Topic 7 - Sexual Reproduction and Meiosis

Question 1

what is the definition of sexual reproduction?

Answer 1

sexual reproduction involves the fusion of male and female gametes. Because there are two parents, the offspring contain a mixture of the parent’s genes.

Question 2

what do the mother and father produce in sexual reproduction?

Answer 2

gametes - sperm and egg cells

Question 3

are gametes haploid or diploid?

Answer 3

haploid - they contain 23 chromosomes

Question 4

what happens at fertilisation?

Answer 4

a male gamete fuses with a female gamete to form a zygote

Question 5

how does a zygote develop?

Answer 5

it undergoes mitosis to form an embryo

Question 6

what is the definition of meiosis?

Answer 6

cell division that produces four haploid cells whose chromosomes are not identical

Question 7

where does meiosis happen in humans?

Answer 7

in the reproductive organs

Question 8

how many divisions are there in meiosis?

Answer 8

2

Question 9

what happens in division 1 of meiosis?

Answer 9

1. the cell duplicates its DNA into x-chromosomes. one arm of each chromosome is an exact copy of the other arm
2. chromosomes line up in pairs in the middle of the cell. one chromosome in the pair came from the mother and the other came from the father.
3. the pairs are pulled apart, and each new cell has a mixture of the mother and fathers chromosomes

Question 10

what happens in division 2 of meiosis?

Answer 10

1. chromosomes line up again in the centre of the cell. the arms of the chromosomes are pulled apart
2. you get four haploid gametes, which are all genetically different