Grade 9 science: Reproduction Unit

Marge: Homey I brought some one here who thinks he can save you!

Homer: Batman?

Marge: No Homey, a scientist.

Homer: Batman's a scientist!!!!

Remember that not all science people are geeks, there are many cool jobs and people in the science field (especially Batman)

Cells: The Basic Unit of Life

- All plant and animal cells have common features to one and other, though there are differences.

- Both plant and animal cells contain the following parts:

- Cell membrane: controls the movement of materials into and out of the cell

- Nucleus: acts as the control centre directing all of the cells functions

- Nucleolus: involved in making of proteins (located inside of the nucleus)

- Chromosomes: contain hereditary genetic information which are organized into thread like structures

- Genes: (located in the chromosomes) these determine

characteristics of the organism

- Cytoplasm: absorbs, transports and processes nutrients

- Mitochondria: these tiny organelles provide the cell with energy

- Ribosome: organelles that build protein essential for cell growth and division

- Endoplasmic Reticulum: canal like structures that carry materials throughout the cell

Though there are many similarities, plant and animal cells differ greatly.

Structures found only in Animal Cells:

- Centriole: small protein structures critical for cell division

- Golgi Apparatus: structure which holds proteins until needed for use in or out of the cell

- Lysosome: formed by the Golgi apparatus, this contains protein capable of breaking down large molecules and other cell parts

Structures found only in Plant-Cells

- Cell wall: is a rigid structure containing cellulose, this rigid wall protects and supports plant cells

-Vacuole: fluid filled space containing water, sugar, minerals, and proteins

- Chloroplast: organelle containing chlorophyll used in photosynthesis

Mitosis and Cytokinesis

- During cell division the duplicated chromosomes move to the different poles of the cell, this process is called Mitosis

- Before Mitosis has completely taken place, the cytoplasm and its contents move into 2 equal parts and will eventually go to the daughter cells

- Cytokinesis differs b/w plant and animals cells

- Animal Cells: during mitosis the cell membrane pinches together creating two equal parts

- Plant Cells: due to the rigid cell walls the plant cell is unable to pinch together instead a new cell wall is created in the middle of the cell

- Through the act of Cytokinesis and Mitosis cell division takes place

- After division the daughter cells go through Interphase and will eventually divide

- It seems though that some cells have a limited number of divisions. Heart cells of chickens can only divide 50 times before they can no longer divide, other cells have other divisions maximums, but it seems that when this amount has been reached the cell can no longer and will no longer divide

Hmwrk: Draw out the Phases of Mitosis and label them. Also provide with those labels an idea of what is taking

Can human growth hormone slow aging?

Dear Cecil:

What is the story with human growth hormone (HGH)? I know that the actual hormone can be injected (at great expense), and some of the Hollywood crowd supposedly use this to stay young. However, a lot of companies are marketing "HGH enhancers," which are not HGH but supplements that are supposed to stimulate the body to produce HGH in greater quantities. The enhancers are much less expensive than actual HGH and supposedly almost as effective in raising your HGH level. So, does HGH really restore your youth? Do these HGH enhancers work? Or is it all placebo effect? —Richard Nash, via e-mail

Cecil replies:

Chances are you're going to be hearing a lot about HGH in the next few years. Consider the following facts: (1) The most promising test done on HGH so far involved men age 60 and up. (2) The leading edge of the baby-boom generation is now 58. If you're, say, Bill Clinton, born in 1946, you're looking in the mirror and thinking: You know, for an old fart, I don't look bad. How long can I hold off the inevitable? (3) Most of the crap you see touting HGH and so-called HGH enhancers is, in fact, crap. (4) However, some of it's not.

Here's the story so far. HGH is a chemical produced by the body that's essential to normal growth in children, and scientists have now come to realize it's important in adults, too. In many but not all elderly people, HGH levels drop well below those of adults in their prime, and some researchers think this leads to loss of lean body mass, increased body fat, and other hallmarks of aging. Before the mid-80s the sole source of HGH was the pituitary glands of cadavers, but gene-splicing technology has made it possible to produce synthetic HGH in quantity, though still at a stiff (sorry) price. To date the stuff has mostly been given to people with gland problems, e.g., kids who would otherwise be abnormally small. In 1990, however, the New England Journal of Medicine published a study by D. Rudman et al suggesting that giving synthetic HGH to healthy males over 60 with reduced levels of natural HGH significantly slowed aging. The Rudman group injected 12 men ages 61 to 81 with HGH three times a week. After six months they found that the men averaged 9 percent more lean body mass, 14 percent less body fat, 7 percent greater skin thickness, and a 2 percent increase in lumbar vertebra density. Meanwhile a control group showed no change.

But we don't know enough about possible long-term effects of supplemental HGH, and much of what we do know isn't good – serious drawbacks include increased risk of diabetes, arthritis, and congestive heart failure.

quick search of PubMed, an online medical journal index provided by the National Library of Medicine, shows roughly 150 reports on HGH and aging since the beginning of 2000. Data points pro and con:

* Multiple follow-up studies have confirmed the Rudman findings, although the ones I've seen were short-term and involved relatively few subjects. On the other hand, the impact of HGH on mental function – which many think is the key to long life – remains unclear.

* In one study, 18 men aged 65 to 82 underwent progressive strength training followed by more training plus HGH or placebo. The initial training significantly increased muscle strength, but HGH produced no additional benefit.

* Elevated levels of HGH derivative in the blood may increase the risk of cancer; reduced levels are associated with heart attack and atherosclerosis.

You're thinking: I'm getting mixed signals here. Exactly – we still don't know enough about HGH to proclaim it an elixir of youth. Luckily, other promising methods for cheating the reaper are available now and don't require expensive chemicals – exercise, for instance, or sharply reducing calorie intake. But the average American is likely to say, I think I'll wait for HGH.

The full story on aging is as yet incompletely known. Why do we age? What changes us, and what can we do about it to halt, reverse, or at least slow down this process? One factor which is important in the aging process, is the slowing down of the hormonal system, particularly the adrenal glands and the thyroid gland. A program to slow the aging process must take into consideration the function of these two glands or be woefully inadequate. Thyroid extract and DHEA have become mainstays in the treatment of premature aging. Human growth hormone (abbreviated HGH) is produced in the pituitary gland, a tiny gland at the base of the brain which regulates the endocrine glands. The pituitary is the master gland which regulates the entire hormone system. In fact, 40% of the anterior pituitary cells are "somatocytes," cells which make HGH. Based on the number of cells devoted to the job, nature seems to think the production of HGH is critically important.

HGH is in abundant supply in the normal young human being and is responsible for the final adult size of the body. It controls the size of muscles and internal organs and the length of bones. The bones of the legs and arms are lengthening in direct response to HGH until age eighteen. These bones fuse at age eighteen just at that place where lengthening is taking place. Final height and length of arms is determined by this event, since no further lengthening is possible after this fusion.

With aging, almost everything shrinks in size, and all the organs slow in metabolic rate: the heart, the kidneys, the liver, pancreas, digestive tract, etc. — all the organs, as well as muscle. The only thing which does not shrink in size is the percentage of body weight stored as fat. All other factors being equal the percent of body weight which is fat increases progressively.

In childhood, HGH causes the growth of long bones and this brings a person to his or her final height. Traditionally, this was all HGH was thought to do. New research shows that every cell in the body has HGH receptors and that HGH is doing a host of jobs in human metabolism in every organ in the body. There are even receptors in the brain the activation of which results in the production of endorphans, molecules which keep one's mood even and upbeat. Skin cells respond to HGH with even growth producing the smooth appearance of children's skin. Cells in the brain respond by literally coming back to life (about 10% of the brain cells become non-functional each decade of life). Thus, HGH is the latest and most effective treatment for Alzheimer's disease, although the large double-blind clinical trials have not yet been done.

One consistent effect of HGH deficiency is irritability and when a person receives replacement therapy this reverts to a profound sense of well-being. Bone cells respond by making new bone and osteoporosis reverses, although this effect requires two or more years for completion. Fat cells respond by giving up their little lives as they are burned for energy. The weight gain around the middle which is so characteristic of HGH deficiency, melts away in a few months. Muscle cells respond by becoming larger and stronger, especially in the upper body. The strength and endurance of youth reappears. Many people are able to read without reading glasses again as the ciliary muscle of the eye becomes stronger again.

The Biochemistry of HGH

The biochemistry of HGH is complex. It seems that we all have plenty of HGH, but as we age it is prevented from being released from the pituitary by deficiency of HGH releasing hormone (HGHRH) which is made in the hypothalamus of the brain and by a substance called HGHP, a peptide of seven small amino acids. One day it may be possible to supplement with one or both of these two substances and cause the release of your own HGH; however as yet these are not commercially available.

For people who want to get the full benefit of HGH, it is necessary to raise plasma levels to those enjoyed by the average person in his or her 20s. We need 30-50% of the amount children have and very few adults produce and release this much on his/her own.

Some of the effect of HGH are immediate: increased energy, ability to concentrate, interest and ability in sex; others take a few months to a year to show up: increased aerobic capacity and strength, thickening of hair, tightening of wrinkles and loose skin, decrease in visceral fat; and one takes two years: strengthening of osteoporotic bones.

HGH is a powerful rejuvenating agent. Unfortunately, it also is super-expensive. Many hormones are exactly the same in animals and humans, but human growth hormone is different from that produced in the pituitary gland of any other animal. Until recent years it had to be harvested in minute quantities from human pituitaries.

In the 1980s, it became possible to synthesize HGH using recombinant DNA techniques, coaxing bacteria to do the job by inserting the proper human gene into their genome. The average cost of one year of therapy is $10,000 which makes this a rich person's therapy. The price may come down in the future, but it will never be cheap.

In addition, HGH is stringently controlled. Because there is a potential for abuse, the legitimate need for HGH must be thoroughly documented. However, most people over age fifty, and many younger than that, can be shown to be in need of HGH for optimal health. In the ideal world, everyone in need of HGH would receive it. Because of economic and other considerations, only a fortunate few will receive it.

The Phases of Mitosis

- Mitosis is broken into 6 phases in which the cell goes through in the process of splitting.

1. Interphase: the cell grows then prepares for cell division bu duplicating its genetic material

2. Prophase: the individual chromosomes shorten and thicken, while the nuclear membrane dissolves

3. Metaphase: the double-stranded chromosomes line up in the middle of the cell

4. Anaphase: each chromosome splits. The two halves move to opposite poles of the cell

5. Telophase: the chromosomes reach the opposite poles of the cell and a nuclear membrane begins to form around each set. Cytokinesis begins and the cytoplasm and organelles separate into roughly equal parts, and the two daughter cells are formed

6. Interphase: the daughter cells begin growth and duplication of genetic material

Chapter 6 notes

DNA Mutations
If a computer programmer gets one little symbol wrong then the program will not work. The same with DNA if there is one little problem then a malfunction will occur.
- Changes to the DNA can be caused by many different factors, the altered DNA though is now referred to as Mutated
- Mutations can be beneficial to the DNA (X-men) but most are neutral (nothing happens) or damaging (can become cancer)
- Any substance or energy that causes mutations in cells are known as carcinogens
- All cancers are caused by mutations in the genes that regulate cell division
Cancer can be found in plants and animals not just humans. It has even been found in the linens of mummies
- Normal cells in a multicellular organism cannot divide when isolated from one another, cell - cell communication must take place
- Cancer cells on the contrary can divide in isolation as well they do not change shape and specialize like other cells (all cells have a specific shape for the task that they re required to do)
- So not only are cancer cells not able to carry out functions they are suppose to do but they are using up energy and resources of other cells of the body to reproduce

DNA: The Genetic Material
- All species have chromosomes humans have 46, a dog 70, etc.
- All chromosomes carry something in common, that being Deoxyribonucleic Acid (DNA)
- DNA provides the directions to guide the repair of worn cell parts and the construction of new ones, it also determines will respond to change in the environment and from messages from other cells
- DNA has an interesting structure in that it is made of a series chemicals called nitrogen bases
- DNA uses 4 character code made of the nitrogen bases:
A - Adenine T - Thymine
C - Cytosine G - Guanine
- This genetic code is arranged in a what can be described as “words”, three character sequences of nitrogen bases, these words combine together to form “stories”

- The DNA stories are genes
- Genes are what determines ones body shape, hair and eye colour, etc., genes are long strands of DNA
- This “language of life” is stored in 6 billion nitrogen bases of DNA, arranged in about 100 000 genes on the 46 human chromosomes
- DNA exist in the chromosomes, and during Mitosis the chromosomes make exact duplicates of themselves, this means that DNA has the ability to duplicate itself
- Mice and humans are different because the they have different genes from one and other, but humans differ from other humans because of small differences in the DNA coding
- Most people have 46 chromosomes, 23 from mother and 23 from father, these chromosomes carry the same genes, so you have two copies of every gene but there are small differences found within the code
Ex. If you receive coding from your father to have curly hair and coding from your mother to have straight hair then depending on their interaction you could have slightly curly hair, but if both parents send you curly hair genes then you will most likely have curly hair
- Everyone (except for identical twins) have different DNA, that is unique to yourself
- This allows people to identify you by using DNA, there is no known way to alter your DNA
Questions # 1-7 pg 178

BBC-Science and Nature-GM Monkey

If scientists discovered how to engineer your genes to guarantee a life free from cancer, or mental illness, would you want it done? How about athletic ability, or intelligence? It is possible that gene therapy could offer all these enhancements in the future.

Genetically modifying humans
In theory, modifying the DNA of humans could be done in two main ways:
1. The new genes could be put into a fully grown adult. One experimental treatment is aimed at people with cystic fibrosis. They have a faulty gene which results in the production of thick mucous in their lungs. It is not necessary to try to get the new DNA into every cell in their body because the faulty gene only causes damage in certain tissues, so the copies of the gene are sprayed into their lungs to be taken up by cells there.
In the future, however, it might be possible to make genetic changes to a stored supply of human cells outside the body and use these to replace damaged tissue.

2. Alternatively the new genes could be put into a sperm, an egg or an embryo. The embryo would then be transferred to a womb to develop. Making changes to a single cell means that when it divides, it will pass a copy to every new cell. In other words, the person will end up 100% genetically modified and will pass the changes onto their children in their own sperm or eggs. This is called germ line gene therapy and would make a permanent change which would be passed down the generations. For this reason, germ line gene therapy is highly controversial.
Genetically engineered babies might be possible - but experimenting would be too risky
Imagine allowing the first genetically-modified embryo to develop into a person. What would it be like? Would it suffer deformities or would other problems emerge in later life? Most people would find experimenting on babies unthinkable.

Andi the GM monkey
However, one of our closest relatives - the rhesus monkey - has already been engineered. Andi the GM monkey was given a jellyfish gene while still an unfertilised egg.
Does this mean humans could be engineered? Perhaps, in the future. At the moment the process is far too inefficient. When Andi was made, hundreds of eggs were wasted, and he was the only one of three monkeys born alive to carry any jellyfish genes. Such wastage could never be allowed to happen in humans.

# Why was Andi's birth so important?
The birth of a GM primate suggested GM babies would one day be feasible. However, it also proved how difficult it might be: from more than 40 embryos, Andi was the only GM primate to be born alive.

# Why didn't he glow?
Nobody knows. After Andi was born, analysis of his DNA showed he carried the gene.

# GM monkeys in medical research
Because they share so many of our genes, rhesus monkeys have been used in research for decades. They have even travelled into space. GM monkeys could now be engineered with genes for Alzheimer's and diabetes to test new treatments.

Many people are unhappy about using primates in laboratory research. Andi's birth sparked protest from various groups including the RSPCA.
http://www.betterhumans.com/News/news.aspx?articleID=2004-01-26-5

Sperm has been modified in a laboratory dish to produce genetically engineered animals, an achievement that researchers are calling a first and saying will have implications for modifying human genes to eliminate disease.
The researchers, from Fukui Prefectural University in Obama, Japan and the US National Human Genome Research Institute, have announced producing genetically modified zebrafish using sperm cells grown in laboratory dishes.

Although further testing is needed, the new technique could speed the production of genetically engineered animals used to study human development and disease.
It could also allow researchers to better study the biology of sperm production in vertebrates.
And perhaps most controversially, it could allow researchers to perform gene therapy to eliminate genetic diseases before babies are conceived, introducing genetic changes that would be passed to future generations.

Regeneration
If a person cuts off a finger there is a chance that it can be reattached and use regained. Some creatures have the ability to regrow new “fingers” or other body parts, this is called Regeneration.
- Regeneration is the ability to regrow tissue, organs, or part of the body
- Regeneration in humans is limited to skin, blood, and bone tissues, liver and kidneys also have minor regeneration abilities
- Through asexual reproduction certain organism (eg sponges) can multiply through fragmentation (basically regenerate a duplication of themselves)
- The more complex a species become the less regeneration abilities it contains, this is because more complex creatures have more specialized cells
- Non specialized cells are known as STEM CELLS
- Stem Cells are very important as they divide rapidly and then become specialized cells (bone, muscle, nerve, etc.)
- All the cells in ones body contains the same DNA but they read different parts of the DNA which gives them different instructions
- Specialized cells use only a very small part of the DNA coding, the genes on used are “turned off”
- Most specialized cells turn off the genes that would allow them to reproduce
- Humans contain stem cells in there skin, bone marrow, and some other tissues, this is why we can grow new skin so easily
- If specialized cells were able to “turn on” the reproduction switch they could start to divide, this would mean no longer would there be permanent spinal cord injuries nor would strokes have such an effect on our lives

http://www.usatoday.com/news/health/2004-08-26-stem-cell_x.htm

Gates, others lead California effort for stem cell research

SAN FRANCISCO (AP) — Silicon Valley tycoons, Nobel laureates and Hollywood celebrities are backing a measure on California's Nov. 2 ballot to devote $3 billion to human embryonic stem cell experiments in what would be the biggest-ever state-supported scientific research program in the country.

The measure — designed to get around the Bush administration's restrictions on the funding of such research — would put California at the very forefront of the field. It would dwarf all current stem cell projects in the United States, whether privately or publicly financed.

Proposition 71 promises to be one of the most contentious election issues in California, pitting scientists, sympathetic patients who could benefit from stem cells and biotechnology interests against the Roman Catholic Church and conservatives opposed to the research because it involves destroying days-old embryos and cloning.

What's more, cell research has emerged as a major campaign issue between President Bush and John Kerry, who promises if elected to reverse Bush's 2001 policy restricting federal funding of such experiments to only those cell lines already in existence.

The measure would authorize the state to sell $3 billion in bonds and then dispense nearly $300 million a year for 10 years to researchers for human embryonic stem cell experiments, including cloning projects intended solely for research purposes. It bans the funding of cloning to create babies.

The amount of money involved far exceeds the $25 million the federal government doled out last year for such research and surpassed even Kerry's promise to expand funding to $100 million annually.

Many scientists believe stem cells hold vast promise for treating an array of diseases from diabetes to Parkinson's. Stem cells can potentially grow into any type of human tissue and scientists hope to be able to direct the blank cells to grow into specific cell types needed for transplant.

Stem cells are harvested from embryos, which are destroyed in the process. They were first discovered in 1997 and even the research's most enthusiastic supporters acknowledge that medicines created with stem cells are still many years away.

Some 22 Nobel laureates and many other scientists support Proposition 71 as a way to get around the Bush administration restrictions. They complain that the political climate has brought the field to a virtual standstill in the United States.

Many expect Proposition 71 to instantly breathe new life into the field while also boosting California's biotechnology industry.

"Stem cell-based therapies have the potential to alleviate suffering for millions of Americans," said Leonard Zon, president of the International Society for Stem Cell Research. "If this proposition is accepted, it will place California at the forefront of stem cell research and therapies."

The vote could be close: An independent poll released Aug. 15 found that 45% of 534 likely voters questioned were in favor of the measure, 42% were opposed and 13% undecided.

The pro-Proposition 71 side has raised far more money than the anti camp: more than $12 million versus just $15,000, according to campaign finance records filed this week.

Among those bankrolling the measure is Bill Gates, who contributed $400,000 on Monday. Silicon Valley tycoons such as Google investor John Doerr and eBay founder Pierre Omidyar have donated millions.

Real estate developer Robert Klein II has donated $2 million. Klein's son suffers from juvenile diabetes.

Several prominent Republicans have also endorsed the research, most notably former first lady Nancy Reagan. Also, millionaire developer Thomas Coleman, a regular contributor to GOP candidates, has donated $378,000. Coleman's daughter has diabetes.

The measure has also been endorsed by actors Michael J. Fox, who has Parkinson's, and Christopher Reeve, who was paralyzed in a riding accident.

Opponents of Proposition 71 concede they will be fortunate if they raise $1 million by November. They said they will have to wage a small-scale campaign even as the pro-Proposition 71 side prepares to open a TV advertising blitz.

"This is something that was put on the ballot by venture capitalists and people who stand to benefit," said opposition campaign manager Wayne Johnson. "The more voters find out about this measure, the more they'll turn against it."

State budget hawks, including the California Republican Party, oppose the measure because it would sink the state deeper into debt.

Gov. Arnold Schwarzenegger has not taken a position on Proposition 71, and many predict he will not do so. Schwarzenegger has said he supports human embryonic stem cell research, but he has also vowed to stop California's slide into debt.

http://www.arkansasnews.com/archive/2004/08/26/News/279691.html

UAMS gets $18 million grant for adult stem cell research

Thursday, Aug 26, 2004

By Wesley Brown

Arkansas News Bureau

LITTLE ROCK - The University of Arkansas for Medical Sciences announced Wednesday that it had received a grant worth nearly $18 million from the National Cancer Institute, one of the largest awards ever given to the medical school.

The $17,954,098 grant was awarded to The Myeloma Institute for Research and Therapy, part of the Arkansas Cancer Research Center at UAMS.

The grant will fund an ongoing comprehensive stem-cell research program on multiple myeloma, a rare and incurable bone marrow cancer. It will be distributed over a five-year period, concluding in June 2009, hospital officials said.

The research does not involve the controversial harvesting of embryonic stem cells, which President Bush has limited funding toward.

Embryonic stem cells are taken from an embryo in the earliest stage, just after conception. Adult stem cells are found in organs, in bone marrow and in the umbilical cord blood of newborn babies.

UAMS spokesman Tim Taylor said the research at UAMS will center on the adult cancer patients, an ongoing program at the Myeloma Institute.

"They take them out of the patient, and put them back in," Taylor said of the stem cells that are given back to the patient to promote recovery from chemotherapy.

Hospital officials said the new funds are earmarked for four research projects as well as four supportive areas at the institute, the first facility in the world created specifically to study and treat this rare form of cancer.

The average survival rate of a myeloma patient used to be two to three years upon diagnosis. Thanks to research funded in part by the NCI, the average survival rate has extended to seven years and beyond, hospital official said.

In June, the institute marked a milestone by performing its 5,000th stem-cell transplant, more than any other facility in the world. Additionally, an endowed chair for myeloma research has been named in honor of the institute's director, Dr. Bart Barlogie.

The research center will be moving into new facilities to allow the institute to expand both its clinical and research capabilities.

"This grant is a testament to the work of Dr. Barlogie and his group in the myeloma program," Dr. James Y. Suen, UAMS' Cancer Research Center director, said in a news release.

"After 5,000 transplants, we know more about myeloma and how to treat it than anybody else in the world," said Barlogie, who received the Robert A. Kyle Lifetime Achievement Award from the International Myeloma Foundation in May for his years of dedication to finding a cure for myeloma. "We've learned so much from our patients, about their needs and what works best for them."

Three years ago, the Bush administration limited funding of embryonic stem cell research after expressing concerns that harvesting the cells required the destruction of human embryos.

Embryonic stem cells are widely assumed to be most promising because they are entirely undifferentiated. Unlike adult stem cells, they have not already been given a job to do.

Scientists believe both types of stem cells eventually can be used to replace dead or damaged cells as treatments for Parkinson's disease, spinal cord injury, heart disease and other ills.

Today only 21 of the initial 78 stem cell lines are available to researchers. Scientists say more than 100 new lines have been developed since Bush's cutoff date, some of which are much better suited for research.

Transplanting Organs

Every year thousands of people require organ transplants. The problem with this is there are not nearly enough healthy organs to donate to meet the needs of all of the expecting donors. Scientist originally thought of using animal organs to meet the needs of organs but, these organs were rejected by the human body which would kill these “alien” organs. To try and solve this issue, scientist transferred human genes into the nuclei of the pig embryo cells, as the cells develop they would copy the human DNA as it own. The animal organs (typically pigs) then would have human DNA and have a greater chance of being accepted by the human host.

Key Points

- Transferring human genes into pig embryo

- Pigs developing with human and pig genes

- The human genes cause the cells to create human proteins within the pig’s cells

- Pig organs used in transplants and not being rejected by the host

- The thought is that one could provide the doctors with DNA and then they could use this DNA to grow a pig with the same DNA so as to have a very high chance of acceptance by the host

Pros

Human organ black market is not joke but a thriving reality. Organs taken from executed prisoners (in China) too poor people selling a kidney

Cons

Pigs with human genes

Possibility of new diseases that grow from these cells

The Myth of Cloning

Cloning is not just some crazy scientist kind of adventure, instead cloning is something that has been taking place since the beginning of time.

- Cloning is the process of forming identical offsprings from a

single cell organism or tissue

- Clones are always identical to parent as it only come from one

- B/c clones only have one parent this is called Asexual reproduction

The first plant cloning occurred in 1958. Dr. Frederick Stewart cloned a carrot from the cell of the mother carrot. This provided an exact duplicate of the mother carrot. What are the benefits to cloning plants?

Cloning Plants

- When cloning animals the nucleus from an unfertilized egg cell needs to be extracted, the cell without the nucleus is called an “enucleated” cell

- a nucleus from an embryo (in early developmental stage) is extracted and then inserted into the enucleated cell

- The egg cell with the transplanted nucleus begins to divide much like a normal fertilized egg cell

- The adult frog had characteristics to the frog that donated the transplanted nucleus

The Dolly Revolution

Before Dolly it was believed that only non specialized cells could be used for cloning the creation of Dolly proved this all wrong.

- Cells from the udder of a Finn Dorset sheep were removed and starved

- A nucleus was then removed and placed into an enucleated egg cell from a Poll Dorset sheep

- The dividing embryo was then put into the womb of a Scottish Blackface sheep

- The result was an exact copy of the Finn Dorset, DNA and all

Sexual Reproduction and the Diversity of Life
Reproduction:
- Reproduction is the creating of new life and happens in many different ways

Asexual Reproduction:
- One parent and its offspring are genetically identical

Sexual Reproduction:
- Sexual reproduction is common for multicellular organisms
- 2 parents for offspring
- Offspring are not genetically identical to either parent, instead they are a combination of the two
- In complex animals, specialized sex cells are usually the means by which genetic information is passed along
- Specialized sex cells in males are typically sperm and females are eggs, these combine to form a zygote (Zygote is a fertilized egg cell)
- Sexual reproduction produces new combinations of genes ensuring that no two sexual offspring are identical
- This form of reproduction also allows for environmental changes making offspring more suited to the environment

Conjugation
- bacteria typically reproduce asexually but they due also reproduce sexually, this is Conjugation
- two cells come in contact with each other and exchange small pieces, rarely all, of their genetic information
- conjugation increases the diversity of bacteria and helps to create super bacteria

Hermaphrodites:
- Sexual reproduction is difficult for organism that have restricted movement as they are unable to reach a partner (eg sponges and tomatoes)
- Solution to this is hermaphroditic reproduction, or a species that creates both male and female sex cells
- These creatures create both sperm of the male and eggs of the female
- In some cases hermaphrodites can join together and deposit sperm into the other animal (worms)
- Animal hermaphrodites release sperm into the water at a certain time every year
- Plants release pollen or have it carried by bees or other insects

Separate Sexes:
- Most animals and some plants have separate sexes (males and females)
- Males produce sperm and females produce eggs
- The determination of male and female in humans is found in the chromosomes, called the X and Y
- Females (humans) have a pair of X chromosomes in each cell (one from each parent)
- Males have a single X chromosome (from mother) and a much smaller Y chromosome (from father) in each cell
- Fertilization takes place in 2 different methods: Internal and External fertilization
* Internal: male deposits sperm inside the body of the female, eg dogs
* External: male releases sperm after female has released eggs. The sex cells unite out of the female body, eg fish

Chromosome Number and the Formation of Sex Cells
- Human cells contain 46 chromosomes. If these 46 chromosomes paired with another 46 chromosomes you would have 92, and then 184, etc.
- The process that forms sex cells is meiosis. During Meiosis the chromosome number is cut in half to23 chromosomes
- The 46-chromosome number is referred to as the diploid chromosome #, and is written as 2n
- The 23-chromosome # is referred to as the haploid chromosome # and is given the symbol n
- A haploid sperm cell and a haploid egg cell will create a diploid zygote

Aphids: Both Sexual and Asexual
- Aphids are the tiny little insects you may see underneath a leaf in the spring time
- Female aphids during the summer months will give birth asexually to female aphids
- The newborn aphids have unfertilized eggs that will start to develop into other female aphids (almost like summer aphids are born pregnant)
- In the fall when temperatures start to get cooler, some of the female aphids turn into males (scientist unsure how this process takes place)
- The “new” males fertilize female eggs that can survive over the winter
- These offspring carrier genetic information from both parents

Reproduction in Flowering Plants

- A plants flowers contain its reproductive cells, many plants have both male and female sex organs and therefore are hermaphrodites
- Some plants have different flowers with different sex organisms (eg one flower is female, and the other plant is a male) while other plants have both sex organisms in one flower
- Some trees (eg poplars) can be male or female, so there are male and female poplar trees
- Pollen (the male sex cells) is pollen and produced in the anthers which are the tips of the stamens
- Female sex cells (called eggs) are located in a structure called ovary which is at the base of the pistil

Pollination
- Pollination is the process by which the pollen is moved from the anther to the female eggs cell and fertilize those cells
- In some plants the pollen can fertilize the eggs in the same flower
- In many plants the pollen has to travel to another flower before it can fertilize an egg cell

Seed and Fruit Formation
- The fertilized eggs (zygote) of the flower become the seed
- The petals slowly shrivel and fall from the plant
- In some species the ovary surrounding the zygotes develops into fruit
- Fruits hlp protect and disperse the seeds
- There are many different types of fruits, these are often eaten by animals and the seeds scattered in the droppings of animals

Pg 209 #1-6 also draw the life cycle of a flowering tomato plant

Reproduction of Plants for Food
Strategies for Increasing Food Production:
Selective Breeding:
- Most plants have historically had one or two characteristics that make them desirable (eg drought resistant, bug resistant, etc.)
- Cross breeding of plants is taking the pollen from one plant and fertilizing the eggs of another plant to give you a new plant that has the desired characteristics of both parent plants
- This pattern may produce the plants with the worst characteristics as well, these plants are removed and only the desired plants are kept and bred again
- After several generations of selective breeding all the offspring have the desired characteristics

Cloning:
- In cloning plants for food, a cutting from a plant with the desired characteristics is taken, and since cloning is asexual all it offspring will have identical characteristics

Grafting:
*This is common with fruit trees
- Some tree produce great fruit but poor roots and therefore die over the winter
- Other trees produce little fruit but have great root systems allowing them to survive the winter
- Branches from trees with excellent fruit are taken and grafted on to trees with poor fruit but excellent root systems

Sex Cell Development in Males

Structure of Sperm:
- The sperm cell is designed for the purpose of motion

- Reduced cytoplasm surrounds the nucleus, this is beneficial for a cell that must move but presents a problem as it has a limited energy reserve

Sperm Production and Development:

- Testis is primary reproductive organ of the male mammal

- Testis produce and nourish the sperm as they mature

- The insides of the testis are filled with tiny, twisting tubes; these seminiferous tubules are lined with reproductive cells that produce sex cells through meiosis
- Human reproductive cells are diploid while the mature human sperm are haploid
- Sperm are not built to last, those that are not used die after several days and are replaced by newer cells from the testes

Fertilization:
- In mammals fertilization is internal, each egg is fertilized by one sperm
- The sperms uses its stored energy to enter the egg, though only the head of the sperm is permitted to enter, the body remains out side
- As soon as one sperm enters, the egg puts up a barrier so that other sperm cannot enter
- Once inside the egg, the sperm’s nucleus merges with the nucleus of the egg

Hormones and Female Sex cell Production:

- Not until week 7 of fertilization is there any differences b/w male and female embryos
- Week 7 a chemical messenger ( a hormone) is sent from the brain to stimulate the development of sexual structures
- After birth both male and female sex organs produce very low levels of sex hormones
- These sex hormones continue to play a role in development of characteristics but reproductive organs are not capable of producing mature sex cells until puberty
- Puberty is a stage of rapid growth and sexual maturity that typically takes place b/w the ages of 9 -15
- During this time, the amount of testosterone produced increases which stimulates sperm development
- Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) are both hormones released by the brain and are important in the development of testosterone and sperm
Questions # 1-6, pg. 215

Sex Cell Development in Females
In humans the female reproduction organs are far more complex then those of males because is has the responsibility of nurturing the embryo.

Structure of the Egg:
- The egg is much larger then sperm and is packed with nutrients so when it is fertilized it can divide rapidly
- After fertilized it has the ability to build a barrier from other sperm
- Millions of sperm are produced daily by males, females usually develop one egg at a time

Production and Development of the Egg:
- Primary reproductive organ of the female is the ovary, it is responsible for producing and developing egg cells
- The ovary contains the follicles
- Follicles are composed of 2 types of cells: reproductive cells and nutrient producing cells (creates energy rich chemicals)
- Human ovary contains about 400,000 immature follicles at puberty, this # continually decreases
- Hundreds of follicles develop every cycle but normally only a single follicle is allowed to reach maturity in each cycle
- As follicles develop, they go through meiosis, which forms one large egg with 23 chromosomes and three smaller eggs that disintegrate
- When the nutrient eggs are ready the ovary will; burst and the egg cell is released into the oviduct, the release process is called ovulation
- Nutrient cells that remain in the ovary are transformed into a tissue called corpus luteum which secretes hormones that are essential for pregnancy
- If fertilization does not occur then after 10 days the cycle that leads to ovulation begins again

Pregnancy:
- If an egg is fertilized by a sperm cell while moving through the oviduct, the zygote divides by mitosis becoming an embryo
- If the egg is not fertilized then it is shed in a process called menstruation

The Role of Hormones:
- Females in puberty, the pituitary gland in the brain secretes two hormones, FSH & LH, which stimulate the changes that take place in the female body
- Hormones are also responsible for the development of internal and external sexual organs

Estrogen:
- FSH triggers the development of follicle cells in the ovary
- As ovaries develop they secrete estrogen
- Estrogen encourages the endometrium to thicken in preparation for the zygote

Atypical Meiosis

- If an error occurs during division of a somatic cell (ex. skin or liver) it may not hurt the organism.
- If something goes wrong with during Meiosis in a reproductive cell the resulting embryo is in serious trouble
- Nondisjunction (failure to separate) is an error that occurs when 2 homologous chromosomes move to the same pole during meiosis
- The result is that one of the daughter cells is missing a chromosome while the other has an extra chromosome
- Cells that lack or have to much genetic information will not function properly
- In humans, nondisjunction can produce sex cells with 22 or 24 chromosomes
- The sex cell with 24 chromosomes has both chromosomes from one of the homologous pairs. If this sex cell joins with a normal sex cell, the zygote will have 47 chromosomes, if the sex cell only has 22 then the zygote will have 45
- When the fertilized egg with an abnormal # of chromosomes begins to divide each cell in the body will have this abnormal # of chromosomes
- In most cases the zygote will die if there is too many abnormalities, in a few cases a person with a nondisjunction is born

Nondisjunction Disorders
- Down syndrome is a genetic disorder produced by nondisjunction
- Most people with down syndrome have an extra chromosome on the 21 pair, an ex of too much information
- The multi capabilities of a person with Down syndrome varies greatly form individual to individual, with severities differing
- It is estimated that 1/600 children are born with Down Syndrome

Turner Syndrome:
-Turner syndrome occurs when either sex chromosomes undergo nondisjunction in either the male or female parent
- This produces a female with a single x chromosome instead of 2
- Females with turners will never reach maturity and are shorter in height then the average women
- Turner syndrome effects 1/10 000 females

Klinefelter syndrome
- Is a nondisjunction caused by either the male or female sex cell
- The child receives two X chromosomes and one Y chromosome
- The child is a male, but with the onset of puberty they start producing high levels of female sex hormones, making it impossible for them to father children
- Klinefelter effects 1/1000 males

Questions pg. 223 #1 - 7

Survival and Development of Organisms

- There are 4 main means by which living organisms develop and nurture their offspring: Spores, Seeds, Eggs and development in the womb.

Spores:
- A spore is a reproductive body encased within a protective shell
- If bad environmental conditions these spores will exist in suspended animation until the environment becomes suitable for their development
- Spores contain genetic information which are surrounded by a tough cell wall (ex. bacteria)

Seeds:
- A seed contains the plant embryo wrapped in a protective package that contains food
- Seeds bring with them nutrients so as to get a head start on life
- Oranges would be and ex. of a protected seed, while pine cones are examples of a “naked” (not protected) seed
- Seeds are formed by the ovary of the flower

Eggs:
- An egg is a zygote and some food with some sort of mechanism for protection (ex. a hard shell)
- Some animals fertilize the eggs internally (ex. birds) and others externally (ex. fish)
- Species like the tape worm will lay thousands of eggs at once so as to ensure that some of the eggs will hatch

Marsupial Mammals:
- The offspring are born tiny and immature (ex. kangaroos)
- After emerging from the uterus they crawl into a pouch and attach themselves to a nipple
- When large enough these creatures will leave the pouch and return for milk as long as the mother allows

Placental Mammals:
- Young develop in the uterus or womb (this is most mammals)
- Nutrients from the mother pass along into the embryo, waste from the embryo is also diffused into the mothers blood and passed along to be excreted
- Placental mammals develop less quickly then other types of mammals and require greater long term care
- The mother is required to provide her young with milk and protection as well as teach them about survival
Questions: 1 - 4 pg. 235

Human Conception and Pregnancy

- During intercourse about 150 - 300 million sperm are released, however only a couple of hundred reach the oviducts and egg
- The sperm can exist in the oviduct for up to 5 days, while the egg is capable of surviving for only 48hrs if it is not fertilized
- Within hours of fertilization, tiny hairlike cilia line the oviduct moving the zygote into the uterus
- Around the 4 day, a 16-cell mass enters the uterus where it floats freely for two days, while the cells continue to divide to about100 cells, at this point it implants itself onto the wall of the endometrium and is know called an embryo
- The placenta is created through the joining of embryonic and maternal blood vessels
- Through the placenta nutrients and oxygen diffuse from the mothers blood vessels to the child and waste moves from the child to the mother through the same method
- The placenta after 3 months of pregnancy produces large amounts of estrogen and progesterone so as to ensure that she cannot conceive again until after birth

Human Reproductive Technology

No other technology in terms of medicine has had such mixed views as that of reproductive technology. People normally due not argue against advancements in heart or brain surgery, but they due argue against the development of reproductive technology. Reproductive technology is not only changing the way babies are born but also the very laws that determine parenthood and responsibility. Most people who use reproductive technology due so because for some reason they are not able to conceive a child whether it be the male or female whose sex organs are faulted in some manner.

Using Reproductive Technology (copy from here on)

Fertility Drugs (Fd):
- Fd stimulate the action of hormones from the pituitary
- Fd stimulate follicle development in the ovary making it possible that one or more egg cells may be released
- Fd actually increases the chances of having multiple births (octuplets, poor Apu)

Cytoplasmic Transfer (CT):
- CT the cytoplasm from an egg from a younger women is transferred into the egg cell of an older women
- It is believed that this transfer reduces genetic defects following fertilization

Intrauterine Insemination (Ii):
- Ii is the transferring of sperm directly to the oviducts directly after ovulation
- This ensures that more sperm make it to the egg, increasing the chances of fertilization

Gamete Intrafallopian Transfer (GIT):
- GIT involves the sperm and egg being inserted in the oviduct
- This technique is believed to increase the chances of successful fertilization by bringing the 2 sex cells togther

In Vitro Fertilization (IVF):
- The first step of IVF is the use of hormones to prepare the ovaries for ovulation
- During ovulation a physician locates the ovary and a mature egg is removed via suction
- This egg is then fertilized with a partners sperm
- One or more of these embryos are then transferred back into the uterus
- If one or more of these embryos implants, a baby will be born

Egg Freezing and Egg Donations:
- Fertility drugs are used to initiate multiple ovulations
- A single egg maybe fertilized, the excess eggs are frozen after fertilization
- These zygotes can be implanted into the mother at a later time or donated to another women or to science

Embryo Transfer:
- A women with a defective cervix or uterus can ask another women to carry her child
- the egg from the first women is combined with the sperm of the male partner and then placed in the “surrogate” mother who carries the child to term and then gives it back to the biological parents

The Human Embryo

- You begin your life as a single cell about the size of the dot on an “i”
- In a mere 280 days (nine months) you grew into a baby composed of trillions of cells
- Never again the does the human body grow that fast or that diversely again
- By the fourth week of pregnancy the yolk sac which has no nutrient value in humans develops beside the embryo
- A membrane called the amnion develops into a fluid filled sac that insulates the embryo
- Blood vessels from the embryo and the mother’s endometrium form the placenta

First Trimester
- This stage lasts from fertilization to the end of the third month
- By the end of the first month the embryo is 7mm long, 500 times larger than the fertilized egg
- By the end of the first month the 4 chamber heart has formed, a large interior brain is visible, and limb buds with tiny fingers and toes have developed
- At the end of the second month the cartilage of the embryo’s skeleton begins to be replaced by bone and the embryo is now called a fetus
- Most body parts have formed and a sucking reflex can be seen

Second Trimester
- The 57mm fetus moves enough for the mother to feel it
- All the organs have formed and like other mammals soft hair covers the entire body
- Early in the fourth month the fetus begins to swallow amniotic fluid and hiccups
- In the fifth month they are sucking there thumbs
- Sixth month eyelids and eyelashes have formed
- Most of the cartilage in the skeleton has been replaced by bone
- If the mother goes into labor at the end of the second trimester there is a chance that the 350mm, 680g fetus will survive

Third Trimester
- During the third trimester from the 7th month until birth the fetus grow rapidly
- The organ systems established during the first two trimesters begin to function properly
- The babies mass and size continue to increase during this time
Questions 1-5 pg 251

Fetal Alcohol Syndrome (FAS)

- The placenta acts as a barrier against large molecules but does allow smaller molecules, like oxygen, through
- Other molecules though are also able to slip through such as alcohol, drugs, tobacco, etc.
- When a mother consumes things like alcohol it crosses the placenta and enters the blood of the embryo
- (The effects on an adult (over 19) when drinking the alcohol depresses the functioning of the nervous system, it is also a poison which is broken down in the liver)
- The effects on the embryo are the same on the child as they are on the mother, the child’s nervous system is depressed and the “poison” remains in the liver
- Unfortunately the liver is not developed until the last few months of pregnancy, therefore the alcohol exist in the baby for much longer then the mother
- Alcohol has the potential to kill many different embryonic cells it also can change the genetic information in some cells producing a mutation
- There are many different defects associated with FAS:
- mental disabilities - abnormal facial features
- central nervous system damage
- behaviourial difficulties - growth deficiencies

- The severity of FAS depends on the amount of alcohol consumed by the mother and at what stage the alcohol was consumed
- It is estimated that 60% - 70% of women who are alcoholics give birth to FAS babies
- A women does not need to be an alcoholic to have a child with FAS, women who have admitted to having a glass a day or less on average have born babies with FAS
- Alcohol is the leading cause of fetal damage in the country and the leading cause of preventable mental disabilities

Birth

- Approximately 9 months after conception the contractions of the muscles of the uterus signal the beginning of parturition (the beginning of the birth process)
- The process is as follows: the cervix begins to dilate, or open. The membrane surround the baby is forced into the vagina, the amniotic membrane breaks (also known as water breaks) lubricating the canal
- Once the cervix has dilated enough the uterine contractions push the head into the birth canal and the baby slips out
- Post birth the baby is still attached to the mother via the umbilical cord
- One the flow of blood is severed from the cord to the child the child must start breathing on its own
- The umbilical cord is then cut and tied to stop bleeding. The dead tissue will fall off after several weeks
- Hormones are a major part of the birthing process, prior to labor the hormone relaxin is produced by the placenta this causes ligaments in the pelvis to loosen which provides a more flexible passageway for the baby
- Oxytocin is also produced, this causes strong uterine contractions which pushes the baby into the birth canal

Hormones and Lactation
- Breast are produced at birth due to estrogen, during puberty estrogen and progesterone prepare the breasts for milk production
- At birth the mother’s pituitary gland in the brain secretes prolactin, this stimulates the glands in the breast to begin producing fluids
- Milk production is stimulated by the baby’s sucking action and the removal of milk

Milk and the Mother
- Milk takes a lot of energy and nutrients from the mother to produce
- Human milk contains 50% more lactose then does cows milk
- At the peak of lactation the mother can produce up to 1.5L of milk a day
- A mother producing that much milk would need to consume 50g of fat, 100g of lactose, and 3g of calcium phosphate each day to replace her losses
- A mothers body will actually take nutrients from her own bones if she is not getting enough of them in her diet to supplement these losses