Unit 4.1.2 Cell Division

Question 1

An example of a gamete is a

Answer 1

sperm or egg

Question 2

How many chromosome pairs are found in the nucleus of a body cell?

Answer 2

23

Question 3

How many chromosomes are found in an egg or sperm

Answer 3

23

Question 4

Cells undergo cell division called

Answer 4

mitosis

Question 5

Mitosis is important for

Answer 5

growth, repair and replace worn out cells

Question 6

The first step of the cell cycle is

Answer 6

DNA replication - genetic material is doubled

Question 7

A chromosome looks X shaped because

Answer 7

it has replicated

Question 8

In mitosis after DNA replication has occurred what happens next?

Answer 8

Replicated chromosomes line up and then separate, the cell then divides into two

Question 9

What is the end result of mitosis?

Answer 9

two genetically identical daughter cells

Question 10

What is the meristem?

Answer 10

An area in the plant in which rapid cell division is occurring - usually roots and shoots

Question 11

What is a stem cell?

Answer 11

A cell that has the capacity to differentiate into ANY cell

Question 12

Inside the nucleus you will find

Answer 12

Chromosomes made from DNA

Question 13

In body cells chromosomes are found in

Answer 13

pairs

Question 14

Cells divide in a series of stages called

Answer 14

the cell cycle

Question 15

Before the cell divides what does the cell need to do?

Answer 15

increase in size (grow) and increase the number of mitochondria and ribosomes (and replicate its DNA)

Question 16

The last step of mitosis involves

Answer 16

the cell dividing into two

Question 17

Uses of stem cells include

Answer 17

treatment of diseases e.g. paralysis

Question 18

Ethical issues surrounding stem cell use?

Answer 18

destruction of an embryo

Question 19

There are other sources of stem cells which don’t involve using an embryo, they are?

Answer 19

bone marrow, skin, intestine

Question 20

A limitation of adult stem cells is

Answer 20

they have a limited differentiation capacity

Question 21

What is therapeutic cloning?

Answer 21

An embryo is created using the genes of the patients, this way the stem cells from the embryo are not rejected

Question 22

Reasons to clone plants?

Answer 22

rare species can be cloned to protect from extinction and crops with special features e.g. disease resistance can be cloned.

Question 23

chromosomes are found where in the cell?

Answer 23

nucleus

Question 24

Chromosomes are made from …

Answer 24

DNA

Question 25

Genes function are to..

Answer 25

determine characteristics

Question 26

Cell cycle is made up from which 2 main stages?

Answer 26

1. growth and DNA replication 2. mitosis

Question 27

In the cell cycle why does the cell need to grow?

Answer 27

Increase the amount of internal structures for the NEW cell (mitochondria/ribosomes)

Question 28

Replicated chromosomes look like

Answer 28

X shaped molecules

Question 29

In mitosis the replicated chromosomes line up in the centre of the cell, what happens next?

Answer 29

the replicated chromosomes are pulled apart (separated)

Question 30

In mitosis how many new cells are produced after 1 division if you start with 1 cell.

Answer 30

2

Question 31

The types of cell division that produces genetically identical cells

Answer 31

mitosis

Question 32

What has happened for the chromosome to now appear as an X shaped structure?

Answer 32

its replicated (part of cell cycle)