Cells And Control

Question 1

What is mitosis?

Answer 1

cell division, producing 2 genetically identical diploid body cells

Question 2

What does haploid mean?

Answer 2

Only contains 23 chromosomes

Eg sperm and egg

Question 3

What does diploid mean?

Answer 3

46 chromosomes

Eg animals

Question 4

What is the cell cycle?

Answer 4

Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

Question 5

What happens in interphase?

Answer 5

New subcellular structures are made and dna replicates

Question 6

What happens in prophase?

Answer 6

Nucleus breaks down and spindle fibres begin to form

Question 7

What happens in metaphase?

Answer 7

Spindle fibres attach to the chromosome which then line up in the equator of the cell

Question 8

What happens in anaphase?

Answer 8

Spindle fibres shorten pulling the chromosomes to the poles of the cell

Question 9

What happens in telophase?

Answer 9

Two new nuclei form

Question 10

What happens in cytokinesis?

Answer 10

Cytoplasm splits to form two new cells

Question 11

How can mitosis cause cancer?

Answer 11

When cell division becomes out of control and form lumps of cells called tumours

Question 12

What is cell differentiation?

Answer 12

Stem cells are able to change to become specialised cells

Question 13

What is cell elongation?

Answer 13

Plant cell expands making the cell bigger

Question 14

What happens in animal growth?

Answer 14

Cell division

No elongation

Stop growing when adults

Question 15

What happens in plant growth?

Answer 15

Cell division

Elongation in shoot and root tips

Don’t stop growing

Question 16

What are growth percentile charts used for?

Answer 16

To assess a child’s development over time

Question 17

What are stem cells?

Answer 17

Undifferentiated

Can divide to make more cells or can differentiate into specialised cells

Question 18

Where are plant stem cells found?

Answer 18

Meristem

Question 19

What can embryonic stem cells do?

Answer 19

Become almost any type of cell in the body so the embryo can become a full person

Question 20

Where are adult stem cells found?

Answer 20

Only in certain places in differentiated tissues

Question 21

Adult stem cells can only become…

Answer 21

A small range of cell types

Question 22

How are stem cells used in medicine?

Answer 22

Doctors can make stem cells differentiate into the type of cell that is damaged in the ill person and inject them where they are needed

Also used to test new drugs

Question 23

Why can’t adult stem cells be used to treat every disease?

Answer 23

Difficult to remove

Question 24

Why would taking adult stem cells from the ill person be beneficial?

Answer 24

They are less likely to be rejected by the body’s immune system

Question 25

Why are embryonic stem cells easy to extract?

Answer 25

An embryo is just a ball of cells and can become almost any cell type

Question 26

Why would embryonic stem cells be rejected by the ill person's immune system?

Answer 26

Because it doesn’t come from the ill persons body

Question 27

What is an ethical objection of using an embryonic stem cell?

Answer 27

Catholics believe life begins at fertilisation so it would be seen as murder

Question 28

What is the cns?

Answer 28

Central nervous system Brain and spinal chord

Question 29

What is the peripheral nervous system?

Answer 29

The rest of the body, made up of lots on nerve cells called neurones

Question 30

What is a stimulus?

Answer 30

Change in environment

Question 31

What do neurones do?

Answer 31

Carry electrical signals called impulses to the cns which coordinates the response and sends impulses to effectors which bring about the response

Question 32

What is sending impulses called?

Answer 32

Neurotransmission

Question 33

What is the order of neurotransmission?

Answer 33

``` Stimulus Receptor Sensory neurone Relay neurone Motor neurone Effector Response ```

Question 34

What does the myelin sheath do?

Answer 34

Insulates and speeds up transmission

Question 35

What is a reflex arc and why is it needed?

Answer 35

When we need to react fast, the impulse only goes to your spinal chord, not your brain which makes it faster

Question 36

What is a synapse?

Answer 36

Gaps between neurones

Question 37

What do synapses do?

Answer 37

Convert electrical energy into chemical energy

Question 38

What do neurotransmitters do?

Answer 38

Diffuse across the synapse