Genetics: Genetic Diversity - Diploid Cells, Gametes & Fertilisation

Question 1

What are diploid body cells?

Answer 1

• Normal body cells have diploid number of chromosomes (2n)

- Each cell contains two of each chromosome - one from mum, one from dad

Question 2

What are haploid body cells?

Answer 2

• Gametes that have a haploid number of chromosomes (n)

- Only contain one chromosome from each homologous pair

Question 3

What is a homologous pair of chromosomes?

Answer 3

• 2 chromosomes that are the same size
• 2 chromosomes that carry the same genes (may have different alleles)
• These genes are in the same position or locus on the chromosome

Question 4

What happens during fertilisation?

Answer 4

• Haploid sperm fuses with haploid egg, making a diploid zygote
• Half of chromosomes from mum, half from dad
• New combinations of alleles are made, increasing genetic diversity