Inheritance, variation and evolution

Question 1

Give one difference between mitosis and meiosis.

Answer 1

Mitosis leads to genetically identical cells being formed while meiosis leads to non- genetically identical cells being formed.

Question 2

What does sexual reproduction involve?

Answer 2

The joining (fusion) of male and female gametes.

Question 3

Give examples of male and female gametes.

Answer 3

-Sperm and egg cells in animals

-Pollen and egg cells in flowering plants

Question 4

What does the mixing of genetic information lead to in sexual reproduction?

Answer 4

Variety in the offspring.

Question 5

What does the formation of gametes involve?

Answer 5

Meiosis

Question 6

What does asexual reproduction involve?

Answer 6

Only one parent and no fusion of gametes.

Only mitosis.

Question 7

Why does asexual reproduction lead to genetically identical offspring?

Answer 7

There is no mixing of genetic information hence genetically identical offspring.

Question 8

Explain how meiosis halves the number of chromosomes in gametes (sex cells).

Question 9

Explain how fertilisation restores the full (normal) number of chromosomes.

Question 10

Cells in reproductive ______ divide by ______ to form ________.

Answer 10

organs
meiosis
gametes

Question 11

Explain what happens when a cell divides to form gametes.

Answer 11

-copies of the genetic information are made (chromosomes duplicate)

-the cell divides twice to form four gametes, each with a single set of chromosomes

-all gametes are genetically different from each other.

Question 12

What does the new cell formed by the fusion of two gametes (zygote) do?

Answer 12

Divide by mitosis.

This causes the total number of cells to increase, forming a ball of cells called an embryo.

As the embryo develops, cells differentiate.