Cell division + differentiation

Question 1

What is cell division called?

Answer 1

mitosis

Question 2

Why do cells divide?

Answer 2

-Growth

-Repair

-Replacement

Question 3

What is inside the nucleus?

Answer 3

Chromosomes

Question 4

What do chromosomes do?

Answer 4

Carry genetic information with instructions on how to make new cells.

Question 5

What is a gene?

Answer 5

A section of DNA which controls a characteristic of your body

Question 6

How many chromosomes are in a nucleus?

Answer 6

46 (23 pairs)

Question 7

Where do chromosomes come from in pairs?

Answer 7

One from the mother and one from the father

Question 8

What is the series of stages when a cell divides known as?

Answer 8

The cell cycle

Question 9

What happens after a cell divides?

Answer 9

2 identical daughter cells are made

Question 10

What happens because 2 identical cells are made?

Answer 10

All the chromosomes and genetic information in your body cells are the same.

Question 11

What happens in asexual reproduction?

Answer 11

The cells of the offspring are produced by mitosis from the cells of the parent. This is why they contain the exact same genes as their parent.

Question 12

What happens to the speed of the cell cycle?

Answer 12

-It can vary from <24hrs to >1yr

Question 13

What happens to the speed of the cell cycle with age?

Answer 13

As an animal ages, the speed of the cell cycle slows as new cells are not needed as often when an animal stops growing.

Question 14

What are examples of regions that continue to quickly grow, even in adulthood?

Answer 14

-Hair follicles

-Skin

-Blood

-Digestive system lining

Question 15

How many stages are in the cell cycle?

Answer 15

3

Question 16

What is stage 1 of the cell cycle?

Answer 16

-The cell grows bigger and replicates DNA to form 2 copies of each chromosome

-More sub-cellular structures are made such as mitochondria, ribosomes and chloroplasts

-The cell continues its normal activities during this process

Question 17

What is stage 2 of the cell cycle?

Answer 17

mitosis - one set of chromosomes is pulled to each end of the dividing cell and the nucleus divides.

Question 18

What is stage 3 of the cell cycle?

Answer 18

This is the stage during which the cytoplasm and the cell membranes also divide to form two identical daughter cells.

Question 19

Why do children gain cells?

Answer 19

Mitotic divisions produce cells faster than old cells die

Question 20

Why do adults not gain or lose cells?

Answer 20

Cell death and mitosis stay in balance

Question 21

Why do old people show signs of ageing?

Answer 21

Mitosis slows down

Question 22

What is a stem cell?

Answer 22

A cell that can differentiate into any cell type that is needed

Question 23

What is a specialised cell?

Answer 23

A cell with different sub-cellular structures to carry out specific functions

Question 24

Whats an example of a type of cell that is grown/replaced by mitosis?

Answer 24

Muscle

Question 25

Whats are examples of types of cells that are grown/replaced by stem cells?why?

Answer 25

-Red blood

-Skin

-This is because they cannot divide

Question 26

What is a type of cell that doesn’t divide or get replaced by stem cells?

What is the impact of this on this type of cell?

Answer 26

-Nerve cells

-When they are damaged, they are not usually replaced.

Question 27

How long do plant cells differentiate for?

Answer 27

All their lives

Question 28

Where are undifferentiated cells formed in plants?

Answer 28

Formed at active (growing) regions of the stems and roots, known as meristems

Question 29

What happens if you move a plant cell to a different part of a plant?

Answer 29

It redifferentiates and becomes a different type of cell

Question 30

What is the word for producing identical offspring?

Answer 30

Cloning

Question 31

What type of organism is easy to clone?

Answer 31

Plants

Question 32

What type of organism is hard to clone?

Answer 32

Animals

Question 33

How are plant clones made?

Answer 33

Take a piece of tissue from the plant and, under the right conditions, the cells will become unspecialised and multiply by mitosis, these will then differentiate and form new plant organs, eventually becoming a whole plant that is identical to the parent.