Inherited Change

Question 1

Explain what is meant by homologous chromosomes.

Answer 1

It is a pair of chromosomes that have the same structure as each other with the same genes (not necessarily the same alleles) at the same loci and that pair together to form ambivalent during the first division of meiosis.

Question 2

Explain the meaning of haploid.

Answer 2

A haploid cells is a cell that contains one complete set of homologous chromosomes.

Question 3

Explain what is meant by diploid cell.

Answer 3

It is a cell that possess 2 complete sets of chromosomes.

Question 4

Explain the need for reduction division.

Answer 4

1. Meiosis
2. The cell has only 1 set of chromosomes rather than 2
3. To allow for sexual reproduction where fertilisation will take place
4. Prevent the chromosome number from doubling each generation
5. Needed to ensure genetic variation

Question 5

Where does spermatogenesis occur?

Answer 5

Tubules of the testes

Question 6

Describe the process of spermatogenesis.

Answer 6

1. Diploid cell divides to form spermatogonia
2. This grows to form the primary spermatocyte
3. This undergoes mitosis to form a haploid secondary spermatocytes
4. Meiosis 2 causes spermatids which mature into spermatozoa.

Question 7

How does oogenesis differ from spermatogenesis?

Answer 7

1. Much fewer gametes are produced
2. The process takes much longer with waiting stages
3. Takes place inside the ovaries and not testes
4. Starts when the girl is born and proceeds after puberty.

Question 8

How does oogenesis occur?

Answer 8

Diploid cell divides by mitosis to form oogonia
Meiosis starts and stops at prophase 1 to form primary oocytes
This is before birth
Polar body released and the secondary oocyte is produced after meiosis
Released every month.