Genetic Diversity

Question 1

Is there a lot of genetic diversity within a species?

Answer 1

No - they have same genes, variety of alleles within a species created by alleles

Question 2

Why is genetic diversity important?

Answer 2

Helps with survival, so that if the environment changes, there are likely to be some organisms with the alleles that enable them to survive new conditions

Question 3

Name & explain two factors that increase genetic diversity?

Answer 3

• gene flow: me members of a species migrating and reproducing with another gene pool
• mutation: forming new alleles

Question 4

Name 3 factors which decrease genetic diversity

Answer 4

• genetic bottleneck
• founder effect
• selective breeding

Question 5

Explain selective breeding and how it reduces genetic diversity

Answer 5

• artificial selection
• individuals with desired characteristics chosen to breed
• offspring without the characteristics eliminated
• unwanted characteristics bred out of population
• number of alleles reduced to only few desired ones

Question 6

Explain the founder effect & how it reduces genetic diversity

Answer 6

• a few individuals of a population migrate and colonize a new region
• they have small number of alleles
• this is not representative of alleles of whole population
• new population have less genetic diversity/ smaller gene pool
• new population in time will develop into new species, with small genetic diversity, meaning it is less likely to adapt to new environments

Question 7

Explain genetic bottlenecks and how they decrease genetic diversity

Answer 7

• after a catastrophic event population number is decreased
• small gene pool and few alleles in remaining survivors
• inter-breeding produces new population with small genetic diversity
• diversity is restricted as no new alleles are brought into gene pool by outside species/population
• genetic diversity of new population is lower than the original population

Question 8

Explain how a mutation in DNA increases genetic diversity

Answer 8

• mutation changes coding of amino acids and thus proteins produced
• with a wider range of alleles now in gene pool
• mutated genes passed down to next generation through reproduction

Question 9

Suggest how a mutation can lead to the production of a protein that has one amino acid missing

Answer 9

• DNA has a mutation that results in the loss of 3 bases (one triplet code)
• which would code for one amino acid (1 triplet code= 1 amino acid)

Question 10

What is genetic drift?

Answer 10

The changing of alleles in a population over time due to environmental changes or mutations

Question 11

Why is selective breeding done?

Answer 11

To produce livestock with greater yields

Question 12

Name two ethical issues with selective breeding

Answer 12

• by reducing allele variety we are forever losing alleles which might benefit mankind/ animals in future
• it’s interfering with nature

Question 13

What is genetic diversity?

Answer 13

The variety of DNA