Monday, July 21, 2008

unit 4 evaluation!

1. What were the three aspects of the assignments I've submitted that I am most proud of?
I am most proud of my 2 quizzes 100% on both! And my last compendium it took me FOREVER!!!!!
2. What two aspects of my submitted assignments do I believe could have used some improvement?
My lab project was not very impressive but I think I got all the desired information in it and my ethical issues essay was very short but again I made my point.
3. What do I believe my overall grade should be for this unit?
I worked really hard and I feel that I deserve a high b or low a


REGARDING THE UNIT (adapted from Stephen Brookfield, University of St. Thomas "Critical Incident Questionnaire")
At what moment during this unit did you feel most engaged with the course?
I felt most engaged learning about our effect on the earth. I feel obigated now to make less of a negative impact on the earth

At what moment unit did you feel most distanced from the course?
Honestly I was not very interested in the evolution section. Its just not my cup o tea
What action that anyone (teacher or student) took during this unit that find most affirming and helpful?
Once again being able to look at other students blogs is very helpful.
What action that anyone (teacher or student) took during this unit did you find most puzzling or confusing?
none

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 it is surprising how much the activity in America has affected our earth and ow little we have done to fix the situation
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ethical issue 4


In the world today it is a common concern about the strain of humans on the earth’s resources. What is causing this strain? Is it the high growth rate in lower developed countries or is it the high consumption rate in the more developed countries? Both of these cause a strain on the earth’s natural resources but it seems that in the more developed countries, the consumption rate is out of control. In America today we consume more than any other country with China trailing right behind. It seems that the lifestyle that we have become accustomed to is one of extreme waste and overexploitation of resources. We in America will drive around just for pleasure, spend an incredible amount of money on coffee drinks and fast food, and spend millions of dollars on frivolous items and many other methods of waste. It seems to me that those people living in less developed countries, barely using any water, fossil fuels or energy pose less of a threat to the environment than those of us in America carelessly wasting irreplaceable natural resources.
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In this lab project I will discuss species that I come in contact with on a regular basis and the relationship that I have with them
1. Humans- homo sapiens this relationship is symbiotic and we are domesticated.

2. Dog- canis lupus familiaris the relationship is mutualistic because we both benefit from the relationship and they are domesticated

3. Cat- felis catus. The relationship is again mutualistic because we both benefit from the relationship and most kinds of cats are domesticated
4. Mosquito- part of the family culicidae. The relationship is predator/prey type because they seek out blood from prey. They are not domesticated
5. Snake- part of the reptile suborder serpents. The relationship is predator/prey because they seek out prey and we are also their predators. They are not domesticated
6. Cow- of the family bovidae and the subfamily bovinae. Our relationship is commensal because we use them for food. They are domesticated.

http://www.chewingthecud.org/Grilled_Steak.jpg
7. Horse- equus caballus. Our relationship is mutualistic as well as symbiotic. We provide them food and shelter in return for transportation and companionship. Some are domesticated
8. Moth- insects of the order Lepidoptera. The relationship is symbiotic. They are not domesticated
9. Spider- invertebrate animals. The relationship is predator/prey they are predators on smaller insects and we are their predators. They are not domesticated.
10. Chicken- gallus gallus domesticus. The relationship we have is commensal. They are domesticated.


http://www.signs-up.com/prod_images/Chicken_xing_thumb_640.jpg/Chicken_xing_thumb_640.jpg
11. Bacteria- unicellular organisms that appear in groups. The relationship is parasitic. Some strains of bacteria are domesticated.
12. Fish- aquatic vertebrates. The relationship is commensal and symbiotic. They are not domesticated.
http://www.fishingtalks.com/images/salmon.jpg
13. Beetle- group of insects in the order of cleoptera. The relationship is symbiotic because beetles contribute to our ecosystem. They are not domesticated
14. Grains- a group of seeds used for food. The relationship is commensal. The species is domesticated
15. Frog- amphibian in the order anura. The relationship is symbiotic. They are not domesticated.

http://www.azootoyou.com/files/Giant_pixie_frog_best_04.jpg
16. Lizard- reptiles in the order squamata. The relationship is sometimes symbiotic and sometimes mutualistic. They are not domesticated
17. Lettuce-lactuca sativa. The relationship we have with lettuce is commensal. The species is domesticated.
18. Mold-microscopic fungi. The relationship is parasitic. Some variations of the species are domesticated.
19. Bird- vertebrates in the class of aves. The relationship is symbiotic. Some species are domesticated.

http://news.nationalgeographic.com/news/2006/10/images/061010-new-bird_big.jpg
20. Cricket- insect in the family gryllidae. Our relationship is symbiotic. Crickets play an important role in our ecosystem. They are not domesticated.
21. Butterfly- insect in the order Lepidoptera. The relationship is symbiotic. They are not domesticated.

http://twistedphysics.typepad.com/cocktail_party_physics/images/butterfly.jpg
22. Skunk- mammals in the family mephitidae. Our relationship is symbiotic. They are not domesticated.
23. Yeast- fungi the relationship is parasitic. Some strains are domesticated
24. Apple- malus domestica. The relationship is symbiotic. They are domesticated.
25. Ant- insect in the family formicidae. The relationship is symbiotic. They play an important role in the ecosystem. They are not domesticated
26. Bee-insects in the subfamily apoidea. The relationship is symbiotic. They are sometimes domesticated.

http://whyfiles.org/267bee_virus/images/bee.jpg
27. Turkey- bird in the genus meleagris. The relationship is commensal. They are domesticated
28. Ferret-mustela putorius furo. Te relationship is mutualistic. They are domesticated

http://www.freewebs.com/ferretwhisperer/White2020SaltPepper20Ferret.jpg
29. Goat- capra aegagrus hircus. The relationship is commensal. We rely on them for food production (milk)
30. Rose- flowering shrub of the genus rosa. The relationship is mutualistic. We enjoy them and we help them grow. They are domesticated.


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unit four lab 2



1. My high fertility rate counry was Congo with a fertility fate of 5.70.
2. My low fertility rate country was Barbados with a fertility rate of 1.80
3. The pyramid shape of the high fertility rate country represents that a major portion of the population has the ability to have children and are doing so at a high rate.
4. The oval shape of the low fertility rate country means that not as many people are reproducing and the groups of people are more even, not too many more children than adults and vise versa.
5. A situation with a lot of older people might be expected to be
quieter
slower paced
responsible
more money
clean
less technology
less waste
lower crime rate
lots of traveling
more home based activities
a situation with a lot more young people could be expected to be
louder
fast paced
negligent
wasting money
technologically advanced
more wasteful
high crime rate
laziness
content with surroundings
messy
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Compendium 8

This review will cover
1. The origin of life
2. Biological evolution and adaptation to environments
3. Ancestry of humans
4. Evolution of hominids and humans
5. Ecosystems
6. The flow of energy
7. Biogeochemical cycles
8. The human population
9. Use of natural resources and pollution
10. Biodiversity

1. The basic principle of life is that all living things are made of cells. All cells come from a pre-existing cell. Some believe that this process began as a chemical evolution. Taking this further, they believe that over billions of years the earth was probably formed from dust particles and debris. The solar system came at a later time. At first the earth was very hot due to hot gasses from volcanoes.
The earth then cooled because water that was first a gas then formed thick clouds causing rains over many years to become oceans. This early earth had sources of energy like volcanoes, meteorites, radioactive isotopes, lightning and UV radiation. The gasses may have then reacted with each other to form small organic compounds like nucleotides and amino acids. The small organic molecules may have joined to cause organic macromolecules. The following are two hypotheses about how this may have happened: the RNA first states that only the RNA was necessary to advance toward the first cell. The Protein first hypothesis states that amino acids collected in puddles and the sun’s intense heat initiated the formation of proteinoids. These proteinoids are then returned to water where they form microspheres (contain many of the properties of a cell but formed only of protein). Protocells are cells that can metabolize but cannot reproduce. Supporters of each hypothesis have their own conclusions about how the first true cell came into existence. RNA first supporters say that RNA specified protein synthesis which produced enzymes, one of these enzymes may have been one like reverse transcriptase used RNA to form DNA and then DNA replication happened as usual. Protein first supporters say that the protocell had some proteins that evolved the ability to synthesize DNA from nucleotides found in its surroundings. From there DNA could specify protein synthesis.
2. The first cells were probably prokaryotic cells which evolved into eukaryotic cells and from there formed fungi, plants and animals. The term biological evolution refers to the process of a species evolving over time. This means that all living things have a common chemistry and cellular structure. Another important aspect of biological evolution is adaptation (adjusting to better fit a specific environment). The theory of evolution was first thought of by 22 year old Charles Darwin in about 1831.



He used fossils as evidence for evolution because he believed they dated back to 10,000 to billions of years ago. Fossils are found in a wide variety from footprints to droppings to bones and impressions of plants. Much can be learned from the study of fossils.

Fossils are dated by the layer of stratum they are found in. The hard parts of organisms are what are preserved in fossils such as teeth and bones. Mineralization is the process by which these parts are preserved. Paleontology is the study of life in prehistoric times using evidence in fossils. The fossil record is the recorded history as seen through fossils, this record is the most conclusive proof that evolution has occurred. Transitional fossils are those that show characteristics of two different groups, therefore sowing who is related to whom. The theory of evolution is also supported by biogeographical evidence, which is the placement of plants and animals in different parts of the world. This supports the hypothesis that life forms evolved in a particular location and then spread out throughout the world. Anatomical evidence is anatomical similarities between organisms’ shows a common decent. Homologous structures are similar because they share a common ancestor. Analogous structures do not share the same ancestry but do serve the same function. Vestigial structures are features that are developed in some creatures but serve no purpose in other creatures. Biochemical evidence shows that almost all living organisms use the same basic biochemical molecules (DNA, ATP and enzymes) and some of these genes are shared from worms to humans. Natural selection is a mechanism for adaptation which has two critical elements and an adaptation is the result. The first element is variation- the physical variations between different members of a species. The second element is competition for limited resources. The members of a species with advantageous traits reproduce and others die off. This theory is also known as survival of the fittest.
3. Humans are classified by their evolutionary relatedness. Binomial names refer to the names that give the genus and species. Primates are placental mammals that have adapted to living in trees. Humans are in this classification of mammals. Prosimians include lemurs, tarsiers, and lorises and anthropoids include monkeys, apes and humans. Primates have mobile limbs and sometimes an opposable thumb and big toe, binocular vision, a large complex brain and a reduced reproduction rate. The genomes of humans and chimpanzees are 99% identical but that one percent difference accounts for the number of differences between chimpanzees and humans.
4. Our branch of the evolutionary tree is known as the hominid branch. The features of a hominid include walking on two feet, the shape of the face and the size of the brain. Human features evolved gradually and at an unequal rate. An incorrect assumption is that humans evolved from apes, we are actually more like distant cousins to the ape. Fossils have been found that seem to be from the time of the ape/human lineage split, these fossils are known as Sahelanthropus tchadensis. This fossil was found in central Africa. Other fossils of early hominids have been found in eastern Africa. It seems that the hominids decent began with australopithecines which evolved and diversified in Africa. Some of them were short and slender and known as gracile and others were more powerful and had larger upper bodies and were termed robust. One fossil in particular found in eastern Africa was found over 20 years ago by a team led by Donald Johanson. This fossil had a smaller brain, but walked bipedally.

The term homo is given to a fossil of the brain size is large enough, the jaw and teeth resemble those of humans and the use of tools is evident. Early homo is termed Homo habilis. It had a large brain and cheek and teeth structures that indicate being omnivorous. They also made tools out of stone. The part of the brain that is associated with speech is enlarged, indicating that they could hunt cooperatively. Homo erectus fossils have been found in Africa, Asia, and Europe. There are different species associated with the name Homo erectus. Homo erectus in comparison to Homo habilis has a larger brain and a flatter face with a projecting nose. They were taller, stood erect and were very muscular. Homo erectus used fire and advanced tools. It is believed that Homo sapiens most likely evolved from Homo erectus in several different regions of the world including Asia, Africa and Europe. Neandertals were first discovered in Germany. The brain of the neandertal was larger than that of the Homo sapiens. They show signs of being culturally advanced such as building houses, using stone tools, controlling fire, and buried their dead with flowers and possibly had a religion. Cro-Magnons are designated as Homo sapiens. Their DNA is different from neandertal DNA and therefore it is believed that they did not interbreed. They made more advanced stone tools, possibly were the first to throw spears; they may have even had a language and lived in small groups and their culture included art. It is believed that human variations arose from adaptations to a particular environment some of these that we can see today are skin color, body shape, hair texture and shape of the lips.

http://www.scienceclarified.com/images/uesc_06_img0297.jpg
5. The term ecosystem is given to a place where organisms interact among themselves and with the physical and chemical environment. These interactions between organisms keep the ecosystem intact and therefore the biosphere. There are a few different classifications of ecosystems referred to by scientists; temperate forests, deserts, tropical grasslands, tropical rainforests, temperate grasslands, taiga and tundra are the major classifications of terrestrial ecosystems. Aquatic ecosystems are composed of those that have fresh water and those that have salt water. There are two freshwater ecosystems, those with standing water (lakes and ponds) and those with running water (rivers and streams). Saltwater ecosystems include marshes which are where rivers meet the ocean and coral reefs are off the shore. Ecosystems include abiotic and biotic components (living and nonliving) and are categorized according to their food source. Autotrophs are producers that only require inorganic nutrients and an outside energy source for survival. Heterotrophs require organic nutrients for survival and are therefore the consumers of an ecosystem. Classifications of Heterotrophs are herbivores that eat only plants and algae, carnivores eat only other animals and insects, omnivores eat both plants and animals and detritus feeders eat decomposing particles of organic matter. A particular organism’s role in an ecosystem is known as its niche. All ecosystems are characterized by its energy flow and chemical cycling. Energy flow is the process of the producers of the ecosystem absorbing energy from the sun and chemical cycling is the producers taking inorganic nutrients from the environment. The producers then make organic nutrients for themselves and other populations of the ecosystem.

http://www.visitandlearn.co.uk/topicalfactfiles/images/ecosystems2.gif
6. The flow of energy is represented by a food web and there are different types of food webs such as a grazing food web and a detrital food web. A food chain is a diagram that shows a single path of energy flow. Within a food chain are different trophic levels (all the organisms that feed on a particular link in the chain) food chains are relatively short due to the loss of energy between the trophic levels. The loss of energy is very significant only about 10% of the energy available to one trophic level is available to the next level.

http://www.jenningsk12.net/WE/peimann/Science/FoodChains/food_chain.jpe
7. All organisms in an ecosystem require organic and inorganic nutrients. Chemicals circulating through the ecosystem create a biogeochemical cycle. These cycles can be gaseous or sedimentary. One of these cycles is the water cycle which begins with water evaporating from the ocean and net condensation occurs meaning that a gas is changed to a liquid. The water that has evaporated from the ocean condenses and then falls back to the earth as precipitation. Water can also be evaporated from the land and plants the water that is on the land is eventually returned to the sea by the process of runoff. Some precipitation does not runoff back into the ocean but seeps into the earth to a certain level. Aquifers are a layer of permeable rock, sand, or gravel through which ground water flows and they contain water that supplies wells and springs. Human activities can greatly affect the water cycle in three ways 1. Taking water from aquifers 2. Clear vegetation from the land and build roads which in turn prevent water from seeping into the ground 3. We add pollutants to water through sewage and chemicals we use. The carbon cycle is a biogeochemical cycle where the atmosphere serves as the exchange pool. On land plants take up carbon dioxide then the organisms respire releasing carbon into the atmosphere as carbon dioxide. In an aquatic ecosystem carbon dioxide combines with water to produce bicarbonate ion. The bicarbonate in the water is in equilibrium with the carbon dioxide in the air. Dead and living organisms hold organic carbon and are reservoirs for the carbon cycle. Due to human activities more carbon dioxide is being released into the atmosphere than is being removed. This is unfortunately contributing to the global warming trend we are seeing. Another biogeochemical cycle is the nitrogen cycle. Nitrogen makes up about 78% of the atmosphere. In the nitrogen cycle, nitrogen gas is converted to ammonium which plants can utilize. Plants use nitrates as a source of nitrogen. The process of producing nitrates during the nitrogen cycle is called nitrification, this process happens in different ways; Nitrogen gas is converted to nitrate in the atmosphere, ammonium is converted to nitrate by soil bacteria, nitrate-producing bacteria convert ammonium to nitrate, nitrate producing bacteria convert nitrite to nitrate, plants take up ammonia and nitrate and produce proteins and nucleic acids. Dentrification is the process of turning nitrate back to nitrogen gas. The phosphorous cycle is another biogeochemical cycle where phosphorous is trapped in the ocean and then released onto the land where plants use it, and then animals eat the plants and turn the phosphate into teeth, bones and shells, death and decomposition of the animals and their teeth and bones once again makes phosphate available to the producers.
8. The population of the world has now grown to about 7 billion people. The world is currently experiencing a time of exponential growth meaning that it is steadily increasing. About 78 million people are added to the world each year. The term growth rate refers to the difference between the amount of people born and the amount of people that die per year. The maximum growth rate under ideal conditions in the world is known as the biotic potential. The carrying capacity of the environment is called the carrying capacity. Two classifications of countries in the world today are the more developed countries (MDC’s) and the less developed countries (LDC’s). More developed countries have a lower population increase rate while in the LDC’s the population continues to rise steadily.



http://www.sustainablescale.org/images/uploaded/Population/World%20Population%20Growth%20to%202050.JPG
9. Humans have needs that are fulfilled by resources, resources can be classified into renewable, which can be replenished and non renewable, which are irreplaceable and limited in supply. One of the resources humans need is land, we need land to live on, farm on and for a variety of other buildings. Humans living on and using land for crops and other uses can have detrimental effects on the land making it difficult or impossible to use in the future. Water is a resource that should be available to all humans, but the overuse of freshwater for the irrigation of crops deems it almost impossible for water poor areas of the world to have adequate water. The use of dams and aquifers are two ways humans increase the freshwater supply, both of these definitely have adverse effects on the earth. The increase in the supply of food in the last 50 years has come along with these harmful practices; planting crops with few variations which will eventually deem the land unusable for future crops, use of fertilizers pesticides and herbicides which have negative effects on the earth and those that consume them, irrigation which wastes a copious amount of water and finally overuse of fuel for production of these foods. There are both renewable and non renewable energy sources non renewable energy resources are fossil fuels oil, natural gas and coal. The use of these fuels unfortunately contributes to global warming. Renewable energy sources are hydropower, geothermal, wind and solar energy which are all better for the environment than the fossil fuels. Minerals are those non renewable resources that can be extracted (mined) and then used by humans in a variety of ways.
10. There is variety to life on earth and this is known as biodiversity. Many factors are contributing to the loss of biodiversity in the form of extinction including loss of habitat, alien species, pollution, overexploitation, and disease. There are many benefits to maintaining biodiversity including medicinal value because many medicines come from living organisms. Agricultural value comes from maintaining a diverse group of crops in the world. Another important aspect of biodiversity is human consumption, keeping a consumable amount of animals and fish will greatly benefit the human population. There are indirect values of maintaining biodiversity as well these are waste disposal by means of decomposers breaking down dead organic matter for use by producers in an ecosystem. Provision of freshwater is another indirect value of maintaining biodiversity, many organisms need freshwater for survival and maintaining our supply of freshwater will be invaluable. The prevention of soil erosion, biogeochemical cycles, climate, and ecotourism will also benefit the biodiversity of the earth. In today’s word it is important to make the smallest ecological footprint possible and thereby maintaining a sustainable society. Especially in America we need to focus on saving our earth for future generations by consuming less water, energy, food, and other natural resources while creating as little waste as possible.
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Thursday, July 17, 2008

Lab Project Fetal Development

In this lab I will discuss 11 events that I think are crucial to pregnancy and the developing baby and why I feel that these events are important.
1. Fertilization of the egg- This is the most important event because it is the beginning of the pregnancy journey.
2. Implantation of the embryo into the uterus wall- this is very important because correct placement of the embryo can mean a successful pregnancy but incorrect placement of the embryo into the fallopian tube can result in a failed pregnancy. This begins one week after fertilization and ends about two weeks after fertilization
3. Hormone levels increasing- The hormone levels in a pregnancy are very important for many reasons the hormone hCG (human chorionic gonadotropin) supports the pregnancy by ensuring production of progesterone until the placenta is fully formed. This is also the hormone that is detected on pregnancy tests. Progesterone is produced by the placenta and it functions to inhibit contracting of the uterus by inhibiting smooth muscle. This affect on smooth muscle also shows in other areas of smooth muscle in the woman’s body. Estrogen is also produced by the placenta and it is characterized by an increase in uterine blood flow and a woman’s increased emotional sensitivity. Pro-lactin is another hormone that allows for lactation postpartum. These hormone levels begin changing when the embryo implants and do not stop fluctuating until after the baby is born
4. Formation of what will become the amniotic cavity- significant because this is what will surround and protect the baby from activity by the mother and it begins at 7-12 days after fertilization
. Formation of future placenta and umbilical cord- important because this is what will nourish the baby for development and rid it of wastes. The umbilical cord will serve as a blood exchange route. This begins at about 13 days after fertilization
6. The beginning of gastrulation- significant because the cells migrate to areas to become tissue layers known as the primary germ layers and are called the ectoderm which becomes the skin, lining of oral cavity and the nervous system. The mesoderm becomes the skeleton, muscular system, dermis of skin, cardiovascular system, reproductive system and digestive system among others. The endoderm becomes the lining of the digestive and respiratory tract and other glands associated with these systems. This happens at 13-16 days after fertilization
7. The heart starts to beat- significant because it shows that this is a human being even at this early stage of development. Occurs at 23-25 days after fertilization

8. Formation of future brain and spinal cord- both crucial to development and life of the baby. Begins at 17-19 days after fertilization
9. Limb bud formation- this is the beginning of the embryo looking more like a human being. Begins at 31-35 days after conception
10. The pituitary gland starts forming- significant because this gland will eventually send the message to the uterus to start contracting. Begins at 42-44 days
11. Formation of the gonads- significant because these will soon begin to show outward signs of the sex of the baby! Begins at 48-51 days


There are so many important events in a pregnancy it is difficult to narrow it down to ten, I feel that the most crucial development happens in the first trimester so I kept my events narrowed down to those months.
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Wednesday, July 16, 2008

compendium 7

This review will cover
1. The male reproductive system
2. The female reproductive system
3. The female monthly cycle
4. Reproduction control
5. STD’s
6. Fertilization through embryonic development
7. Fetal development
8. Birth
9. Development after birth

1. Included in the male reproductive system are the testes, epididymides, vasa deferentia, seminal vesicles, prostate gland, urethra, bulbourethral glands and the penis. Sperm are produced in the testes and continue maturation in the epididymis. Mature sperm leave the epididymis and are stored in the vas deferens. The vas deferens drain into the ejaculatory duct which enters into the urethra. As seminal fluid is passed through the seminal vesicles, prostate gland, and bulbourethral glands, secretions are added to them and the liquid becomes what is known as semen that is excreted upon ejaculation. At the tip of the male penis is a swelling called the glans penis which at birth is covered by a layer of skin which is sometimes removed soon after birth. Nitric oxide is released during sexual arousal which allows for the release of cyclic guanosine monophosphate which allows for the erectile tissue to fill with blood thus becoming erect. In the time of an erection a sphincter cuts off the entrance from the bladder into the urethra so that no urine can enter. Semen enters the urethra after sexual arousal and contractions of the muscles in the penis push the semen out in spurts. Typically there is 3.5 ml of semen in one ejaculation and up to 400 million sperm in that 3.5 ml. the scrotum holds the testes a distance away from the body to allow for a lower temperature for the sperm to thrive in. if the temperature is too high, the sperm do not function properly. In the testes are seminiferous tubules which are the areas where sperm are produced. The production of sperm is done in the meiosis process which was discussed in an earlier chapter. A mature sperm is composed of three parts a head, middle piece and a tail. Movement of the tail is made possible by the energy producing mitochondria in the middle piece. In the head there are enzymes that are necessary to break through the egg during fertilization. Testosterone, the most important of the male sex hormones is secreted by the interstitial cells that lie between the seminiferous tubules. The hypothalamus regulates the secretion of the hormones that control production of sperm and testosterone. Testosterone brings about the changes in a mole during puberty such as broader shoulders, lower voice and hair on face, chest and back.


http://www.faqs.org/health/images/uchr_02_img0144.jpg

2. The female reproductive system includes the ovaries, oviducts, uterus, cervix, and vagina along with various other organs. The ovaries are responsible for the production of eggs, estrogen and progesterone. The fallopian tubes are also known as the oviducts and they sweep the egg that has been expelled from the ovary into the tube. The egg moved down the tube toward the uterus. The uterus is the middle organ between the fallopian tubes and it ends with the cervix. The cervix opens into the vagina which is a canal for birth, allows for menstrual flow and is the sex organ in females. There are also external genitals on the female that are collectively known as the vulva. Upon sexual arousal some of the sexual organs become engorged with blood and lubrication seeps into the vagina.

3. The ovarian cycle has 6 stages first the primary follicle which contains an oocyte begins producing estrogen, and then the secondary follicle containing an oocyte also produces estrogen and progesterone. Third the vesicular follicle develops followed by ovulation. The fifth stage is when the oocyte has left the follicle; the follicle becomes a corpus luteum, which if unfertilized, will disintegrate. Estrogen is responsible for secondary sex characteristics in females such as fat distribution and hair growth. Later in a woman’s life the follicles slowly stop producing estrogen and progesterone ceasing the menstrual cycle, this change is known as menopause. These two hormones are also responsible for a series of events known as the uterine cycle. This cycle is divided by days. Days 1-5 the levels of the hormones cause blood vessels to rupture causing blood to seep from the vagina in a menstrual period. Days 6-13 there is a high production level of estrogen causes the endometrium to thicken. On day 14 ovulation typically occurs. days 15-28 production of progesterone increases and causes the endometrium of the uterus to increase in size and secrete a thick mucus preparing for implantation. If fertilization does not happen, the cycles begin again.
4. Regulation of the amount of children a person or a couple has is done in a variety of ways including the family planning method which has an 80% effectiveness rate, women’ s hormonal birth control which has between a 98% -99% effectiveness rate. The male condom has an 89% effectiveness rate. A diaphragm has a 90% effectiveness rate when used with a spermacide. IUD’s have a 99% effectiveness rate and contraceptive injections also have a 99% effectiveness rate. There is also a method of birth control used after intercourse to prevent fertilization, this is known as the morning after pill and has about an 80% effectiveness rate. Of all the birth control methods abstinence is obviously the safest and most effective in not only birth control but also STD protection.
5. Sexually transmitted diseases are caused by various factors including viruses, bacteria, protists, fungi and animals. STD’s caused by viruses include HIV which causes AIDS, genital warts, genital herpes, ad hepatitis. Of these STD’s there are only effective treatments for HIV/AIDS and genital herpes. Unfortunately though these are only treatments for the symptoms and do not cure the diseases. STD’s caused by bacteria are treatable and curable by use of antibiotics. These STD’s include Chlamydia, Gonorrhea, and syphilis. STD rates in America ire rising steadily and it is estimated that more than half of all people will have an STD at one time. (http://www.ashastd.org/learn/learn_statistics.cfm)
6. Sperm have long tails which allow them to swim toward the egg, once at the egg the head of the sperm releases a special enzyme that allows it to penetrate the egg then the sperm nucleus enters the egg and unites with the egg pronucleus and this is called fertilization. At this point the fertilized egg is known as a zygote. The zygote becomes an embryo and then a fetus. Lying outside the embryo and fetus are the extrambryonic membranes which are the chorion provides the fetus with nutrients and oxygen, the allantois protrudes from the embryo and collects the small amount of urine excreted form the fetal kidneys and will eventually form the bladder. The yolk sac is the first site of blood cell formation. The amnion contains fluid to cushion and protect the fetus during development. The gestation period is the 280 day period of time from the day of the start of the last menstruation to the day the baby is expected to be born. Pre-embryonic development is the first week of development beginning with fertilization of the egg followed by repeated division of cells while traveling down the oviduct to the uterus. A compact group of cells known as the morula becomes the blastocyst that arranges itself on a manner of an inner grouping of cells and an outer layer of cells. All the inner cells have the ability to develop into any type of tissue and will collectively become the embryo. Embryonic development begins in the second week and continues through the second month. During this time the embryo implants into the wall of the uterus and secretes the hormone human chorionic gonadotropin which is the hormone that is detected in pregnancy tests. In this week the inner cells become the embryonic disk and the yolk sac and the amniotic cavity form. During the third week of development the nervous system and the heart begin to develop. In the fourth and fifth weeks the umbilical cord develops and arms and legs develop from the limb buds. In the fifth week the head enlarges and the eyes ears and nose become visible. In the sixth through eighth weeks the form of the embryo begins to look more like a human being, the neck region develops and the nervous system is working enough to respond to stimuli. During the seventh week of development the gonads form and at this stage of development the male and female gonads look alike.
http://www.sciencehelpdesk.com/img/bg3_4/EmbryonicDevelopmentComplete1.gif
7. The umbilical cord is the path of the fetal blood between the fetus and the placenta so that blood between the mother and child is rarely exchanged. During the third month the gender of the fetus can be distinguished, the head is large in proportion to the rest of the body. Also during the third and fourth months the cartilage begins to be replaced by bone and the baby’s heartbeat is easily distinguishable. In months five through seven the mother can feel the baby move and the baby’s eyelids are fully open. At the end of the seventh month the baby is about 12 inches long and weighs about 3 pounds. In the eighth through ninth months development finishes and the baby’s lungs further develop and he/she gains weight needed to survive outside the womb.
8. There are three stages of labor, in stage one contractions pull the cervix up toward the baby’s head making the cervix virtually disappear, the water breaks and when the cervix is dialated completely the second stage begins. In stage two, contractions are about 1-2 minutes apart and last for 1 minute, the urge to push is becoming greater as the baby’s head lowers into the vagina. Once the head is delivered the rest of the body follows easily. In the third stage the placenta is delivered and the labor is complete.
9. Growth continues after birth in a sense all the way until death. As a person ages their body begins to show the signs such as the loss of skin elasticity, loss of movement in the joints, the cardiovascular system also suffers some signs of aging. Bone loss is also common later in life and many individuals suffer from osteoporosis. Tooth decay is also common in older individuals, but it is possible to prevent this with regular brushing and cleanings. It is inevitable that all humans will age and pass away, however it is possible to create a smooth transition by eating a healthy diet, exercising regularly and generally taking care of your body.
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