Unit Evaluation

REGARDING YOUR OWN PERFORMANCE
1. What were the three aspects of the assignments I've submitted that I am most proud of?
I was most proud of the fetal development lab, species lab, and my topic one review
2. What two aspects of my submitted assignments do I believe could have used some improvement?
The topic two review- alot of information was condensed, and the topic two review
3. What do I believe my overall grade should be for this unit?
I still this was solid work deserving of an A
4. How could I perform better in the next unit?
There is no next unit, but I feel that I have improved throughout this class and this has been one of the most beneficial classes I have taken so far

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?
Doing the species lab- was fun and interesting looking everything up ans really taking the time to think how we interact and effect other organisms every day
At what moment unit did you feel most distanced from the course?
During the reviews

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.)
The most surprising was all the facts of how resources are consumed compared to other countries, all the different organisms we interact with each each day, and how everything in this world started and continues to work together.

Unit 4 Ethical Issue- World Resource Use

World Resource Use

It is a known fact that the population today is using more and more natural resources with no real focus on how to conserve them in the future. There are groups of people who work very hard on this issue to try to come up with solutions, but in reality, I still think the majority of the population takes it for granted what we have now and puts this issue on the backburner for issues in the future.
Population growth by itself has some effect on straining resources, but when you add in the economical development and really look at how much resources one single individual uses, it is eye opening. When you have facts showing the relationship of one U.S. child consuming the same resources as 300 children in Ethiopia, this is an enormous difference. Again, I think alot of this consumption comes from the fact that many things are taken for granted here in the U.S. that populations over in third world countries don't have (cars for transportaion everywhere causing pollution, huge factories that make just about everything, clean supply of drinking water, more than adaquate food source, and many other extra luxeries- just look at all of the professional sports players and movie stars with at least two or more million dollar homes and 10 different vehicles, ect.). I'm not saying that I think everyone should live in poverty, but I do feel that people need to be more aware of what they are doing and should do everything possible to help conserve our current resources (carpooling, recycling, not being lazy and littering everywhere, ect. ect. ) Also if we can help third world countries get to higher level of living then things might balance out a little and they would not be having such a high fertility rate (along with high infant death rate), and this would eventually lead to a more steady growth instead of exteme increases.
There is no quick or easy solution to the problem at hand, but I believe that awarness is a step in the right direction. The bottom line is this world is only going to be able to support so much if we just keep taking and taking and do nothing in return to try to preserve or keep the natural order of our environment.

Unit 4 Lab Project

List of Species

1. Bacteria in Yogurt- Streptococcus salivarius, Lactobacillus delbrueckii : Symbiotic relationship and is domesticated


2. Corn in Cereal-Zea mays : Mutualism and domesticated to be harvested and mass produced


3. Wheat in Cereal-Triticum: Mutualism and domesticated to be harvested and mass produced


4. South African Cichlids- Astronotus ocellatus: Mutualism and domesticated


5. Beta Fish-B. splendens: Mutualism and domesticated


6. Red Belly Pacu-Colossoma brachypomum: Mutualism and domesticated


7. Red Devil-Amphilrophus citrinellus: Mutualism and domesticated


8. Great Danes-Canis lupus familiaris: Mutualism and domesticated, once used as hunting dogs and now are great pets and companions


9. Water Dragon-Physignathus cocincinus: Mutualism and domesticated


10. Crickets-Gryllidae: Predation (given to other animals for food) and domesticated to be mass produced for sale as food


11. Mealworms-Tenebrio molitor: Predation (given as food) and domesticated to be mass produced and genetically altered to be sold as food


12. Guinea Pigs-Cavia porcellus: Mutualism and domesticated once was used mainly as livestock and food, and now have become pets


13. Horse- Equus Caballus: Mutualism and domesticated


14. Lady Bugs in Garden-Coccinellidae: Symbiotic, possibly domesticated because we now raise them and sell them in large quantities for people's gardens, but still occur naturally in the wild


15. Butterflies in Garden-Ellepsaria lineolata: Symbiotic, partly domesticated because we produce and sell them, but they also occur naturally


16. Hummingbirds in Garden-Selasphorus rufus: Symbiotic, not domesticated


17. Daddy Long Legs-Pholcus phalangioides : Commensal (they do not harm me, but benefit from living in the house), not domesticated


18. House Fly-Musca domestica: Predation, not domesticated


19. Alfalfa Hay-Medicago sativa: Mutualism, domesticated to be produced and harvested


20. Timothy Hay-Phleum pratense: Mutualism, domesticated to be produced and harvested


21. House Plants- Sansevieria trifasciata: Mutualism domesticated


22. Bamboo-Bambusoideae: Mutualism, domesticated


23. Aloe Vera-Aloe succotrina : Mutualism, domesticated


24. Roomates- Homo sapians: In my case Symbiotic


25. Dust mites-Dermatophagoides farinas:In my case commensal (they benefit, and I have no adverse affects from them such as asthma or allergies), not domesticated

Works Cited

Frolich powerpoint

Wikipedia Encyclopedia

Unit 4 Demographics Online Lab

Demographics Lab

1. My high fertility rate country was Africa with a fertility rate of 5.90


2. My low fertility rate country was the Bahamas with a rate of 2.20


3.A high fertility rate means more people are being born each year then are dying so this results in higher numbers in the lower age groups. This affects future population growth because this large group of children will enter reproductive age around the same time and there will be more people entering reproduction age groups then leaving them


4.Lower fertility rates lead to more middle aged populations because you have a more even balance of people being born and death rate and also more even amounts of the population are leaving the reproduction years as more are entering it


5. Older aged population-

• retirement communities
• fewer schools
• more relaxed
• more assited care homes

Younger aged (more children)-

• more schools
• lower income housing
• busy
• high traffic
• positive attitude

Compendium Review Untit 4 Topic 2

Table of Contents

Human Evolution

• Origin of Life
• Biological Evolution
• Classification of Humans
• Evolution of Hominids
• Evolution of Humans

Global Ecology and Human Interferences

• The Nature of Ecosystems
• Energy Flow
• Global Biogeochemical Cycles

Human Population, Planetary Resources, and Conservation

• Human Population Growth
• Human Use of Resources and Pollution
• Biodiversity
• Working Toward a Sustainable Society

Human Evolution

Origin of Life

One fundamental principle of biology states "all living things are made of cells and every cell comes from a preexisting cell" It is believed that the sun and planets were formed over 10 billion years from dust particles. The first atmosphere was formed from gases escaping volcanos. As Earth cooled, the vapors condensed to liquid water and rained in enormous quantities making the oceans. The rain washed N2 and CO2 into the oceans. Energy was in the form of volcanoes, meteorites, radioactive isotopes, lightning and ultraviolet radiation. With all this energy these gases may have reacted together to form organic compounds such as nucleotides and amino acids. These small molecules would join to form macromolecules. There are two hypothesis one is the RNA-first hypothesis and the second is the protein-first hypothesis that result in the formation of microspheres. A true cell can reproduce and today this is done by DNA and cell division

Biological Evolution

The first true cells were prokaryotic and lacking a nucleus. Later eukaryotic cells with a nucleus evolved, then multicellularity. Biological evolution is the process by which a species changes over time. Two aspects are decent from a common ancestor and adaptation to the environment. Adaptation is why there is diversity of life and different types of living things. Natural selection is a mechanism for adaptation. Charles Darwin first formulated the theory of evolution. The evidence used to convince him of common descent were

1. Fossils- actual remains of species that lived at least 10,000 years ago
2. Biogeographical- study of the distribution of plants and animals in different places throughout the world
3. Anatomical- common descent offers explanation for anatomical similarities between different organisms

Evolution is a scientific theory based on evidence collected in a number of different fields. The natural selection process has three critical elements

1. Variation- individuals of a species have varying characteristics that can be passed on to generations
2. Competition for limited resources- limited resources results in unequal reproduction among members of a population
3. Adaptation-members with advantageous traits capture more resources and are liklier to reproduce and pass those traits on.

Classification of Humans

The binomial name gives the genus and species. Organisms in the same domain have only general characteristics in common, if in the same genus they have specific characteristics in common. Today major decisions regarding the history of life are being made using DNA, rRNA and protein sequencing data.

Humans are primates in the anthropoids group. Primates are adapted for tree living and have mobile limbs, grasping hands, flattened face, binocular vision, complex brain, and a reduced reproduction rate. Hands and feet have 5 digits each some with opposable thumbs.

Evolution of Hominids

By studying the characteristics of a group of organisms biologists construct and evolutionary tree that becomes a working hypothesis of their past history. Hominid refers to our branch of the evolutionary tree. When two lines of descent (lineage) first diverge from a common ancestor, the genes and the lineages are nearly identical. Paleontologists use anatomical features when they determine if a fossil is hominid such as bipedal posture, the shape of the face and brain size.

Evolution of Humans

Fossils are put in the genus Homo is the brain size is at least 600cm cubed, the jaw and teeth resemble those of humans, and tool use is evident. Homo habilis, dated approx 1.9 mya may have been the ones to start culture, possibly started by hunting cooperatively. Culture emcompasses human behavior and products and depends on the capacity to speak and transmit knowledge. H. erectus was the first hominid to use fire and fashion more advanced tools for cutting and scraping.

The majority of researchers believe H. sapians evolved from H. erectus. Multiregional continuity hypothesis believes H. sapians evolved in several different locations (Asia, Africa, and Europe). Out-of-Africa hypothisis believes H.sapians evolved from H. erectus, but only in Africa and then migrated. Since humans have evolved they have been widely distributed about the globe. Phenotypic and genotypic variations are noticable between populations, today this is know as ethnicities.

Global Ecology and Human Interferences

The Nature of Ecosystems

The biosphere is where organisms are found on Earth (fromt the atmosphere to the oceans). An ecosystem is where organisms interact among themselves and with the physical and chemical environment. Distinctive types of terrestrial ecosystems are known as biomes. Temperature and rainfall define these biomes containing communities of organisms that have adapted to the regional climate. There is the tropical rainforest, savanna, temperate grasslands, forests, deserts, taiga, tundra. Aquatice ecosystems are divided by fresh water(standing or running) and salt water (marine)

Abiotic components of an ecosystem are non living and biotic are living and are classified by their food source.

1. Autotrophs- require only inorganic nutrients and produce organic nutrients for themselve and others
2. Heterotrophs- need organic nutrients. They are consumers. Made up of herbivores, carnivores and omnivores.

A niche is the role of an organism in an ecosystem- how it gets food, how it eats that food, and how it interacts with other populations in the same community.

Energy Flow

A trophic level is composed of all organisms that feed at a particular link in a food chain .Only about 10% of the energy of one trophic level is available to the next trophic level. This flow of energy between trophic levels is shown as an ecological pyramid.

Global Biogeochemical Cycles

All organisms require a variety of organic and/or inorganic nutrients. The pathways by which chemicals circulate through ecosystems involve both living and nonliving components and are known as biogeochemical cycles. These can be gaseous or sedimentary. A reservoir is a source unavailable to producers. An exchange pool is a source where organisms take chemicals, that have moved there through the food chain. Human activities remove chemicals from the resovoirs and exchange pools and make them available to the community. This upsets the normal balance of nutrients for producers in the environment and causes pollution.

1. Water Cycle- humans interfere by withdrawing water from aquifers, clearing vegetation to build roads that increases runoff and interfere with natural purification and instead add pollutants to water
2. Carbon Cycle-by burning fossil fuels more carbon is added to the air, and also forests are being destroyed
3. Nitrogen Cycle- humans double the fixation rate by producing fertilizers from N2
4. Phosphorus Cycle-overenrichment of waterways is due to mining, runoff and livestock wastes

Human Population, Planetary Resources, and Conservation

Human Population Growth

The present population is about 7 billion people, and undergoing exponential growth. Growth rate is determined by the difference between the number of people born per year and the number who die per year. Biotic potential is the maximum growth rate under ideal conditions. Carrying capacity is the maximum population that the environment can support for an indefinite period. Today there are two groups the more developed countries- show modest population growth and have a good standard of living and then the less developed countries- exhibit dramatic population growth and generally live in poverty.

There are three age groups in populations: Pre-reproductive, reproductive, and postreproductive. The LCDs are experiencing growth because they have more women entering reproductive years then leaving them.

Human Use of Resources and Pollution

Humans have basic needs and a resource is anything from the biotic or abiotic environment that can help meet these needs. Nonrenewable resources are limited in supply (land, fossil fuels, minerals). Renewable resources can be naturally replenished (solar energy, harvesting plants and animals for food). Pollution is any alteration of the environment in an undesirable way. (Desertification, deforestation, dams, aquifiers, subsidence, saltwater intrusion)

Biodiversity

This is the variety of life on earth which is described in terms of number of different species. Today, the number of extinctions predicted to occur in the near future is unparralleled in Earth's history. Factors that contribute to this include

1. habitat loss
2. alien species
3. pollution- acid deposition, global warming, ozone depletion, synthetic organic chemicals
4. overexploitation
5. disease

Many individual species contribute beneficial services to human beings and the value that needs to be placed on biodiversity.

1. Medicinal value-many prescriptions originally derived from living organisms
2. Agricultural value- crops modified to be high producers originally from wild plants, flowering plants pollinated by wild animals
3. Consumptive use value

Indirect value

1. Waste disposal
2. Provision of Freshwater
3. Prevention of Soil Erosion
4. Biogeochemical cycles
5. Regulation of Climate
6. Ecotourism

Working Toward a Sustainable Society

A sustainable society would always be able to provide the same amount of goods and services for future generations the same as it does in the present. To achieve this resources must be preserved. A natural ecosystem makes use of only renewable solar energy, and materials cycle through back to producer (coral reefs).

Works Cited

Mader, Sylvia. Human Biology 10th ed

Frolich Powerpoint

Links to Pictures

Fetal Development Online Lab Unit 4

Fetal Development

There are many important developments from the time fertilization occurs to the time a baby is born. I am going to pick 10 events that I think are significant in this process.

1. Fertilization- This is when the sperm penetrates the egg and is the creation of a zygote. The whole process takes around 24 hours and occurs 1 day post ovulation.
2. Implantation-Trophoblast cells continue to engulf and destroy cells of the uterine lining stimulating new capillaries to grow and beginning the growth of the placenta. This is very important because this is where the fetus will live for the rest of the pregnancy. Implantation starts around day 5 and continues up to day 12
3. Embryonic period ends- By this time eyes, ears, and limbs are well formed. The embryo no longer has a tail, and intestines are starting to move into the body cavity. This event is important because now the first trimester is over. Major physiological changes have taken place and brain waves can be identified. This period ends at 56-60 days
4. Brain Structure in Place- Now things are really beginning to come together, vocal cords allow the fetus to make sounds, and sockets for teeth are forming along with hair follicles. Intestines have reached the abdominal cavity and start to practice contraction while the liver forms bile, and pancreas produces insulin. Genetalia are starting to form and the fetus is capable of reflexes. This is important because the different body systems are starting to function and practice for the real world. These events happen at 10 weeks after fertilization.
5. Baby Movement- The heartbeat can be heard clearly with external instruments. Sex organs are clearly distinguishable and the fetus is becoming more flexible with movements of head , mouth, lips, arms, wrist, hands, legs, and toes. This stage is important because it is becoming easier to monitor the progress of the baby and also all of the body systems are starting to work together. This happens at 12 weeks
6. Hearing Possible- bones of the ear harden and the fetus can hear sounds like mom breathing, heartbeat, and digestion. This is important because in this way the fetus is starting to interact with the outside. This happens at 22 weeks
7. Lungs Can Breathe Air- Lungs produce surfactant and are capable of breathing air. This is extremely important because it means the fetus is getting closer and closer to being able to survive on its own. This happens at 26 weeks
8. Brain Surface Convolutions Begin- Rythmic breathing and temperature is controlled entirly by the brain. Also red blood cell production has been taken over by red bone marrow. The baby is becoming more and more developed and its cellular functions are starting to work properly on their own. This happens at 28 weeks
9. Immune System develops- The fetus starts to develop its own immune system, and has sleeping cycles. Fetus can now scratch itself. This is important to have a functioning immune system for when the baby is born. This development starts at 32 weeks
10. Full term- All systems are complete and functioning. Baby now has 300 bones that will later fuse and turn into 206. There are 70 different reflex behaviors the nervous system can display that are unlearned and necessary for survival. The abdomin is plump with the liver producing red blood cells. The skull is composed of fontanels to ease with birth and the baby should have rotated with head down towards the cervix. The baby is ready to be born. 40 weeks

Works Cited

Visible Embryo Home Page www.visembryo.com/baby/index.html

Links for Pictures

1. http://health.state.ga.us/wrtk/images/n12weeks.jpg

2. http://www.baz.com/wendy/baby/mo1.jpg

3. http://www.dshs.state.tx.us/wrtk/graphics/22-weeks.jpg

4.http://health.state.ga.us/wrtk/images/p40weeks.jpg

5. http://www.pipetteco.com/Images/zygote.gif

Compendium Review Unit 4 Topic One

Table of Contents

Reproductive System

• Human Life Cycle
• Male Reproductive System
• Female Reproductive System
• Female Hormone Levels
• Control of Reproduction
• Sexually Transmitted Diseases

Development and Aging

• Fertilization
• Pre-Embryonic and Embryonic Development
• Fetal Development
• Pregnancy and Birth
• Development After Birth

Reproductive System

Human Life Cycle

The reproductive system is different between males and females. Puberty is when both males and females go from a child to a sexually competent young adult. The reproductive organs function to :

1. Produce sperm in the testes (male) and eggs in the ovaries (female)
2. Nurture and transport the sperm in ducts (male), transport eggs in uterine tubes to uterus (female)
3. Penis delivers sperm and vagina receives sperm and also transports menstrual fluid, and is the birth canal
4. The uterus is where a fertilized egg develops and the breast provide nourishment (milk) after birht
5. Testes and ovaries produce sex hormones that bring about masculinization and feminization and allow a pregnancy to continue

Mitosis is a duplication division while Meiosis is a reduction division. Meiosis takes place only in the testes in production of sperm and ovaries in the production of eggs. The chromosome number is reduced from 46 to 23 (haploid). Sperm carry only chromosomes while the egg provides the other half of chromosomes and cytoplasm for the new individual. The first cell of a new person is a zygote which has the total 46 chromosomes

Male Reproductive System

The primary sex organs of the male are paired testes suspended in the scrotum sacs. Sperm are produced in the testes and mature in the epididymis (tightly coiled duct outside of the testis). When the sperm leave the epididymis they enter the vas deferens. The vas deferens pass into the abdominal cavity, curving around the bladder and emptying into an ejaculatory duct which enters the utethra. When ejaculation occurs the sperm exit the penis in semen (made from secretions of the seminal vesicles, prostate gland, bulbourethral glands)

The male organ for sexual intercourse is the penis which is made of a long shaft and enlarged tip (glans penis). Circumcision is the surgical removal of the foreskin covering the glans penis. Spongy tissue that contains distensible blood spaces fills the shaft. In sexual arrousal, autonomic nerves release nitric oxide which leads to the production of cyclic guanosine monophosphate which causes the smooth muscle of incoming arterial walls to relax and allows the tissue to fill with blood. The veins taking blood away are compressed resulting in erection. Sperm enter the urethra and rythmic muscle contractions cause it to be expelled from the penis. There can be as many as 400 million sperm in 3.5 ml of semen expelled.

The testes start development in the abdominal cavity but descend into the scrotal sacs in the last two months of fetal development. The scrotum regulates the temperature of the testes by moving them closer or further away from the body. The testis is made up of compartments called lobules and each of these contain up to three coiled seminiferous tubules. These tubules are filled with cells undergoing spermatogenesis.

Spermatogonia divide into speratocytes that move away from the wall grow, and undergo meiosis 1 which results in spermatocytes with 23 chromosomes. These undergo meiosis 2 resulting in four spermatids which differentiate into sperm. Sertoli cells provide nourishment and support to this process which takes approximately 74 days. Mature sperm have a head, middle piece, and tail. The middle piece has mitochondria for energy to move the tail (flagellum). The head has the nucleus covered by an acrosome cap which has the enzymes needed to penetrate the egg. Sperm usually live no longer than 48 hours in the female genital tract.

Male sex hormones are androgens and are secreted by interstitial cells. The hypothalamus has ultimate control of the testes sexual function by secreting GnRH which stimulates the anterior pituitary to secrete the gonadotropic hormones (FSH and LH) Testosterone is essential for the normal developement and functioning in male sex organs. It brings about and maintains secondary sex characteristics.

Female Reproductive System

The female gonads are the ovaries, one on each side of the upper pelvic cavity. They produce eggs and estrogen and progesterone. Oviducts run from the uterus to the ovaries, but are not attatched to the ovaries. Fimbriae are projections that sweep over the ovaries. During ovulation, when an egg bursts from the ovary it is swept into the oviduct by the fimbriae and the cilia that line the oviducts. The egg then slowly moves towards the uterus where it can live for 6-24 hours without fertilization. Fertilization and the formation of a zygote usually happens in the oviducts and the embryo will arrive at the uterus several days later. Once in the uterus the embryo embeds into the uterine lining.

The uterus is a muscular organ that roughly resembles the size and shape of an inverted pear. The oviducts join the upper end , and at the lower end the cervix enters the vagina almost at a right angle. The uterus can stretch from 5cm wide to 30cm to accomadate a baby. Endometrium is the lining and helps in the formation of the placenta to supply nutrients for the embryonic and fetal development. There are two endometrial layers. The basal and inner functional layer. An opening in the cervix leads to the vaginal canal. The lining lies in folds and can extend which is important when it serves as the birth canal.

All of the external genital organs are known as the vulva (labia majora, labia minora, glans clitoris, urethra, vagina) The labia minora, vaginal wall, and clitoris become engorged with blood upon sexual stimulation. The labia majora enlarge and move away from the vaginal opening. Blood vessels in the vaginal wall release droplets of fluid that lubricate.

Female Hormone Levels

Hormone levels cycle on a monthly basis with the ovarian cycle driving the uterine cycle. An ovary has multiple follicles containing oocytes (immature eggs). As the follicle matures in the ovarian cycle it changes from a primary to a secondary to a vesicular follicle. A primary oocyte undergoes meiosis 1 resulting in haploid cells. One cell is a polar body that holds discarded chromosomes. The secondary oocyte undergoes meiosis 2 only if the egg gets fertilized. When its time the vesicular follicle bursts releasing the oocyte surrounded by a clear membrane (this is ovulation). The follicle then turns into a corpus luteum that disinigrates if fertilization does not occur. The corpus luteum is also responsible for producing progesterone.

The hypothalamus has ultimate control of the ovaries sexual function by secreting GnRH (stimulates production of FSH and LH). During the follicular phase, FSH promotes the development of follicles that secrete estrogen. Positive feedback leads to GnRH secretion, and ovulation around the 14th day of cycle. Next the luteal phase begins LH promotes corpus luteum development to secrete progesterone. If pregnancy doesn't happen, then menstration begins.

Estrogen promotes secondary sex characteristics, such as body hair, fat distribution, breast development. Menopause is when the ovarian cycle ceases. Estrogen and progesterone have many functions affecting the endometrium in the uterine cycle.

If the egg is fertilized, it becomes a zygote and develops as it travels down to the uterus. The placenta is made from maternal and fetal tissue and is where molecules exchange from maternal and fetal blood. Rising amounts of HCG maintain corpus luteum to produce progesterone and no new follicles begin in the ovary. At some point the placent begins to produce progesterone and some estrogen on its own.

Control of Reproduction

Birth control methods are used to regulate the number of children couples or an individual will have. Methods include:

1. Abstinence- not engaging in any sexual intercourse
2. Contraceptives
3. Intrauterine Device- inserted into the uterus preventing fertilization and implantation
4. Diaphragm-fits over the cervix
5. Condoms- cover the penis or female condoms fit on the cervix and cover external genitals
6. Contraceptive Implants- disrupt the ovarian cycle by releasing progesterone
7. Contraceptive Injections-progesterone only
8. Contraceptive Vaccines
9. Vasectomy- vas deferens are cut and tied off
10. Tubal ligation-cutting and sealing the oviducts

Infertilty is failure to achieve pregnancy after one year of regular, unprotected intercourse. Most causes are from low sperm count, or large amounts of abnormal sperm (from smoking, alcohol combined with a sedentary lifestyle). In females, body weight is the most significant factor. Assisted reproductive technologies include

1. Artificial insemination by a donor-
2. In Vitro Fertilization-
3. Gamete Intrafallopian Transfer
4. Surrogate Mothers
5. Intracytoplasmic Sperm Injection

Sexually Transmitted Diseases

These diseases are caused by viruses, bacteria, protists, fungi and animals

Virus caused STDs

1. HIV
2. AIDS
3. Genital Warts-caused by HPV. These lesions can be removed by surgery, freezing, burning, lasers, or acids
4. Genital Herpes- caused by herpes simplex virus. Causes cold sores and fever blisters
5. Hepatitis- Infects the liver, and can cause cancer that leads to death. Six viruses (A-G) cause hepatitis

Bacteria caused STDs-can be cured with antibiotics, although many strains are becoming resistant

1. Chlamydia- can result in PID in women if untreated
2. Conorrhea-thick green, yellow urethral discharge in males. Can also spread to internal body parts
3. Syphilis-can be treated by penicillin. Has three stages

Development and Aging

Fertilization

This is the union of a sperm and egg that forms a zygote. The flagellum of the sperm enables it to swim towards the egg. The mitochondria in the middle give it energy and the head which contains the nucleus enables to fuse with the egg. The plasma membrane of the egg is surrounded by zona pellucida which is surrounded by follicular cells(corona radiata). The acrosome allows the sperm to penetrate the zona pellucida

Pre-Embryonic and Embryonic Development

The processes of development are as follows

1. Cleavage-first after fertilization, zygote divides exponentially. This is mitotic division
2. Growth- daughter cells also increase size
3. Morphogenesis- embryo begins to assume various shapes
4. Differentiation- Cells take on specific structure and function (nervous system is first)

Extraembryonic membranes are outside the membrane

1. Chorion- develops into the fetal half of the placenta. Provides nourishment and oxygen and takes away waste
2. Allantois- extends away from the embryo. Later turns into urinary bladder. Takes blood to and from fetus
3. Yolk sac-First embryonic membrane that appears. First site for blood cell formation
4. Amnion-contains fluid that protects and cushions the embryo

Development is all the events from fertilization to birth. Due date is usually calculated by adding 280 days to the date of the last know menstration. Pre-embryonic development occurs in the first week. The zygote divides and becomes a morula and then a blastocyst. The cells of a blastocyst arrange to form and inner cell mass surrounded by an outer layer. Inner becomes the embryo and outer the chorion. Each cell in inner layer can become any type of tissue

Embryonic development starts with the second week all the way to the end of the second month. Implantation occurs and HCG is secreted by the chorion. Inner cell mass turns into the embryonic disk. Amniotic cavity surrounds the embryo. The nervous system and heart begin to appear during the third week. In the fourth and fifth week the umbilical cord is formed along with a head tail and limb buds. Sense organs become more prominant. In the sixth through eighth weeks the embryo is easily seen, and the nervous system can enables reflex reactions.

Fetal Development

The placenta produces progesterone and estrogen which function to prevent any new follicles from maturing and also to maintain the endometrium. The placenta has a fetal side contributed by the chorion and a maternal side of uterine tissues. Carbon dioxide and wastes move from the fetal side to maternal side and nutrients and oxygen move from the maternal side to fetal side.

The umbilical cord is the lifeline for the fetus. Umbilical arteries carry oxygen poor blood to the placenta and umbilical veins carry nutrients and oxygen from the placenta to the fetus. The circulatory changes that happen at birth are: the blood returns to the left side of the heart and a flap covers the oval opening, the arterial duct closes and the remains of this duct turn into conective tissue

Fetal development is from the third month to the ninth. The fetus is easily seen as human. In the third and fourth months fingernails, nipples, eyelashes, eyebrows and hair appear. Cartilage is turning to bone and the skull is formed of 6 fontanels. Around the third month sex can be distinguished, and in the fourth month the fetal heartbeat can be heard. In the fifth through seven months movement can be felt. Vernix caseosa coats the fetus and protects the skin from amniotic fluid. At the end of 9 months, the fetus rotates to point its head down toward the cervix and is ready to be born.

Sex is determined at the moment of fertilization, but the gonads do not develop until the seventh week. This is when the indifferent tissue becomes testes or ovaries depending on hormones. If the SRY gene is present testes will develop.

Pregnancy and Birth

Changes in the mother's body during pregnancy are due to placental hormones. At first the woman may feel nausea and fatigued, however these go away and many women have increased levels of energy and general sense of well being. Weight gain is due to breast and uterine enlargement, fetus weight, amniotic fluid, and the mother's own increase in body fluid. Progesterone relaxes smooth muscle including artery walls leading to lower blood pressure, and an increase in blood volume which also increases red blood cells. When the size of the uterus increases it pushes the intestines, liver, stomach and diaphragm down and widens the thoracic cavity. Blood carbon dioxide levels fall and this favors the flow from fetal blood to maternal blood. These effects are good, however the enlarged uterus can lead to stress incontinence, edema and varicose veins. The placenta also produces peptide hormones resulting in pregnancy induced diabetes.

The uterus has contractions throughout the pregnancy but as birth nears they become more noticible and closer together. Uterine contractions push the fetus down, stretching the cervix. The cervical canal disappears as the lower uterus is pulled towards the baby's head. The amniotic membrane ruptures. When the cervix is completely dialated, this is the end of stage one. In stage two the contractions are every 1-2 minutes and last for one minute, the baby's head comes down into the vagina and then the rest of the baby is delivered. When the umbilical cord is clamped and cut this ends stage two. Stage three is 15 minutes later with the delivery of the placenta.

Development After Birth

Development continues all through life. Gerontology is the study of aging and the goal is not to increase life span, but to increase the quality of this life span. Hypothesis about the cause of aging include:

1. Genetic in Origin
2. Whole-Body Process
3. Extrinsic Factors

As we age skin becomes thinner, less elastic and looses adipose. Cardiovascular disorders increase along with respiratory disorders. Blood flow to the liver decreases along with the kidneys. Response time can be slower and skelatal muscle mass can decrease. Along with the effects listed there are many other adverse effects to aging, but these are all not inevitable. Successful old age begins with good healthy habits that should be developed when we are younger.

Works Cited

Mader, Sylvia. Human Biology 10th ed

Frolich Power Point

Links for Pictures

1. http://www.ericolson.addr.com/assets/fertilization.jpg
2. http://www.choicetolivewith.com/FetalDevelopment/Week3/implantation2.jpg
3. http://cache.eb.com/eb/image?id=1078&rendTypeId=4
4. http://www.femcap.com/images/birth_control_methods.jpg
5. http://www.wales.nhs.uk/sites3/gallery/719/syphilisbacaterias.jpg
6. http://www.mhhe.com/biosci/esp/2002_general/Esp/folder_structure/re/m2/s2/assets/images/rem2s2_1.jpg
7. http://embryology.med.unsw.edu.au/Notes/images/placenta/plMembraneW450.jpg
8. http://embryology.med.unsw.edu.au/wwwhuman/Stages/Images/Cst800.jpg
9. http://www.sflifeandjustice.org/images/fetus1.jpg