Warm-UP/ EOC Prep 1. The process by which homologous chromosomes exchange segments of DNA is • a. crossing over • b. independent assortment • c. segregation • d. fertilization 2. When a cell with 24 chromosomes divides by mitotic cell division, the resulting daughter cells will each have a maximum chromosome number of • a. 12 • b. 6 • c. 48 • d. 24
Agenda • Warm-up • Notes • Worksheet • Finish Projects • Cloning Webquest • Progress Reports will be issued tomorrow, as I need your projects in there to balance out the midterm grades. If you have missing work, turn it in TODAY!!!
The Human Genome Project is a research project in which teams of scientists joined together to identify all 3.2 million base pairs of the DNA that makes up the human genome. Over 20 scientific laboratories in six countries cooperated to figure out the human genome sequence and even they were surprised at some of the discoveries they made!
In February 2001, scientists working on the project published a draft of the genome sequence, but it is an ongoing process.
One of the things they found most surprising was the large amount of DNA that does not code for proteins. Each human cell contains about six feet of DNA, but less than 1 inch of that is devoted to coding for proteins.
Stretches of DNA that code for proteins are called exons, and stretches of DNA that do not code for proteins are called introns. About 1-1.5% of the human genome is DNA that codes for proteins.
If only a small amount of the human genome codes for proteins, how many genes are there? Before the project began, scientists predicted that human cells would contain about 120,000 genes. In reality, researchers found only 30-40,000 genes in each cell. This is only about double the number of genes in a fruit fly.
The purpose of the human genome project was not only to determine the DNA sequence, but also to identify and map every gene to its chromosome • The project was like putting a giant puzzle together. Since the sequence is so long, scientists cut up the genome into big pieces, sequenced the pieces, and then put them back together with the help of a computer.
The impact of the project on society comes in its ability to determine if individuals carry genes for genetic conditions and in developing gene therapy. • Gene therapy is when an absent or bad gene is replaced by a normal, working gene-however, gene therapy is still an unreliable and risky procedure and attempts have not always been successful.
Having a clear picture of our DNA may allow us to manipulate the sequence or alert us to any possible genetic disorders so that we can be as healthy as we can be!
Dolly—the first cloned sheep Ian Wilmut, the dude that did it
Wilmut first removed the nucleus from an egg cell and then took a mammary cell from an adult sheep and fused them together using electric shock. The egg was then placed into a surrogate mother or substitute mother so that the egg could develop.
Dolly’s Birth • Dolly was born July 5, 1996 and was genetically identical to the sheep that provided the mammary cell.
Dolly’s Death • On February 14, 2003, Dolly was euthanized because of a progressive lung disease.
Cloning is very difficult and attempts often fail. Even if a clone is produced, they may have health defects or fail to develop properly.
200 B.C. Humans “clone” trees by cuttings
1950 Humans clone frogs
1980’s Humans clone mice!
1996 HUMANS CLONE SHEEP!!!
1998 Humans clone 8 copies of a cow!!!
REVIEW Heterozygous or homozygous? BB Bb Dd dd
Ho He He Ho
What Blood type is it? AB AO BO OO
AB A B O
If a cell starting mitosis has 30 chromosomes, how many chromosomes will the daughter cells have?
If a cell starting meiosis has 20 chromosomes, how many chromosomes will the daughter cells have?
Clean up this room!! • That means… • No paper or trash on the floor • Chairs tucked under the desks • Desks straight • THANK YOU!!
Cool-Down 1- If you saw a baby with a webbed neck, what genetic disorder do they most likely have? 2- A karotype has 2 X and 1 Y chromosome. What genetic disorder? 3- Which disorder results from nondisjunction of chromosome 21?
Warm-Up / EOC Prep 1. If a child with the recessive trait of beautiful toes has a mother with heterozygous ugly toes and a father with ugly toes, what is the father’s genotype? A. uu B. Uu C. UU D. Uh 2. AJ has the dominant trait of being able to roll his tongue. His father cannot roll his tongue, and his mother’s mother cannot roll her tongue. What is AJ’s mother’s genotype? A. RR B. rr C. tongue roller D. Rr
Agenda • Warm-up • Notes • Vocab Game • Clean-up • Cool-down
Genetic Engineering Guided Notes
moving genes from one chromosome of one organism to the chromosome of another GENETIC ENGINEERING
DNA sequences can be changed in a number of ways. Short sequences can be put together or “spliced”. Genes from one organism can also be put into the DNA of another organism. The new DNA is called recombinant DNA because they are produced by combining DNA from different sources.
To study genes, biologists often need to make many copies of a particular gene. A technique called polymerase chain reaction (PCR), allows scientists to make many copies in a short amount of time.
Transformation is a procedure where a cell takes in DNA from outside the cell. This external DNA becomes part of the cell’s DNA. This is accomplished by using a plasmid. A plasmid is a small, circular piece of DNA. The foreign DNA is first joined to the plasmid, and then the plasmid is inserted into the cell’s DNA
If the transformation is successful, the recombinant DNA is integrated into one of the chromosomes of the cell where it will be replicated and used just like the cell’s original DNA.
Applications of genetic engineering include • 1. Transgenic organisms 2. Cloning
Transgenic organisms contain genes from other species (contain foreign DNA). There are three types of transgenic organisms: • 1. transgenic microorganisms • 2. transgenic animals • 3. transgenic plants.
Transgenic microorganisms are bacteria that are used to produce important substances useful for health and industry. The human forms of proteins such as insulin, growth hormone, and clotting factor, which are used to treat serious human diseases were once rare and expensive. Bacteria transformed with the genes for making human proteins now produce a lot of these important compounds cheaply.
Transgenic animals have been used to study genes and to improve the food supply. Mice have been produced with human genes that make their immune system act similarly to those of humans so we can study the effects of diseases on humans.