Fertilisation and Genetics

Question 1

what does the flagellum help the sperm do?

Answer 1

move them through water - some male fish release their sperm into the water where they live

Question 2

how often are eggs produced and from where?

Answer 2

eggs are produced monthly from the ovaries

Question 3

are women born with eggs?

Answer 3

yes

Question 4

are men born with sperm?

Answer 4

no - they start producing them in puberty

Question 5

what is external fertilisation?

Answer 5

1. in fish, the females release their ova into the water and the sperm have to swim through the water to fertilise the ova
2. this kind of fertilization takes place outside the body

Question 6

what is internal fertilisation?

Answer 6

1. other males animals including birds and mammals, ejaculate their sperm in a special fluid called semen, into the bodies of the females during sexual intercourse
2. internal fertilization then takes place inside the females body
3. fertilization is much more likely
4. once the sperm has reached the ovum, its nucleus must enter the ovum and fuse with the ovum nucleus

Question 7

how many chromosomes does a normal human body cell have (not red blood cell or gametes)?

Answer 7

46 - 23 pairs of homologous chromosomes

Question 8

what is a diploid cell?

Answer 8

a cell that has two sets of chromosomes (maternal and paternal) and has 46 chromosomes in total

Question 9

what is a haploid cell?

Answer 9

a cell with only half the genetic information required

Question 10

what happens when a haploid egg and a haploid sperm fuse?

Answer 10

fertilisation has occurred to form a diploid cell

Question 11

what is the first cell formed at fertilisation celled?

Answer 11

zygote

Question 12

how many chromosomes does a zygote have?

Answer 12

46 - it is produced after fertilization

Question 13

fertilisation definition

Answer 13

the fusion of haploid male and female gametes, restoring the diploid number of chromosomes in the zygote