homeostasis

Question 1

describe how woman’s nervous system coordinates reflex action of moving hand away from hot object

Answer 1

• receptor detects stimulus
• electrical impulses pass along sensory neurone
• sensory to relay to motor
• synapses between neurones where chemical crosses gap
• synapses in spinal cord
• effector is muscle which contracts

Question 2

explain why a person with type 2 diabetes has a higher blood insulin conc than normal

Answer 2

• cells absorb less glucose
• so glucose conc in blood remains high
• causes pancreas to release more insulin

Question 3

explain why protein isn’t found in urine of healthy person

Answer 3

• molecules too large
• so can’t pass through filtration membrane

Question 4

explain why glucose isn’t found in urine of healthy person

Answer 4

• all of glucose is reabsorbed

Question 5

explain how impulses are transmitted at the synapse

Answer 5

• impulse stimulates release of neurotransmitter
• neurotransmitter diffuses across synapse
• binds to receptors to stimulate an electrical impulse in the next neurone

Question 6

explain why brain injuries are hard to treat

Answer 6

• difficult to access
• risks damage to the brain

Question 7

describe and explain how type 2 diabetes occurs in the body

Answer 7

• blood glucose levels are high
• as cells are resistant to insulin
• liver / muscle cells don’t absorb glucose

Question 8

explain how exercise can be used to treat type 2 diabetes

Answer 8

• decreases blood glucose
• as glucose used in respiration

Question 9

why does a liver not functioning properly lead to too many amino acids in plasma?

Answer 9

• deamination can’t occur
• so amino acids can’t be removed and filtered by the kidneys

Question 10

how to measure curved seedling?

Answer 10

• straighten seedling and measure with a ruler
• flexible tape measure
• use a piece of thread and measure length of thread with ruler

Question 11

explain what happened to the growth of side in dark v light, using lamp

Answer 11

• side nearest lamp receives more light
• therefore unequal distribution of auxin
• causes more growth on side away from lamp

Question 12

why did the students surround the seedlings with damp blotting paper?

Answer 12

to prevent water affecting the direction of root growth

Question 13

gravity experiment how does one turning continuously act as a control?

Answer 13

• gravity acts evenly on all sides

Question 14

describe cell growth continuous spin

Answer 14

• even distribution of hormone
• so equal growth

Question 15

describe cell growth gravity effect

Answer 15

• unequal distribution of hormone
• top grows faster / bottom grows slower

Question 16

effectors and response

Answer 16

• muscles contract
• glands secrete hormones

Question 17

oestrogen

Answer 17

• cause uterus lining to thicken
• inhibit FSH
• stimulates LH production

Question 18

progesterone

Answer 18

• inhibits both FSH and LH
• maintains thick uterus lining

Question 19

where does auxin go once prudced?

Answer 19

it diffuses along the roots / shoots

Question 20

wording of spine

Answer 20

spinal cord

Question 21

explain how the person’s eye could adjust to form a clear image of a nearer object

Answer 21

• ciliary muscles contract
• so have a smaller diameter
• suspensory ligaments loosen
• so lens thickens
• light refracted more
• so image focused on retina

Question 22

explain why a long-sighted person has difficulty seeing near objects clearly

Answer 22

• eyeball too short
• so light focuses behind retina

Question 23

describe how spectacle lenses can correct long-sightedness

Answer 23

• convex lens
• light refracted more
• light rays focused on retina

Question 24

homeostasis definition

Answer 24

the regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes

Question 25

too hot

Answer 25

- sweating: evaporation cools body - heart rate increase: moves blood towards surface

Question 26

explain how the nervous system controls the change in pupil size from bright to dim

Answer 26

- light receptors in retina detect changes in light intensity - optic nerve transmits electrical impulses to the brain - coordination centre in the brain processes impulse - motor neurones send impulses to muscles in iris which carry out response - + response but you already know that

Question 27

name a plant hormone used for this encouraging growth in cuttings and explain how it promotes root growth

Answer 27

auxin, stimulates root development helping cuttings develop into full plants