Chapter 14

Question 1

What is genetic variation?

Answer 1

used to describe the variation in the DNA sequence in each of our genomes

Question 2

How can mutation cause a new species?

Answer 2

by a combined effort of mutations and natural selection and environmental changes can cause a change in organism that are so great a species is formed

Question 3

How does natural selection work?

Answer 3

• each species shows variation
• there is completion within each species for food, living space, water and mates (etc..)
• the ‘better adapted’ members of these species are more likely to survive
• these survivors will pass on their better genes to their offspring who will also show this beneficial variation

Question 4

What is selective breeding?

Answer 4

selecting animals or plants for breeding that have a required characteristic

Question 5

What are the 4 stages of selective breeding?

Answer 5

• decide which characteristics are important
• chose parents that show these characteristics
• select the best offspring from parents to breed next generation
• repeat the process continuously

Question 6

What is genetic engineering?

Answer 6

the deliberate modification of the characteristics of an organism by manipulating its genetic material

Question 7

What are the stages of genetic engineering?

Answer 7

• DNA containing the gene for making human protein insulin must be located
• specific enzyme is used to extract the required gene from the human chromosome
• plasmids removed from bacterial cell
• DNA of plasmids is cut open with a specific enzyme
• human insulin gene is inserted into each plasmid
• plasmid - vector, used to transfer DNA from one organism to another
• bacterial cells are designed to take up genetically modified plasmids
• if successful are described as being transformed., the bacteria are hosts for the plasmids
• each bacterial cell will produce a small mass of insulin
• culturing the genetically modified bacteria in large quantities of insulin protein can be produced and extracted