Reproduction - Inheritance and variation

Question 1

What is Mitosis?

Answer 1

Mitosis is a process of cell division that produces two identical daughter cells.
The DNA is replicated and split into two diploid cells.

Question 2

Explain the process of Meiosis

Answer 2

Meiosis is a type of cell division where a single cell divides twice to produce four non-identical daughter cells, each with haploid chromosomes . This process creates gametes for sexual reproduction.

Question 3

Are the off- springs produced by sexual reproduction genetically identical to the parent and why?

Answer 3

In sexual reproduction, gametes (sperm and egg cells) are produced by meiosis, which introduces genetic variation.
When fertilisation occurs, the DNA from both parents combines, leading to offspring that are not genetically identical to either parent.
This mixing of genetic material from two individuals results in variation in the offspring.

Question 4

Are the off- springs produced by
asexual reproduction genetically identical to the parent and why?

Answer 4

In asexual reproduction, offspring are produced by the parent without the fusion of gametes.
The process involved is usually mitosis, a type of cell division that produces cells with the same genetic material as the parent.
As a result, the offspring are genetically identical to the parent because there is no mixing of DNA from two different individuals.

Question 5

What is the term given to ‘halve’ the number of chromosomes?

Answer 5

Haploid

Question 6

Why do the cells produced in Meiosis have halve the number of chromosomes?

Answer 6

Sex cells(gametes) have haploid cells so that during fertilisation the sperm and egg cell fuse and have the correct diploid cells in the zygote.

Question 7

What is the term given to the ‘full’ number of chromosomes?

Answer 7

Diploid

Question 8

Pros and Cons of sexual reproduction

Answer 8

Pros
- variation produced
- give survival chance to off- springs if
environment changes
- natural selection can be sped up by
selective breeding

Cons
- needs more than one parent
- slower reproduction

Question 9

Pros and Cons of Asexual reproduction

Answer 9

Pros
- needs only one parent
- faster reproduction

Cons
- no variation produces
- doesn’t give survival chance to off-
springs if environment changes
- no natural selection