b3

Question 1

whats the role of neurones

Answer 1

to carry electrical impulses

Question 2

whats a synapse

Answer 2

a gap in-between two neurones. When electrical impulse reaches the end of the neurone chemicals are released to trigger an electrical impulse in the next neurone

Question 3

whats the CNS made of

Answer 3

brain and the spinal chord

Question 4

what are the receptors

Answer 4

what detect the stimuli of an incident

Question 5

whats a sensory neurone

Answer 5

carry information from the receptor to the CNS

Question 6

whats a motor neurone

Answer 6

take information from CNS to the effectors

Question 7

what are the effectors

Answer 7

muscle or glands which provides a reaction

Question 8

what are the relay neurones

Answer 8

inside the spinal chord, what transfers sensory neurones to motor neurones

Question 9

whats the function of the cerebral cortex (cerebrum) and wheres it located

Answer 9

outer wrinkly bit, responsible for consciousness, intelligence, memory, language and senses

Question 10

whats the function of the hypothalamus and wheres it located

Answer 10

small part inner brain, responsible for maintaining body temp, and produces hormones which control the pituitary gland

Question 11

whats the function of the medulla and wheres it located

Answer 11

stem of brain - respnsible for unconscious control, e.g. breathing and heart rate

Question 12

whats the function of pituitary gland and where’s is located

Answer 12

small tic-tac bit, gland that produces many important hormones

Question 13

whats the function of the cerebellum and wheres it located

Answer 13

back wrinkly bit of the brain, responsible for muscle co-ordination and muscle co-ordination

Question 14

how do scientists study the brain

Answer 14

study people with brain damage
electronically stimulate different parts of the brain scan the brains using machines, e.g. CT and MRI

Question 15

what are problems associated with studying the brain

Answer 15

if a person is severely brain damaged it may be seen as unethical as they may not be able to give consent
relies on people who have died and donated the brain to study it
can be difficult to study the brain because MRI scanner may cause the brain to alter

Question 16

what are problems associated with treating the brain

Answer 16

hard to repair damage done
if problem occurs which is hard to access it can be heart to treat, e.g. tumour inside the brain
can leave permanent damage

Question 17

whats the role of the cornea

Answer 17

to refract (bend) light entering the eye

Question 18

whats the role of the iris

Answer 18

to control how much light enters the pupil

Question 19

whats the ciliary body and what does it do

Answer 19

contains ciliary muscles which are attached to the ciliary ligaments and work together t alter the shape of the lens

Question 20

whats the role of the retina

Answer 20

light sensitive, contain receptors called rods and cones which detect light

Question 21

whats the role of the rods

Answer 21

more sensitive in dim light but can’t sense colour

Question 22

whats the role of the cones

Answer 22

colour sensitive, not so good in dim light

Question 23

whats the role of the optic nerve

Answer 23

carry’s impulses from receptors to brain

Question 24

whats the role of the fovea

Answer 24

the point at which light focuses on the retina

Question 25

how does the ciliary body work together to look at distant objects

Answer 25

ciliary muscles relax which allow suspensory ligaments to be pulled taught pulls lens into less rounded, short thick shape so light is refracted less

Question 26

how does the ciliary body work together to look at close objects

Answer 26

ciliary muscles contract which causes the suspensory ligaments to slacken, causing long thin shape of lens so light is refracted more

Question 27

what is long sightedness and how do you fix it

Answer 27

unable to focus on near objects fixed with a convex lens

Question 28

what is short sightedness and how do you fix it

Answer 28

unable to focus on distant objects, fixed with concave lens or can be fixed with corneal laser surgery

Question 29

what happens when the eye constricts and why does it happen

Answer 29

eye becomes smaller when the eye is exposed to bright light. Radial muscle relaxes and the circular muscles contract

Question 30

what happens when the eye dilates and why does it happen

Answer 30

eye becomes bigger to let in more light. Radial muscle contracts and the circular muscles relax

Question 31

what are the different types of glands

Answer 31

pituitary gland adrenal gland thyroid gland pancreas testes ovaries

Question 32

what does the pituitary gland do

Answer 32

near the brain consists of different hormones which either tell the body what do or tell other glands to release their hormones through negative feedback

Question 33

what does the thyroid gland do

Answer 33

in the neck releases thyroxine which regulates metabolism and is important in growth and development. When more thyroxine is released, increased metabolism rate

Question 34

what do the adrenal glands do

Answer 34

just above the kidneys, releases adrenaline which prepares body for a fight or flight reaction

Question 35

what does the pancreas do

Answer 35

just below the kidney, produces insulin which regulates glucose levels

Question 36

what do the testes do

Answer 36

release testosterone and sperm

Question 37

what do the ovaries do

Answer 37

produces oestrogen which is responsible for puberty and the menstrual cycle and produces eggs

Question 38

how is negative feedback used to control thyroxine levels

Answer 38

when thyroxine levels are too high thyroxine inhibits the rate of TSH , this means less thyroxine is released and thyroxine levels return to normal. this is known as negative feedback

Question 39

how do changes in the body prepare the body for a fight or flight response

Answer 39

increased heart rate increased blood pressure so more blood to working muscles increased glucose levels in the blood for energy

Question 40

what happens in stage 1 of the menstrual cycle and what's this stage called

Answer 40

Day 1 - Menstruation uterus lining break down and is released (bleeding)

Question 41

what happens in stage 2 of the menstrual cycle

Answer 41

Day 4 to 14 lining of the uterus builds up again, ready to receive a fertilised egg

Question 42

what happens in stage 3 of the menstrual cycle and what's this stage called

Answer 42

around day 14 - ovulation an egg develops and is released from an ovary

Question 43

what happens in stage 4 of the menstrual cycle and what's this stage called

Answer 43

day 14 to day 28 lining is maintained, if no fertilised egg has been implanted into uterus, the cycle repeats

Question 44

what does the hormone FSH do

Answer 44

causes an egg to mature in an ovary stimulates the ovaries to produce oestrogen

Question 45

what does the hormone oestrogen do

Answer 45

causes uterus lining to thicken and grow stimulates production of LH inhibits product of FSH so only one egg is released per cycle

Question 46

what does the hormone LH do

Answer 46

stimulates the release of an egg indirectly stimulates production of progesterone

Question 47

what does the hormone progesterone do

Answer 47

maintains the lining of the uterus, when progesterone levels falls, the uterus lining breaks down inhibits production of FSH and LH low progesterone levels trigger FSH to increase and cycle restarts

Question 48

which 2 hormones do hormonal contraceptives contain and why

Answer 48

oestrogen and progesterone oestrogen inhibits FSH production progesterone stimulates mucus production so sperm can't enter the cervix

Question 49

whats a contraceptive patch

Answer 49

sticker placed on upper arm which releases oestrogen and progesterone. must be replaced every week

Question 50

whats a contraceptive injection

Answer 50

injection of progesterone into the upper arm, last 2-3 months

Question 51

whats a contraceptive implant

Answer 51

device placed under skin of arm which releases progesterone needs to be replaced every 3 years

Question 52

whats a intrauterine device (IUD)

Answer 52

a plastic device that releases progesterone/ a copper coil which kills sperm cells when they enter the uterus need to be replaced every 3+ years

Question 53

initially what happens if a women can't conceive naturally and what happens if this doesn't work

Answer 53

they're give FSH and LH if this doesn't work, IVF can be used

Question 54

what does IVF stand for and what are the stages

Answer 54

IVF stands for in vitro fertilisation stage 1, the woman is given FSH and LH to promote growth stage 2, egg cells and sperm cells are gathered stage 3, the egg id fertilised by the sperm cell stage 4 - the embryo is kept in an incubator to allow it to grow stage 5, once the embryo has grown enough, it is injected into the woman's uterus

Question 55

what is ICSL

Answer 55

where sperm is injected into an egg cell using tiny needle

Question 56

what are auxins

Answer 56

plant hormones which control growth at the tips of the roots and shoots promotes growth at the shoots and inhibits growth at the roots respond to light (phototropism) and gravity (gravitropism/ geotropism)

Question 57

what are shoots in terms of phototropism and gravitropism)

Answer 57

positively phototropic negatively geotropic

Question 58

what are roots in terms of phototropism and geotropism

Answer 58

positively geotropic negatively phototropic

Question 59

what gibberellin

Answer 59

stimulates the plant stems to grow

Question 60

whats ethene

Answer 60

stimulates shedding of leaves and ripening of fruit

Question 61

how is selective herbicides used to control plant growth

Answer 61

auxins affect broad leaved plants which disrupts normal growth and kills them, this leaves narrow leaved cereals and crops untouched

Question 62

how is root powder used to control plant growth

Answer 62

use cutting (a part of a plant that has been cut off), which normally don't grow on their own but if you add root powder which contains auxins there produce roots and can grow rapidly

Question 63

how can you produce seedless fruits

Answer 63

normally plants don't grow without being pollinated. However if auxins and gibberellins are added to unpollinated fruit then the fruit grows and the seeds don't

Question 64

how can dormancy be controlled

Answer 64

lots of seeds won't grow under certain conditions (dormancy) seeds can be treated with gibberellins to alter dormancy, allowing plants to grow at times of the year they usually wouldn't, also helps to make sure that batch grows at the same time

Question 65

what is homeostasis

Answer 65

maintaining a stable internal environment, despite changing conditions

Question 66

what conditions need to be regulated through homeostasis for a cell to function properly

Answer 66

maintain: temp pH glucose levels good supply of water

Question 67

what's the automatic control system and how does it work

Answer 67

a control system detects a change in the optimal conditions, uses a signal and reverses the change

Question 68

what 3 components manage the automatic control systems how does this system work

Answer 68

receptors - detect the change co-ordination centres - interpret the change and what needs to be done effectors - carry out the change signal is transported by either nervous or endocrine system work through negative feedback

Question 69

whats thermoregulation

Answer 69

a control of internal body temp through negative feedback

Question 70

what happens when body is too cold

Answer 70

constrict blood vessels at the skin shivering raise skin hairs

Question 71

what happens when body is too hot

Answer 71

lower skin hairs dilate blood vessels near the skin sweating

Question 72

why do glucose levels need to be regulated

Answer 72

to ensure there is enough glucose to respire

Question 73

how does insulin work

Answer 73

the pancreas detects a change in glucose conc. in the blood insulin is released which stimulates muscles and the liver to absorb glucose from blood liver is a long term storage which converts glucose into glycogen

Question 74

how does glucagon work

Answer 74

when glucose conc. falls it's detected by the pancreas pancreas releases glucagon into blood hormone travels around body and binds mainly to cells in the liver stimulates liver cells to breakdown glycogen into glucose and release it into the blood, returning glucose levels to normal

Question 75

whats the problem with type 1 diabetes and how is it managed

Answer 75

pancreas doesn't release enough insulin can be managed by injecting insulin, monitoring diet and regular exercise

Question 76

whats the problem with type 2 diabetes

Answer 76

body tissues become resistant to insulin

Question 77

what do the kidneys do

Answer 77

regulate levels of waste products, ions and water in the bloodstream (filters the blood)

Question 78

how is urea made and how is urea reabsorbed

Answer 78

through deamination - where excess amino acids are converted into fats and carbohydrates for storage no urea is reabsorbed

Question 79

why and how are ions regulated in the blood

Answer 79

if levels of ions get too high or to low it can damage the cells, it's regulated through sweating however mainly through the kidneys. Depending on how much is already in the blood, ions are selectively reabsorbed

Question 80

how are water levels regulated in the blood

Answer 80

can be lost partly through sweating and breathing, however mainly through the kidneys. To much water can cause the cells to expand or shrink - potentially burst the hypothalamus detects water conc. in the blood and if there's to much water it sends a signal to the pituitary gland which releases ADH. This signals the kidneys to reabsorb less water so less urine is produced and vice versa.

Question 81

through what blood vessels does blood enter and leave the kidneys

Answer 81

enters through the renal arteries leaves through the renal veins

Question 82

how is urine transported from the kidneys to the bladder

Answer 82

through the ureters, waiting to be disposed through the urethra

Question 83

whats filtration in the kidneys

Answer 83

very small substances get absorbed into the bowman's capsule from the glomerulus like glucose, urea, water and amino acids

Question 84

whats the nephron and describe the pathway of products

Answer 84

nephrons are small structures in the kidneys which filter the blood. The blood enters the kidneys through the renal arteries into the glomerulus where small particles are absorbed into the bowman's capsule where blood goes through the proximal convoluted tube then the loop of Henle then the distal convoluted tube and if particles have not been reabsorbed they go into the collecting duct and come out as urine.