sb2 cells and control (paper 1)

Question 1

what are the stages of mitosis

Answer 1

• prophase
• metaphase
• anaphase
• telophase

Question 2

(for mitosis) what happens in prophase ?

Answer 2

• chromosones are condensed

Question 3

(for mitosis) what happens in metaphase ?

Answer 3

• chromosones line up in the middle

Question 4

(for mitosis) what happens in anaphase ?

Answer 4

• the chromosones are pulled apart by spindle fibres

Question 5

(for mitosis) what happens in telophase ?

Answer 5

• the cell NUCLEI splits into two, resulting in two diploid daughter cells

Question 6

what is the main state a cell goes under

Answer 6

interphase

Question 7

what happens in interphase

Answer 7

when the cell does it’s normal activities, and duplicates dna
- it is NOT part of the process of mitosis !!

Question 8

what happens after telophase

Answer 8

cytokinesis

Question 9

what happens in cytokinesis

Answer 9

• when the actual CELL splits into two

Question 10

what causes tumours

Answer 10

uncontrollable cell division

Question 11

what can unctrolled cell division result in

Answer 11

tumours

Question 12

what are the two types of tumours

Answer 12

cancerous and non cancerous

Question 13

what makes a tumour cancerous

Answer 13

the fact that it can move around the body and attatch itself to another part of the body

Question 14

what does CNS stand for

Answer 14

central nervous system

Question 15

what are the parts of CNS

Answer 15

the brain and spinal cord

Question 16

what are the three neurons/nerve cells part of the cns

Answer 16

sensory, motor and relay

• note : neurons and nerve cells are synonyms

Question 17

what is a reflex arc

Answer 17

an action responding to a stimuli that doesn’t require the brain

(e.g moving your hand away after touching something hot)

Question 18

what is a synapse

Answer 18

the gap between two neurons

Question 19

what is the gap between two neurons called ?

Answer 19

the synapse

Question 20

describe what happens when an electrical impulse travels between a neuron to the next neuron (between the synapse)

Answer 20

• it travels as an electrical impulse
• as it reaches the end of the neuron, the electrical impulse turns into a chemical
• it travels as a chemical in the synapse
• it’s then recieved by receptors from the next neuron, then turned back into an electrical impulse

Question 21

what is a stimuli

Answer 21

a change in the environment

Question 22

explain how our CNS responds to a stimuli

Answer 22

• the relay neurons recieves the signal and passes it onto the sensory neuron
• the sensory neuron recieves the signal (our five senses) and passes it onto the motor neurons
• the motor neurons are connected to the muscle, which allows us to have a physical response

Question 23

what are the four main components of the brain ?

Answer 23

• cerebral cortex
• cerebellum
• medulla oblongata
• hypothalamus

Question 24

in the brain, what is the cerebral cortex

Answer 24

• outer layer of the brain divided into two hemispheres
• high order processes such as intelligence, memory, consciousness, and personality

Question 25

in the brain, what is the cerebellum

Answer 25

- under cerebral cortex - balance, muscle coordination and movement

Question 26

in the brain, what is the medulla oblongata

Answer 26

- unconscious activities - heart rate and breathing

Question 27

in the brain, what is the hypothalamus

Answer 27

regulates temperature and water balance within the body

Question 28

in the eye, what are cataracts

Answer 28

when protein builds up in the lens and makes your vision blurry

Question 29

in the eye, how can you fix cataracts

Answer 29

replace the lens with plastic

Question 30

in the eye, what is being short sighted

Answer 30

when the eye is short so the image is focused behind the retina

Question 31

in the eye, how can you fix being short sighted

Answer 31

correction by a diverging lens to spread out rays before reaching the eye

Question 32

in the eye, what is being long sighted

Answer 32

when they eye is too long so the image is focused in front of the retina

Question 33

in the eye, how can you fix being long sighted

Answer 33

correction by a converging lens to bend rays before they reach the eye

Question 34

in the eye, what is being colour blind

Answer 34

when the eyes have some cones that do not work properly, the most common form is red-green

Question 35

in the eye, how can you fix being colour blind

Answer 35

you can't lol

Question 36

what is a meristem

Answer 36

- the parts of a plant where cell division/mitosis is happening quickly near the end of each shoot - the root allows plants to continue growing through their life

Question 37

how can we measure growth

Answer 37

- taking measurements or mass - it is NOT when we become a fatty when consuming food

Question 38

is mitosis sexual or asexual

Answer 38

asexual

Question 39

what are the stages of growth in plants

Answer 39

- cell division/mitosis: when cells divide quickly - elongations: when cells increase in length - differentiation: when cells differentiate into specialised cells that have different functions

Question 40

why is cell differentiation important for the growth of plants

Answer 40

it allows cells to specialise and perform specific functions in an organism

Question 41

what is cell differentiation

Answer 41

when new cells may change in different ways resulting them becoming specialised for different functions

Question 42

give an example of a specialised plant cell

Answer 42

palisade cell - have many chloroplasts in cytoplasm to capture energy from light for photosynthesis

Question 43

why can brain tumours be hard to treat

Answer 43

- protected by the skull - difficult to access - the nerves don't regenerate