Genetic diversity can arise as a result of mutation or during meiosis

Question 1

Mutation

Answer 1

Change in the sequence of base pairs in a DNA molecule that may result in an altered polypeptide

Question 2

Effects of gene mutation

Answer 2

They can arise spontaneously during DNA replication and include base deletion and base substitution

Question 3

Mutagenic agents

Answer 3

Increase rate of gene mutation

Question 4

How can mutations occur during meiosis?

Answer 4

Mutations in the number of chromosomes can arise spontaneously by chromosome non-disjunction

Question 5

Process of meiosis

Answer 5

• 1st meiotic division
• Homologous chromosomes pair up & wrap around each-other at bivalent
• Pressure builds & thus equivalent portions of chromatids may break off either chromosome & be exchanged
• Homologous pairs separated by end of division via pulling apart with spindle fibres
• 1 chromosome from each pair enters 1 of 2 daughter cells

Question 6

Expression used to calculate the possible number of different combinations of chromosomes following meiosis, without crossing over

Answer 6

2n