Variation And Evolution

Question 1

Variation

Answer 1

Variation is due to mutation with lots of different alleles, leading to a range of different phenotypes.

Question 2

Competition

Answer 2

Individuals within a population compete for water, food, mates, shelter and escape from predators.

Question 3

Survival of the fittest

Answer 3

Individuals where genes give them the ‘best’ characteristics are more likely to be the best competitors.

Question 4

Reproduction

Answer 4

Individuals are likely to pass on these specific beneficial genes.

Question 5

What is genetic engineering?

Answer 5

It involves modifying the genetic material of an organism, with the gene of a desirable characteristic cut out of an organism and transferred to the genetic material in the cells of another organism.

Question 6

What are the key steps in genetic engineering?

Answer 6

Enzymes are used to cut out the required gene from an organism.

The gene is then inserted into a vector using more enzymes.

The vector is then used to insert the gene into the required cells.

Question 7

Give 2 examples of how animals have been genetically engineered.

Answer 7

Animals are engineered to make complex human proteins in their milk.

Mice have been engineered to model human diseases including Alzheimer’s, cancer and diabetes.

Question 8

Give 3 examples of how plants have been genetically engineered.

Answer 8

Potatoes have been modified to make more starch and to be more resistant to several common pests.

Soybeans have been modified to produce a healthier balance of fatty acids.

Some GM grasses can absorb and break down explosive residues in the soil.