Unit 4.1.2 Cell Division Flashcards Preview

11B1 - AQA Biology Trilogy > Unit 4.1.2 Cell Division > Flashcards

Flashcards in Unit 4.1.2 Cell Division Deck (32)
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1

An example of a gamete is a

sperm or egg

2

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

23

3

How many chromosomes are found in an egg or sperm

23

4

Cells undergo cell division called

mitosis

5

Mitosis is important for

growth, repair and replace worn out cells

6

The first step of the cell cycle is

DNA replication - genetic material is doubled

7

A chromosome looks X shaped because

it has replicated

8

In mitosis after DNA replication has occurred what happens next?

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

9

What is the end result of mitosis?

two genetically identical daughter cells

10

What is the meristem?

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

11

What is a stem cell?

A cell that has the capacity to differentiate into ANY cell

12

Inside the nucleus you will find

Chromosomes made from DNA

13

In body cells chromosomes are found in

pairs

14

Cells divide in a series of stages called

the cell cycle

15

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

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

16

The last step of mitosis involves

the cell dividing into two

17

Uses of stem cells include

treatment of diseases e.g. paralysis

18

Ethical issues surrounding stem cell use?

destruction of an embryo

19

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

bone marrow, skin, intestine

20

A limitation of adult stem cells is

they have a limited differentiation capacity

21

What is therapeutic cloning?

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

22

Reasons to clone plants?

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

23

chromosomes are found where in the cell?

nucleus

24

Chromosomes are made from ...

DNA

25

Genes function are to..

determine characteristics

26

Cell cycle is made up from which 2 main stages?

1. growth and DNA replication 2. mitosis

27

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

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

28

Replicated chromosomes look like

X shaped molecules

29

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

the replicated chromosomes are pulled apart (separated)

30

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

2