DNA Replication, Mitosis, Meiosis

Question 1

In what stage of the cell cycle does cell checking and repair occur?

Answer 1

G2

Question 2

In what stage of the cell cycle does DNA replication occur?

Answer 2

S

Question 3

In what stage of the cell cycle does cell division occur?

Answer 3

M

Question 4

What enzyme is used to catalyse DNA replication?

Answer 4

DNA polymerase

Question 5

In what direction does the new chain in DNA replication grow?

Answer 5

5’ to 3’

Question 6

What is required for DNA replication to start?

Answer 6

Primase- to create a primer strand

Question 7

In what stage of the cell cycle does cell content replication occur?

Answer 7

G1

Question 8

What are the names of the 2 newly formed strands of DNA in replication?

Answer 8

Leading strand

Lagging strand

Question 9

Why is the lagging strand not continuous and what is the name given to the fragments?

Answer 9

DNA is made from 5’ to 3’. As the DNA unwinds, small chains of DNA are made. These are called Ozazaki fragments.

Question 10

Which enzyme connects Ozazaki fragments?

Answer 10

DNA ligase

Question 11

Which enzyme unwinds the DNA alpha helix?

Answer 11

DNA helicase

Question 12

How many DNA molecules are in a chromosome?

Answer 12

1

Question 13

What is mitosis?

Answer 13

Cell division in somatic cells to produce 2 identical daughter cells

Question 14

What happens in prophase?

Answer 14

The nuclear membrane breaks down and spindle fibres appear

Question 15

What happens in Prometaphase?

Answer 15

A kinetochore attached to the centromere is attached to the spindle fibres

Question 16

What happens in Metaphase?

Answer 16

The chromosomes line up randomly in the centre of the cell. The spindle fibres are polar.

Question 17

What happens in Anaphase?

Answer 17

The chromatids separate as they are pulled by the spindle fibres

Question 18

What happens in Telophase?

Answer 18

2 nuclear membranes form around each group of chromosomes. The cytoplasm starts to split.

Question 19

What is meiosis?

Answer 19

A special type of cell division for germ line cells. It produces 4 non-identical, haploid cells.

Question 20

In meiosis, at what stage does crossing over occur?

Answer 20

Metaphase I

Question 21

Name the products at the 4 steps of spermatogenesis

Answer 21

1 Spermatogonium
1 Primary spermatocyte
4 Spermatids
4 Mature sperm

Question 22

Name the products at the 3 stages of oogenesis

Answer 22

1 Oogonium
1 Primary Oocyte
3 Polar bodies + 1 Mature Ovum