3 - Genetics - Asexual & Sexual Reproduction

Question 1

What is sexual reproduction?

Answer 1

Where genetic information from two organisms (father and mother) combine to produce offspring that are genetically different from each parent

Question 2

What are gametes?

Answer 2

Reproductive cells (like sperm/egg) that contain half the number of chromosomes of normal cells, called haploids

Question 3

What is Meiosis?

Answer 3

A type of cell division that doesn't produce identical cells (gametes)
Only happens in the reproductive organs in humans

Question 4

What happens during the first division of Meiosis?

Answer 4

1) The cell duplicates its DNA before it starts to divide
2) The chrms line up in the centre in pairs which are then pulled apart so each new cell only has one copy of each chrms
3) Some of the father’s chrms and some of the mothers chrms go into each new cell, giving that cell a mix of the chromosomes creating genetic variation

chrms = chromosome

Question 5

What happens during the second division of Meiosis?

Answer 5

1) Chrms line up in the centre and the arms are pulled apart
2) You get four haploid daughter cells aka gametes
3) Each gamete only has a single set of chrms, making them all genetically different

chrms = chromosome

Question 6

What is the difference between asexual and sexual reproduction?

Answer 6

Asexual - cells divide by mitosis resulting in two diploid daughter cells
Sexual - cells divide by miosis resulting in two genetically different haploid gametes which fuse to form a diploid cell

Question 7

What are some advantages of asexual reproduction?

Answer 7

— Can produce lots of offspring very quickly as the reproductive cycle is very fast
— Only one parent is needed - organisms can reproduce in favourable conditions whenever without having to wait for a mate

Question 8

What are some advantages of sexual reproduction?

Answer 8

— Creates genetic variation in the population so some individuals will have different characteristics
— This variation means the species have better chance of survival if environmental conditions suddenly change and can also lead to natural selection and evolution

Question 9

What are some disadvantages of asexual reproduction?

Answer 9

— Lack of genetic variation so if the environment changes the whole population may be affected

Question 10

What are some disadvantages of sexual reproduction?

Answer 10

— Two parents are needed which can be a problem if individuals are isolated
— Takes more time and energy, resulting in fewer offspring
— Finding and attracting mates also takes time & energy