Modern Genetics

Genetic Engineering

Genetic Engineering The process of manipulating genes for practical purposes Today we can use genetic engineering to transfer genes from one organism into another. It also provides a way of producing large amounts of previously rare substances

Different enzymes can be used to cut, copy (clone), and move segments of DNA. An important category of enzyme used to cut a section of a gene and its DNA from an organism is known as a restriction enzyme. When this piece of DNA, which has been cut out of one organism, is placed in another organism, that section of gene will express the characteristics that were expressed by this gene in the organism it was taken from.

Ex: The human gene for insulin is inserted into bacteria Because the genetic code is universal, the human gene can be transcribed and translated by the bacteria, thereby creating large amounts of insulin

Regents Practice Question # 1 Which statement would most likely be used to describe the procedure represented in the diagram below? (1) Enzymes are used to assemble an insulin gene, which is then attached to bacterial DNA. (2) Bacterial DNA is cut from a human DNA strand and inserted into a human cell to form an insulin gene. (3) The insulin gene is cut out of a human DNA strand using an enzyme and inserted into bacterial DNA, resulting in a combination of different DNA segments. (4) A gene is deleted from bacterial DNA to produce an insulin gene, which is then inserted into human DNA.

Gel Electrophoresis

Gel electrophoresis is a group of techniques used to separate DNA based on size or shape http://learn.genetics.utah.edu/units/biotech/gel/

2.It can be used to: solve crimes determine paternity establish evolutionary relationships.

(1) X and Y, only (2) Y, only (3) Z, only (4) X, Y, and Z Regents Review Question DNA electrophoresis is used to study evolutionary relationships of species. The diagram below shows the results of DNA electrophoresis for four different Animal species. Which species has the most DNA in common with species A? (1) X and Y, only (2) Y, only (3) Z, only (4) X, Y, and Z

1: Who left the blood stExample ain? How do you know? http://www.biologycorner.com/resources/DNAfinger.gif

Example 2: Who are the children of these parents http://www.scq.ubc.ca/a-brief-tour-of-dna-fingerprinting/

Example 3: Who is the father? How do you know?

Selective Breeding

An Example of Selective Breeding Santa Gertrudis cattle: Formed by crossing Brahman and English shorthorns; has good heat resistance and beef. English shorthorn cattle: Good beef but poor heat resistance Brahman cattle: Good resistance to heat but poor beef.

Selective Breeding: Choosing the best traits for breeding. This involves crossing two individuals with different desirable traits to produce offspring with a combination of both desirable traits.

Examples of Desirable Traits Dogs that are good hunters. Cows that produce a lot of milk. Crops that are resistant to disease. Horses that can run fast.

Regents Practice Question #2 The pedigree of Seattle Slew, a racehorse considered by some to be one of the fastest horses that ever lived, includes very fast horses on both his mother’s side and his father’s side. Seattle Slew most likely was a result of (1) environmental selection (2) alteration of DNA molecules (3) selective breeding (4) a sudden mutation

Cloning

Cloning Cloning is the production of genetically identical cells from a single cell. It is easy to clone single cell organisms. Multicellular organisms more difficult to clone. A twin is a natural clone.

Cloning 1. A body cell is taken from a donor animal. 2. An egg cell is taken from a donor animal. 3. The nucleus is removed from the egg. 4.The body cell and egg are fused. 5. The fused cell begins dividing, becoming an embryo. 6. The embryo is implanted into the uterus of a foster mother. 7. The embryo develops into a cloned animal.

Regents Practice Question # 3 The diagram below represents the process used in 1996 to clone the first mammal, a sheep named Dolly. Which statement concerning Dolly is correct? Gametes from sheep A and sheep B were united to produce Dolly. (2) The chromosome makeup of Dolly is identical to that of sheep A. (3) Both Dolly and sheep C have identical DNA. (4) Dolly contains genes from sheep B and sheep C.

Cloning Humans?

Cloning… Ever since Dolly was successfully cloned the big question in genetics has been: "Is cloning moral, ethical? Is it right?" While this is in no way supposed to convert anyone to the "right" viewpoint, it is meant to educate and show that where there are pros to cloning, there are also cons. It is up to the individual to decide whether the pros outweigh the cons or vice versa. Also keep in mind that these are but a few of the issues brought up by cloning.

Cloning Pros: There is no better way to understand the human genome Ability to produce “superhumans” Will all but cease the production of lab animals Medicinal methods will be thrusted into a new era Further understanding of our past (evolution) Organ transplant waiting lists will be no more

Cloning Cons: Humans are sentient beings, they are not made to be specimens. They are of free will Ability to produce “Superhumans” Countries could clone armies If humans can be cloned, it makes them property, which can be sold. Inhumane If cloning is relied upon for reproduction and we lose the ability to clone, everyone will have the same genotype and to reproduce would be a sick twist of inbreeding. If everyone has the same genotype, a disease that is fatal for that genotype wipes out the human race

Environmental Issues… Notice how the classic issue of cloning Einstein to advance our science to an unthinkable level, or cloning Hitler to lead another holocaust isn't mentioned? That is because the whole idea is a farce. While the potential for those events to transpire still remains genetically there, they need to be environmentally influenced to happen. They need to have the same experiences. Remember that Einstein failed math as a child, but later was one of only 5 people who could mathematically understand his relativity proof? Or how Hitler was a humble, quiet person before "snapping"?

The End