Topic 2

Question 1

problems with chemotherapy

Answer 1

can kill heathy cells like hair cells
blood brain barrier so not all drugs get through

Question 2

problems with radiotherapy

Answer 2

x-rays pass through healthy tissue until it reaches the desired cells

Question 3

problems with brain surgery

Answer 3

skull protects the brain making it hard to assess
some cancer cells may be left behind

Question 4

cell division

Answer 4

when a cell divides by mitosis for growth and repair

Question 5

elongation

Answer 5

when a cell becomes larger by absorbing water into the vacuole (only in plants)

Question 6

differentiation

Answer 6

when a cell speciallises to a spesific function

Question 7

using stem cells in medicine

Answer 7

repairs damages tissues of diseased organs
test drugs and tehn on humans if theyre safe

Question 8

risks of stem cells

Answer 8

• may be rejected if they are taken from another peron’s body
• ethical issues since its using embryos which coudl potentially lead to human life)

Question 9

impulse of touching a hot object

Answer 9

The stimulus is the change in temperature. The receptors in the skin pick up on teh chnage in temperature. An electrical impulse is carried along the sensory neurone to teh motor neurone in teh spinal chord. The impulse is taken to your hand and teh responce is to take it off teh hot object.

Question 10

axon

Answer 10

fibre that moves electrical impulses away from the cell body

Question 11

dendron

Answer 11

fibre that moves electrical impulses towards the cell body

Question 12

myetlinth sheath

Answer 12

goes around and insulates the fibres and speeds up the electrical impulse

Question 13

sensory neurone

Answer 13

carries impulses to the motor neurone in teh spine

Question 14

motor neurone

Answer 14

in teh spine, carries impusle to the relay neuroen

Question 15

relay neruone

Answer 15

impulse to teh effector musle/ gland

Question 16

synapses

Answer 16

gap between two neurones
when an electrical impulse reaches a synapse, it causes teh relaese of a chemical called nerotransmitter
teh chemiscal diffuses over teh synapse and binds to teh receptors
Starts teh impuse to teh next neurone

Question 17

fertiisation

Answer 17

haploid agg cell fuses witha haploid sperm cell to form a diploid zygote

Question 18

haploid

Answer 18

23

Question 19

diploid

Answer 19

46

Question 20

interphase

Answer 20

• chromosones not cleraly visale
• new organells made
• dna replicates

Question 21

prophase

Answer 21

-chromosones condence
-nucleur membrane breaks down
- spindle fibres form

Question 22

metaphase

Answer 22

• chrmosones line up in teh middle of teh cell
• chromosones attach to spinde fibres by thier centromiters

Question 23

anaphase

Answer 23

• chromosones are pulled apart to opposite ends of teh cell
• spindle fibres shorten

Question 24

telophase

Answer 24

• chromosones unravel
• nuclear membrane reforms
• chromosones now enclosed in 2 seperate nucli

Question 25

cancer

Answer 25

when a single heathy human cell ungeoes a mutation tumor cells - mutation divide rapidly and uncontrollably which can led to death

Question 26

causes of cancer

Answer 26

x-rays uv lights cigarette smoke genes

Question 27

embryonic stem cells

Answer 27

only found in embryos (blastocyst) can differentiate into any cell in th body

Question 28

cerebral conrtex

Answer 28

used for most sences, language, meomory, intelligance

Question 29

cerebellum

Answer 29

fine musle movments, balance, posture

Question 30

medulla oblongata

Answer 30

involuntary activities like heart rate and breathing rate

Question 31

plant growth

Answer 31

mainly at teh shoot/root tips and meristems increase in size by elongation pf cells as the vacuole absorbs water and mitosis

Question 32

animal growth

Answer 32

growth in most tissues and cells mitosis

Question 33

CAT scan

Answer 33

x- ray pictures are taken from different angles of the brain forming a 3D image making it easier to see the tumpur denser matericals liek the tumpur will absorb more x-rays causing whiter areas

Question 34

PET SCAN

Answer 34

patient is injected with a radioactive tracer attached to glucose the more active cells liek cancer cells take in more glucose the radioactive substance decays and releases gamma rays they are detected

Question 35

both scans can

Answer 35

- tell us information about the size, shape, and location of teh tumour

Question 36

Advantges of useing scans instead of surgery

Answer 36

- less expensve - no risk damaging brian in scan - the scan will show the tumour acurately

Question 36

Advantges of useing scans instead of surgery

Answer 36

- less expensve - no risk damaging brian in scan - the scan will show the tumour acurately

Question 37

stimulus

Answer 37

change in the environment

Question 38

cornea

Answer 38

transparent layer at the front of the eye that refracts light into the eye

Question 39

pupil

Answer 39

hole taht allows light into teh eye

Question 40

iris

Answer 40

coloured part of eye that controls teh amount of light entering

Question 41

lens

Answer 41

refracts light into the eye

Question 42

retina

Answer 42

layer at teh back of the eye contains rods (light intensity) and cones (coloured light)

Question 43

optic nerve

Answer 43

contains sensory neurones that carry impulses from receptors to the brain

Question 44

accomodiation

Answer 44

the ability to focuus on near/ distant objects

Question 45

long/ short sightedness can also be cured with

Answer 45

lazer eye surgery which reshapes the cornaea

Question 46

short-sighted

Answer 46

can't focus of distat objects very well the light focuses in front of teh retina because teh eyeball is too long or teh lens is too curved this is corrected by sing a concave/ diverging lens

Question 47

long sighted

Answer 47

person can't focus of close objects

Question 48

laser eye surgery

Answer 48

replaces lens with a plastic one

Question 49

Explain how the size of the pupil of the eye changes when a torch is shone into the eye of a person.

Answer 49

pupil gets smaller iris gets bigger

Question 50

75th percentile

Answer 50

75% of baies weigh less 25 % more

Question 51

why is there no current cure for colourblindness

Answer 51

cant replace the cones

Question 52

pupil diallation

Answer 52

cirular mesle relaxes radial muscle contracts

Question 53

pupil constriction

Answer 53

circular musles contract radial musle relaxes

Question 54

distant object

Answer 54

lens : thin curvature ciliary muscle: relaxes suspensory ligaments: pulled tight

Question 55

high conentraction of cones in the

Answer 55

fovea most light is focused