4.6.1.1 sexual and asexual reproduction

Question 1

How many pairs of chromosomes do humans have?

Answer 1

23 pairs (46 chromosomes)

Question 2

What is asexual reproduction?

Answer 2

a mode of reproduction in which a new offspring is produced by a single parent. The new individuals produced are genetically and physically identical to each other, i.e., they are the clones of their parents.

Question 3

State examples of asexual reproduction where
a) the individual is split in two
b) a part of the individual divides

Answer 3

a) amoeba, bacteria
b) hydra, starfish

Question 4

What are the four stages to asexual reproduction?

Answer 4

Amoeba divides after it has grown to a certain size
The pseudopodia are pulled in and the nucleus divides.
The cell body begins to divide when the nucleus has split.
Two daughter amoebae have been formed

Question 5

What is sexual reproduction?

Answer 5

involves the joining of two sex cells, or gametes. During fertilisation the joining of a male and female gamete occurs to produce offspring which is genetically identical to both parents.

Question 6

Compare asexual and sexual reproduction

Answer 6

Asexual:
- one parent
- all clones from parent
- doesn’t need sex cells
- individual splits in two
- d.g amoeba, starfish
Sexual:
-two parents
- each parent produces half the genes in an gamete
-offspring inherits different features from each parent
-sex cells involved
-same species sex