Chapter 15 – Genetic Engineering

HOW AND WHY DO SCIENTISTS MANIPULATE DNA IN LIVING CELLS?

SOME REASONS WHY:

•Increase the yield from plants and animals (milk, beef, chicken, corn, soybeans, etc)

•Disease and pest prevention/resistance

•Cloning

•Medical Research

•Gene Therapy

•Genetic Testing

•Personal identification (DNA fingerprint)

15.1 Selective Breeding

Selective Breeding

-Taking advantage of naturally occurring genetic variations to pass wanted traits to the next generation.

Methods used to selectively breed:

  1. ______– crossing dissimilar individuals to bring together desirable characteristics from each

Ex. ______

2. ______– breeding individuals with similar characteristics to ensure unique traits are preserved (pure bred dogs)

15.2 Recombinant DNA Cont’d

Can we change the DNA of a living cell?

  1. Cut the DNA using ______
  2. ______with the gene or genes desired
  3. Enzymes like ______

______

Recombinant DNA – joining DNAfrom two or more different sources

Plasmids and Genetic Markers

Problem: DNA molecules insertedinto host cells were not replicated:

Solution:______

  1. Plasmid – ______
  2. Plasmids generally contain:

a. ______(ori),

b. ______start site (EcoR1)

  1. ______like antibiotic resistance genes (tetracycline and ampicillin)

Recombination Process using Plasmids

  1. ______is used to cut plasmid and DNA of interest
  2. The DNA of interest is joined to the plasmid using ligase
  3. Recombined DNA is ______
  4. The genetic marker (like antibiotic resistance) identifies the recombined DNA after bacterial growth

Use for recombined genes:

______, resistance of crops to pests and herbicides, pollution control, designer species

Transgenic Organisms

Transgenic –______, produced by insertion of recombinant DNA into the genome of a host organism

Used in plants, animals and microorganisms – ______

______

Transgenic Plants – transformed by using bacteria such as Agrobacterium, removing the cell wall or directly injected

Transgenic Animals – transformed by ______

______

In each case the goal is to have thehost cell combine the recombinant

DNA with its own chromosomes.

Cloning

Clone – ______

______

Steps in nuclear transplantation cloning:

•Nucleus of an unfertilized egg is removed

•Egg cell is fused with a donor cell that contains a nucleus

•The egg and donor cell are fused using an electric shock

•Diploid egg develops into an embryo

•Embryo is implanted in the uterine wall of a foster mother.

Animals cloned: ______

15.3 Applications of Genetic Engineering

Have you eaten genetically modified (GM) foods this week?

GM Crops –______

______.

-Use of these crops is on the rise

-Introduced in 1996 (soybean)

-As of 2007 GM crops made up 92% of soybeans, 86 % of cotton and 80% of corn

Examples: Roundup ready soybeans, Bt corn, tomatoes, rice, potatoes

GM Animals

GM animals – ______

______

______in US is coming fromcows injected with bovine growth

hormone (BGH)

In 2008, US approved the sale ofmeat and milk from cloned animals.

Examples of GM foods:

Cows – ______

Pigs – ______

Salmon – ______

Goats – ______

Gene Therapy

•Gene Therapy – ______

______

–The first attempted of a gene transfer to cure a disease occurred in 1990.

–Scientist ______to carry the new gene into the target cells

–Problem: ______and ensure DNA used does no harm.

DNA Fingerprinting

  1. Restriction enzymes are used to cut the DNA into fragments containing genes and repeats
  2. The restriction fragments are ______using gel electrophoresis
  3. The DNA fragments containing repeats are then labeled using radioactive probes. This labeling produces ______– the DNA fingerprint.