variation in population

Question 1

What can variation be due to?

Answer 1

Genetic and environmental factors

Question 2

What is the main source of genetic variation?

Answer 2

Mutation

Question 3

What are the other sources of genetic variation?

Answer 3

Meiosis and random fertilisation

Question 4

What are gene mutations?

Answer 4

Changes in the base sequence of DNA resulting in a production of different peptides

Question 5

What is crossing over?

Answer 5

During meiosis, the exchange of alleles of the same genes results in a new combination of alleles

Question 6

What is independent segregation of chromosomes?

Answer 6

During first meiotic division, separation of the homologous chromosomes occurring independently of other homologous pairs

Question 7

What is random fertilisation?

Answer 7

Random gametes fusing during sexual reproduction

Question 8

What are the characteristics mainly influenced by genetic factors?

Answer 8

Controlled by one or two gametes, expressed as distinct phenotypes with no intermediates, represented as distinct groups on a bar chart

Question 9

What are the characters influenced by the environment?

Answer 9

Controlled by many genes (polygenic), no separate categories or types but a range of intermediates, produce a curve of normal distribution