars but there are many other stategies that need to be implemented in order for it to work or help! The soils are being eroded from rangeland and farmland. The effects of this will be food production later down the road. Many areas in the world suffer from water shortages. With the rise in population this will get far worse before it gets better. I saw on the news the other day about huge sin holes that were evident because of the underground streams being used and causing the ground to give out.
-Oil supplies are also finite. Global oil is expected to peak between the years of 2004 and 2010. Production may not be able to meet demand. An alternative to this catastrophy would be to use renewable fuels, and a sustainable energy supply.
-Pollution from human activities is overwhelming and it has a huge strain on the nutrient cycles and assisting is destroying homeostasis. One of the most serious threats of pollution is carbon dioxide. Carbon dioxide is a greenhouse gas that traps heat in the Earth's atmosphere. This increases the planet's surface temperature, altering this climate, shifting the rainfall patterns and agricultural zones, flooding low lying regions and destroying many species that cannot adapt to the sudden change in temperature. To slow the effects of global warming scientists recommend massive reforestation projects and dramatic improvements in the efficiency of the fossil-fuel combustion and development of alternative fuels. There are two gases that are the gaseous pollutants ans they are sulfur dioxide and nitrogent dioxide and they are released from power plants, factories, automobiles, and other sources.
-The ozone layer encircles the Earth, trapping unltraviolet light. It is being destroyed by CFC's and other pollutants.
Reproduction
Chapters 16 & 17
Compendium Review
I. Chromosomes, Cell Division, & Cell Cycle
A. The Cell Cycle
1. Interphase
B. The Chromosomes
1. Chromosomal Condensation
2. Chromatids & Chromosomes
C. Cell Division
1. Mitosis 4 phases
2. Cytokinesis
Cell division plays an important role in maintaining homeostasis and aids the body in repairing damaged tissues and organs. This division in cells is part of the cell’s life cycle of cell cycle. In consists of two parts; interphase and the cell division. During cell division the nucleus and cytoplasm divide and split the cell somewhat equally and this in turn makes two individual cells.
-Interphase is the period of time that displays intense metabolic activity between cell divisions and is divided into three phases; G1 (gap 1), S phase (synthesis phase), and G2 (gap 2).
G1 begins immediately and the cell carries on day-to-day activities. During this phase the cell makes RNA, proteins, and other molecules. S phase is where DNA replicates. After replication, each chromosome in the nucleus of the cell contains two chromatin fibers, or chromatids. The G2 phase is where the mitochondria divide and the precursors of the spindle fibers and the chromosomes begin to condense. This period of time is relatively inactive and is a shorter period of time.
-After interphase is when cell division begins. The cell replicates its organelles and molecules are needed by the two daughter cells. Nuclear division is commonly known as mitosis. Mitosis involves a series of dramatic structural changes in chromosomes. During this process the chromosomes becomes more compact structures clearly visible in ordinary light microscopic preparations.
-The human cell has 46 chromosomes or 23 pairs that contain all of the genetic information required to control cellular activity. Chromosomes are described as homogeneous. Homogeneous chromosomes contain genes that control the same inherited traits. Cells that contain the full number of chromosomes (46) are considered to be diploid (two fold) Germ cells (sperm and ovum) are called hapoid because they contain half the chromosomes of the somatic cells. Germ cells are produced by a special kind of cell division known as meiosis.
-Chromosomal condensation happens after replication and it facilitates mitosis usually during prophase. During this the cells begin to coil, compacting in much the same way that a stretched phone cord shortens and compacts when the tension is removed. While the chromosomes are in a condensed state they are inactive and unable to produce either DNA or RNA. Condensation allows chromosomal separation which makes it easier to study them. Chromosomes are arranged by size and other features form a karyotype. It is used to help geneticists count the chromosomes and to locate potential abnormalities. It is especially important to mothers-to-be because it allows for a process to be done called an amniocentesis. The is where the doctor will extract fluid that surrounds the baby through a needle that is inserted through the mother’s abdomen. This fluid contains the baby cells and they can be separated where they are then grown in cultures. They continue to divide and grow. After which a chemical substance is added and that aids in stopping the cell division. Then they are removed from the culture and placed on a glass slide, photographed and analyzed. Then with the help of computer software the chromosomes are arranged in pairs and then looked at to see if there are any obvious defects.
Here are some helpful terminology when talking about chromosomes.
*chromatin is a strand of DNA and associated histones (globular proteins).
*chromatin fibers are strands of chromatin.
*chromosomes consists of one or two chromatin fibers.
*chromatid is one of the chromatin fibers of a replicated chromosome
*centromere is a region of each chromatid to which a sister chromosome is attached.
-The number of chromatids in chromosomes varies depending on the stage of the cell cycle. Each chromosome is made of two chromatids that are held together at the centromere.
-Mitosis is divided into four stages called prophase, metaphase, anaphase, and telophase.
-Prophase begins just after interphase and the replicated chromosomes condense. The nucleoli are regions of active rRNA synthesis. In the cytoplasm, the cell’s centrioles separate. The mitotic spindle forms. The mitotic spindle is an elaborate array of microtubules. It is also responsible for the movement of the chromosomes. Late in prophase the nuclear envelope begins to break down. This permit’s the chromosomal fibers of the mitotic spindle to attach to the chromosomes, setting the stage for the next step, metaphase.
-Before chromosomes can be divided equally, they are lined up in the center of the cell with their centromeres located along the equatorial plane. This aids in the separation of chromatids.
-Anaphase is when the chromatids of each chromosome begin to separate. The chromatids of the homologous chromosomes are drawn toward opposite poles of the mitotic spindle.
-The final stage of cell division is called telophase. This is when the chromosomes complete their migration to the poles. This stage involved a series of changes in the nuclei that are basically the exact opposite of prophase. During telophase, membranes form around the chromosomes of each new (daughter) cell. This phase ends when the nuclei of the daughter cells appear to be in interphase.
-Cytokinesis is the division of the cytoplasm. This is possible by the contraction of the microfilaments beneath the cell membrane. This usually happens in the latter part of anaphase or early in telophase.
-Many factors appear to be a part of the cell cycle from hormones to growth-promoting and growth inhibiting factors. These factors may act directly on the cytoplasm but more likely stimulate changes in the genes in the nucleus that regulate the cell cycle.
Table of Contents
II. Principles of the Human Heredity
A. Meiosis & Gamete Formation
1. Meiosis I
2. Meiosis II
3. Gamete Production
B. Principles of Heredity
1. Blending of Traits
2. Principles of Segregation
3. Dominant and Recessive Genes
4. Principle of Independent Assortment
C. Mendelian Genetics in Humans
1. Autosomoal-Recessive Traits
2. Autosomal-Dominant Traits
D. Variations in Mendelian Genetics
1. Incomplete Dominance
2. Multiple Alleles
3. Polygenic Inheritance
4. Crossing Over
5. Human Genome Project
E. Sex-Linked Genes
1. Sex-Influenced Genes
F. Chromosomal Abnormalities & genetic Counseling
1. Defects in Chromosomal Structure
2. Genetic Screening
During gamete formation, germ cells, undergo a special kind of division called meiosis, which reduces the number of chromosomes in half.
-Meiosis I has the same four steps as mitosis; prophase, metaphase, anaphase, and telophase.
During prohase I, the chromosomes condese and the homogeneous chromosomes pair up.
During metaphase I homogeneous pairs line up in the equatorial plate.
During anaphase I the pairs separate with one member of the pair each going to each daughter cell. Each daughter cell ends up with half the number of chromosomes (23) of parent cells (46) Each chromosome contains two chromatids and since the chromosomes decrease in half while going through this process it is called reduction division.
-Mitosis II is like mitosis in many ways and this is the second cell division. The cells start out as haploid. The chromosomes of haploid cells condense during prophase II. Chromosomes disassociate during anaphase II and go to each pole.
-Gamete production in males meiosis produces four gametes, in females it produces only one. The diploid cell in the gamete-producing organ, the testis gives rise to four sperm cells. The single diploid cell gives rise to only one gamete the egg or the ovum.
-Much of the work in the early knowledge on heredity came from the work of Gregor Mendel.
-Blending of traits was first discovered by Mendel. When the traits he studied did not blend.
-When talking about the principles of segregation the parents contribute equally to the characteristics of their offspring. The gametes of the parents combine to produce an offspring and because each gamete contains one hereditary factor for each trait. Mendel also concluded that the contributions of the parents are equal.
-Mendel also figured out that either plants are recessive or dominant. A recessive factor is expressed only when the dominant factor is missing. An alternative form of the same gene is called an allele.
-Independent assortment principles say that genes on different chromosomes segregate independently during gamete formation.
-Autosomal-recessive traits are expressed only when both the alleles are recessive. Sex chromosomes are needed in determining the sex of the baby to be born.
-Albinism is one of the most common genetic defects known to science. Melanin is the brown pigment responsible in the coloration of the eyes, skin, and hair. The skin in an albino is pale and the hair is white. It is easier for the skin to be sunburned.
-Cystic fibrosis is an autonomic-recessive disease that leads to early death. Over time the pancreas begin to degenerate and fibrosis tissue replaces glandular tissue. The respiratory system of victims of cystic fibrosis produce copious amounts of mucus. It is also one of the most common genetic diseases.
-Autosomal-dominant traits are present in every one of us.
Incomplete dominance results in a kind of blending of traits. Incomplete dominance occurs in many human disorders and one being sickle cell disease. This disease effects the blood and affects mostly African Americans. By having this disease it does make them immune to the HIV virus. Which I think it very interesting.
-Some genes have multiple alleles. There are four possible blood types; A, B, AB, & O.
-Some traits are determined by more then one gene pair. Skin color is controlled by as many as 8 genes. This type of inheritance is called polygenic inheritance. It is also responsible for height, weight, intelligence, and many behavioral traits.
-Crossing over is a genetic swapping that occurs in meiosis. Those genes that are located on the same chromosome tend to be inherited together and are said to be linked. Crossing-over can occur anywhere along the length of the chromosome.
-Human genome project I find very interesting. It seeks to determine the sequence of bases in human DNA and the location of all of the genes. It started in 1991.
-Sex linked genes can determine baldness and women carry the gene that dominants in supplying that gene.
-Abnormal chromosome numbers generally result from a failure of chromosomes to separate during gamete production.
-One of the most common triomies is down syndrome. One out of every 700 babies born in the US has down syndrome.
-Nondisjunction of sex chromosomes can occur in both autosomes and sex chromosomes. Klinefelter syndrome occurs when an ovum with an extra X chromosome is fertilized by a y bearing sperm resulting in a XXY genotype.
-Genetic disorders may also result from variations in chromosome structure. Deletions which are a loss of a piece of chromosome. Translocations which is breakage and reattachment somewhere else.
-Genetic screening allows parents to determine whether they will have a genetically normal baby. Amniocentesis is usually recommended only if one or more of the following conditions are met
1) a woman that is over 25
2) she has already delivered a baby with a genetic defect
3) she is a carrier of an X-linked genetic disorder
4) she or the father has a known chromosomal or genetic abnormality
Human Development & Aging
Chpt 22
Table of Contents
I. Fertilization
1. Passage of female reproductive tract
Sperm mobility and penetration
2. Zygote formation
II. Pre-embryonic development
1. Implantation
2. Ectopic pregnancy
3. Placental hormones
4. Amnion
III. Embryonic Development
IV. Fetal development
1. Fetal Circulatory
V. Birth Defects
VI. Child Birth and Lactation
1. Stages of birth
2. Lactation
VII. Aging and Death
1. Decline of cell numbers and functions
2. Death
-The sperm and the egg of humans unite during fertilization. This usually takes place in the upper third of the uterine tube. Sperm is deposited in the vagina and it reaches the site of fertilization by swimming. Muscle contractions also aids in the wall of the uterine tube and uterus and it pushes the sperm on its way.
Sperm dissolve away the cells surrounding the oocyte and then they bore through the zona pellucida and the contact the plasma membrane. The first one to contact the membrane fertilizes the oocyte. Further sperm penetration is blocked. The chromosomes of the sperm and oocyte duplicate and merge in the center of the cell, where mitosis begins.
Human development is divided into three stages: pre-embryonic, embryonic, and fetal.
-During pre-embryonic development the zygote undergoes rapid cellular division forming a morula. The morula is then converted into a blastula, a structure with a hollow cavity, called a blastocyst in humans. The blastcyst consists of a clump of cells. The inner cell mass (ICM) becomes and embryo and the trophoblast gives rise to the embryonic portion of the placenta.
While the placenta is forming a layer of cells form the ICM of the blast cyst separates from it and forms an amnion. The amnion fills with fluid and enlarges during embryonic and fetal development, eventually surrounding the entire embryo and fetus protecting them during development.
-The ICM separates into three germ cell layers; ectoderm, mesoderm, and endoderm. The formation of the three primary germ layers marks the beginning of the embryonic development. The organs develop from these three primary tissues during organogenesis.
-Fetal development begins at 8 weeks after fertilization and is primarily a period of fetal growth because most of the organ systems have developed or are under development.
The placenta produces several hormones that play an important role in reproduction. HCG maintains the corpus luteum during pregnancy. Progesterone and estrogen stimulate uterine growth and the development of the glands and the ducts of the breasts. The placenta delivers oxygen and nutrients to the fetal blood nd removes waste products from it.
-The fetal circulatory system is very much like th adult circulatory system, except that it contains three pathways that allow blood to bypass the lungs and liver, which are developing but not functioning. At birth these bypasses close up and the adult pattern of circulation develops.
-Birth defects arise from chemical, biological, and physical agents. The effects of these agents is related to the time of exposure, the nature of the agent, and the dose. A defect is most likely to arise if a woman is exposed during an embryonic period when the organs are forming.
-Labor consists of intense and frequent uterine contractions believed to be caused by the release of small amounts of fetal oxytocin prior to birth. Fetal oxytocin stimulates the release of prostaglandins by the placenta. Oxytocin and prostaglandins stimulate contractions in the sensitized uterine musculature.
-Maternal osytocin is also released, augmenting muscle contractions. As uterine contractions increase, they cause more maternal oxytocin to be released, which stimulates stronger contractions and more oxytocin release, a positive feedback that continues until the baby is born. Labor consists of dilation, expulsion, and placental stages. The breast consist primarily of fat and connective tissue interspersed with milk-producing glandular tissue and ducts. During pregnancy, the glands and ducts proliferate under the influence of placental and ovarian estrogen and progesterone.
-Milk production is induced by maternal prolactin. Before milk begins, the breast produce a small quantities of a protein-rich fluid called colostrum. The baby usually consumes the fluid and it enriches their bodies as well as aiding in building up their immune system.
-Aging is a progressive deterioration of the body’s homeostatic abilities and the gradual deterioration of the function of the body’s organs. These changes result in at least two of the factors; a decrease in the number of cells in the organs and a decline in the function of existing cells. Death is the result.
Human Evolution
Chpt 23
Compendium review
I. The Evolution of Life
1. Chemical evolution
2. First cells and Eukaryotes
II. How Evolution Works
1. Natural Selection, Genetic Variation
III. Evidence Supporting Evolution
1. Fossils
2. Biochemical Similarities
IV. Early primate Evolution
V. Evolution of Australopithecines
VI. Evolution of Genes Homo
1. Human races
Scientists believe that the Earth and the sun and the rest of the system came from and enormous cloud of cosmic dust and gas that gave rise to the Earth and the sun. The Earth formed about 4.5 billion years ago.
-The evolution of life probably began in the sea and is divided into 3 phases: chemical evolution, cellular evolution, and the evolution of the multicultural organisms.
-Chemical evolutions scientists think that about 4 billion years ago. Simple inorganic chemicals that were dissolved in the seas combined to form small organic molecules. Over time, the organic molecules combine to form polymers, small proteins and nucleic acids. These polymers combined to from aggregates that may have been the precursors of cells.
-The first few cells arose from the primitive aggregates. They contained primitive enzymes and simple genes and may have derived nourishment from organic molecules they absorbed from the environment.
-Over time scientists believed that photosynthesis envolved further and the new photosynthetic organisms began to produce oxygen.
-Prokaryotes emerged in about 3.5 billion years ago. Eukaryotes evolved about 1.2 billion years ago. The evolution of the eukaryotes opened the door for the evolution of multicultural organisms.
-A variety of multicultural plants and animals evolved from the single celled eukaryotes in the oceans. The ozone layer developed and life on land became possible.
-Evolution has produced a great diversity of organisms. Evolution takes place because of the genetic variation and natural selection. Genetic variation in a species arises from many factors such as mutations and from new genetic combinations resulting from sexual reproduction. Genetic variations in traits that may offer some organisms an advantage over others, giving them a better chance of surviving, reproducing, and passing the genes on to future generations. Beneficial traits are preserved in a population by natural selection.
-The scientific knowledge in support of evolution is rich and varied. The fossil record, anatomical similarities in groups of organisms, the common biochemical makeup of organisms, similar embryological development among many groups of organisms. The experimental evidence all support the theory of evolution by natural selection.
-When talking about early primate evolution humans belong to this order. Primates are characterized by grasping hands, forward-looking eyes and large brains.
*Timeline*
Based on fossil evidence it appears that the primates evolved from a mammalian insectivore that resembled the modern-day tree shrew and lived about 80 million years ago. They think that humans evolved from early apelike creatures.
-The first human primate belonged to the genus Australopithecus. The oldest known skeleton was unearthed in Africa 3.5 million years old. It belongs to the group Australopithecus afarensis. It stood about 3 ft tall and its brain was just slightly bigger then an ape’s but they were thinking that it probably walked erect.
-3 million years ago A. afarensis was replaced by other species A. africanus which was slightly taller and it had even a bigger brain.
-2.3 million years ago A. robustus emerged. It was taller and heavier and had an even larger brain.
-2.2 million years ago the forth species emerged and it was called A. boisei.
-Many paleontologists believe that A. afarensis also gave rise to the genus Homo, and ancestors of the modern humans. Homo sapiens. Some people still think that it might had emerged from another ancestor all together. The earliest discovery of a human skull was 1.8 million years ago in Tanzania. It belonged to the homo habilis.
-200,000 years ago after the emergence of homo habilis the homo erectus arose. Homo erectus unlike it predecessors that remained in Africa these guys moved to Europe and Asia. They stood about 5 ft tall and used fire and many different kinds of tools but their brains smaller than ours and we are believed to have some from them directly.
-Homo sapiens emerged about 300,000 years ago and consisted of two subspecies: homo sapiens neanderthalensis and homo sapiens sapiens.
-The Neanderthals lived in caves and camps in Europe and Asia approximately 40,000 years ago. Some archaeologists believe that they were replaced by modern humans, the CroMagnons and earliest members of the homo sapiens sapiens. The Cro-magnons first appeared in Africa and then spread across Europe and Northern Asia and wiped out the Neanderthals or maybe even copulating with them.
-Other the course of many years, the human population moved and went far and wide. They inhabited many climate changes and became very good at adapting and overcoming the various complications that arose. With these travels the formation of different cultures began to form. Many adaptations that make up the different races are thought ot have happened due to the races and different population groups adapting to the environment.
Table of Contents
Ecology & the Environment
Chpt 24
I. Introduction to the Ecosystems
1. Biosphere
2. Biomes & Aquatic Life Zones
II. Ecosystem Function
1. Producers & Food Chains
2. Energy & Nutrient Flows
3. Trophic Levels
4. Nutrient Cycles
III. Overshooting the Earth’s Carrying Capacity
1. Polution
2. Resources
IV. Overpopulation: Problems and Solutions
V. Resource Depletion
1. Forest, Soil, & Water
VI. Pollution
1. Global Warming and its Impacts
2. Ozone layer
Humans survival is dependent on the resources that surround us today. It is vital to keep these resources available and not to exhaust them otherwise we could face extinction ourselves. Ecology is the study of ecosystems. It is the examination of organisms and their environment and many of the interactions between them. The living skin of the planet is called the biosphere. It goes from the bottoms of the oceans to the tippy top of the highest mountains. The only thing that is necessary for this process to take place is the addition of sunlight. Too much sun and heat can be detrimental to plants and animals as well as not enough sun. It is a proper balance between the environment and the dependency of sunlight.
-The biosphere is a closed system in which materials are recycled over and over again. I have heard this referred to as the circle of life. The Earth;s surface is divided into large biomes eah with a characteristic climate and characteristic to plant and animal life. The ocean is referred to as a biological region known as the aquatic life zones.
-The ecosystem consists of a community of organisms, its environments, and their interactions.A group of organisms with the same species living in a specific region constitutes a population. If you have two or more populations occupying a region it is called a community. The area that a species being human or animal is called a habitat. A Species’ niche is made up of its habitat and where they are on the ladder of the food chain.
-Virtually all life on Earth depends on plants and other producers, organisms that synthesize organic materials from sunlight, carry carbon dioxide, and water via photosynthesis. Organisms depending on producers for food are called consumers. Four types of consumers are present and they are herbivores, carnivores, omnivores, and detrivores.
-When talking about the food chain we are all a part of it.
The food chains begin at plants that are consumed by grazers (herbivores) and this is called the grazer food chain. Those that feed off of dead organisms or wastes are a part of the decomposer food chain. The position where an organism is located on the food chain is called the trophic level.
Nutrients are necessary for life growth and for life to flow through the nutrient cycles.
-The term secession refers to a series of changes in the ecosystem in which one community replaces another until a mature ecosystem is produced. Primary succession is where a community previously existed. Secondary succession occurs where a community was destroyed by natural or human events. I thought of Pompay.
-Although environmental problems vary from one nation to another they are all the result of human populations exceeding the carrying capacity of the environment. Carrying capacity is the number of organisms an ecosystem can support indefinitely and is determined by food and resource supplies and by the capacity of the environment to assimilate or destroy waste products of organisms.
Overpopulation occurs anytime a population exceeds it carrying capacity. This can be by looking at the food ratios available lack of resources, and excessive pollution. It can be all three or even one of the three that could be harmful.
-When talking huge numbers of population growth I think of Africa, Asia and Latin America. Resource shortages and food depletion are the main concerns or problems in this area. Many experts believe that industrialized areas are overpopulated . I thought of New York when immigrants were flooding the area and there were extreme pollutants and sickness due to the inhumane ways of discarding wastes and such. It was industrial and it suffered.
-Human population can be sumed up in 6 words; too many people, reproducing too rapidly, which results in resource shortages, excessive pollution, and poverty.
Resource depletion is a huge problem and concern. Humans use renewable and nonrenewable resources and all of which are depleting. Forest are being cut down faster then they can be replaced. That is why bamboo is a great option for building and such because it grows at a rapid rate. There are many things we can do to help in the environmental problems… GO green! Recycle, plant trees, soil conservation, population control, and drive energy efficient cars but there are many other stategies that need to be implemented in order for it to work or help! The soils are being eroded from rangeland and farmland. The effects of this will be food production later down the road. Many areas in the world suffer from water shortages. With the rise in population this will get far worse before it gets better. I saw on the news the other day about huge sin holes that were evident because of the underground streams being used and causing the ground to give out.
-Oil supplies are also finite. Global oil is expected to peak between the years of 2004 and 2010. Production may not be able to meet demand. An alternative to this catastrophy would be to use renewable fuels, and a sustainable energy supply.
-Pollution from human activities is overwhelming and it has a huge strain on the nutrient cycles and assisting is destroying homeostasis. One of the most serious threats of pollution is carbon dioxide. Carbon dioxide is a greenhouse gas that traps heat in the Earth's atmosphere. This increases the planet's surface temperature, altering this climate, shifting the rainfall patterns and agricultural zones, flooding low lying regions and destroying many species that cannot adapt to the sudden change in temperature. To slow the effects of global warming scientists recommend massive reforestation projects and dramatic improvements in the efficiency of the fossil-fuel combustion and development of alternative fuels. There are two gases that are the gaseous pollutants ans they are sulfur dioxide and nitrogent dioxide and they are released from power plants, factories, automobiles, and other sources.
-The ozone layer encircles the Earth, trapping unltraviolet light. It is being destroyed by CFC's and other pollutants.
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