Life on Earth - Mutation and Alleles

Question 1

• What is a mutation?
• What is variation? What does it allow populations to do?

Answer 1

• a random change to genetic material.
• difference that exists between individuals
• allows a population to evolve in reponse to changes in environmental conditions

Question 2

What is an allele?

Answer 2

Different forms of a gene that produce different phenotypes

Question 3

What is mutagenic agent? Give examples.

Answer 3

• factors that can increase the rate of mutation
• Radiation (e.g. x-rays, UV light), some chemicals (mustard gas, bromine)

Question 4

• What is an adaptation?
• Name and describe the 2 types

Answer 4

An inherited characteristic that makes an organism suited to survival in its environment/niche.

structural - The physical features of an organism.
behavioural - The things organisms do to survive

Question 5

Define the following:
* selective advantage
* selective disadvantage

Answer 5

Selective advantage - a characteristic that gives an organism a better chance of survival and reproduction than other organisms.

a selective disadvantage does the opposite

Question 6

What is natural selection?

Answer 6

• The differential survival and reproduction of organisms due to differences in their phenotype
• Works by passing on beneficial genetic mutations through reproduction.