Unit 2 Producing New Cells And Reproduction

Question 1

Describe the process of mitosis.

Answer 1

1. The chromosomes become visible
2. Chromosomes/chromatids move to/line up at/across the equator.
3. Spindle (fibres) form /attach/contract/shorten/pull.
4. (Pairs of) chromatids are separated/pulled apart.
5. Chromosomes move to poles/opposite ends of cell.
6. Nuclear membrane(s) form/develop.
7. Cytoplasm divides/splits.

Question 2

What does mitosis do?

Answer 2

Mitosis provides new cells for growth and repair of damaged cells and maintains the diploid chromosome compliment.

Question 3

What are stem cells?

Answer 3

Stem cells in animals are unspecialised cells which can divide in order to self-renew.
They have the potential to become different types of cell.
Stem cells are involved in growth and repair.

Question 4

What does specialisation of cells lead to?

Answer 4

It leads to the formation of a variety of cells, tissues and organs. Groups or organs; which work together to form systems.

Question 5

What is the hierarchy?

Answer 5

-cells
-tissues
-organs
-systems

Question 6

Cells are ——, except ——, which are ——.

Answer 6

Cells are diploid, except gametes, which are haploid.

Question 7

What is fertilisation?

Answer 7

The fusion of the nuclei of the two haploid gametes to produce a diploid zygote, which divides to form an embryo.

Question 8

What are diploid cells?

Answer 8

All body cells have two sets of matching chromosomes - one set from the mother and one from the father. These cells are known as diploid cells.

Question 9

What are haploid cells?

Answer 9

Sex cells (gamete cells) have only one set of chromosomes. These cells ra e known as haploid cells.

Question 10

What is a gamete?

Answer 10

A haploid sex cell.
Stem and eggs are gametes.

Question 11

What are the male sex cells in plants and animals?

Answer 11

Sperm - small cell with a tail to allow it to swim. The nucleus is in the head and it’s haploid. It is produced in the testes.
pollen - produced in the anthers

Question 12

What are the female sex cells in plants and animals?

Answer 12

Egg - large cell, contains food store and haploid nucleus. Produced in the ovary
Ovule - produced in ovary

Question 13

What is the oviduct?

Answer 13

Site of fertilisation in humans.

Question 14

What is a zygote?

Answer 14

Diploid fertilised egg that will develop into the embryo.