7.1 - Biological Change over Time

Question 1

Neutral mutation

Answer 1

Mutation that does not result in any selective advantage or disadvantage; provides no benefit or harm to the individual

Question 2

Harmful mutation

Answer 2

Mutations that reduce the reproductive success of an individual and is therefore selected against. They do not accumulate over time.

Examples: Cystic fibrosis, Huntington’s disease

Question 3

Beneficial mutation

Answer 3

Mutations that increase the reproductive success of an organism and is therefore favoured. They accumulate over time.

Example: Sickle-cell allele gives carriers high resistance to malaria and increases their chances of survival

Question 4

Artificial selection

Answer 4

Directed breeding in which individuals with specific traits are chosen as parents of the next generation

Examples: Dog breeding from wolves & wild sea cabbage producing broccoli, cauliflower, cabbage, kale, etc.

Question 5

Advantages and disadvantages of artificial selection

Answer 5

Advantages: Can mass produce desired animal/plant species, beneficial mutations has positive consequences for species

Disadvantages: Reduces genetic diversity which contributes to the loss of biodiversity, cannot create traits that don’t already exist