bio paper 2

Question 1

how do you reduce the chance of developing type 2 diabetes

Answer 1

more excercise
less sugar/carbohydrates

Question 1

Explain the effect a high concentration of insulin has on blood glucose concentration

Answer 1

lowered bc glucose converted to glycogen

Question 2

three harmful substances that can cause water pollution

Answer 2

fertiliser
sewage
toxic chemicals
herb/fungicide

Question 3

describe the effect of fertiliser leaking into rivers

Answer 3

algae multiply and block light so plants can’t photosynthesise
lack of oxygen 4 respiration – fish die

Question 4

effect of carbon monoxide on organisms

Answer 4

combines w/ haemoglobin
less o2 carried by blood

Question 5

effect of particulates/soot on organisms

Answer 5

damage to lungs, bronchitis, ashtma
cover leaves, less photosynthesis, less glucose

Question 6

effect of acidic gases- so2,nox

Answer 6

damage to leaves, less photosynthesis
damage to roots/alters ions in soil- (eg phosphates) so less protein made
damage to lungs, bronchitis, asthma

Question 7

effect of GHGs on organisms

Answer 7

climate change->
flood, fires, droughts, ice melt,sea
level, extreme weather
o loss of habitat / food
o migration

Question 8

how can oil affect organisms

Answer 8

damages birds’ feathers
can’t fly and escape predators/get food

Question 9

effect of acid rain / acid on organisms

Answer 9

lowers pH of water
damages fish gills
bleaches coral

Question 10

effect of toxic substances on animals

Answer 10

damages / harms cells or bioaccumulation
o interferes with metabolism – e.g. respiration / protein
synthesis

Question 11

uses of water in plants

Answer 11

photosynthesis
support
solvent for translocation

Question 12

It is more energy-efficient to rear cows indoors than to rear cows outdoors

Answer 12

less energy lost as
-heat
-movement

Question 13

Suggest possible disadvantages of rearing cows indoors

Answer 13

• increased spread of disease
  or
  increased use of drugs
  / antibiotics (to
  reduce disease)
• more antibiotics in meat / milk
• (extra) cost of heating /
  lighting / food / drugs
• aggressive behaviour
  (causing harm)
  or
  ‘emotional’ stress reduces
  productivity

Question 14

what is a mutation?

Answer 14

a change in DNA

Question 15

why did the scientist dilute the pond water?

Answer 15

to make the algae cells easier to count

Question 16

2 Explain why the decrease in body temperature is an advantage to the echidna
during hibernation.

Answer 16

lower temperature gradient
(between echidna and air) (1)
(so) loses less energy (1)
more energy available for vital life processes

Question 17

Explain why the echidna has a higher body temperature when it is active.

Answer 17

activity / movement requires
energy from respiration
(and) respiration / metabolism
releases heat (which increases
body temperature)
OR
respiration / metabolism
releases heat (which increases
body temperature) (1)
(which) increases the rate of
chemical reactions
or
increases enzyme activity (1)

Question 18

Explain how the dilation of blood vessels in the skin can help to decrease
body temperature

Answer 18

more blood flow to skin-> more heat is lost from blood
cools blood ->cools the
body

Question 19

Suggest why the athlete was advised to take salt tablets each day.

Answer 19

replace salt lost in sweat

Question 20

what is represented by a pentagon in drawings of DNA?

Answer 20

sugar

Question 21

what is A complementary?

Answer 21

T

Question 22

ideas for constant variables

Answer 22

volume
mass
SA
temperature
pH
species

Question 23

when a person drinks ice cold water, their brain’s temperature decreases- why?

Answer 23

blood cooled at stomach and flows to brain

Question 24

How does the thermoregulatory centre send information to sweat glands in the skin?

Answer 24

via neurones

Question 25

During exercise, the skin appears red.
What causes the skin to appear red?

Answer 25

dilation of blood vessels in the
skin

Question 26

• how microorganisms in the layers of soil help to recycle chemicals in the
  dead plants
• how the chemicals are used again by living plants.

Answer 26

digestion
enzymes
respiration
produce co2
release ions

in plants
co2 taken in by leaves by diffusion via stomata for photosynthesis which makes glucose/sugar/starch/cellulose or making
named ions taken in by roots by AT
nitrate ions to make AAs/proteins
phosphate for DNA

Question 27

is shade from a building abiotic or biotic

Answer 27

abiotic

Question 28

How should the student decide where to place the quadrat?
Give the reason for your answer.

Answer 28

grid+coords
to achieve randomness

Question 29

Using the mean from this investigation to calculate the number of daisy plants on the
lawn may not be accurate.
Give two reasons why

Answer 29

too few quadrats
or quadrat too small
sample may not be
representative of the lawn

Question 30

What is meant by the term ‘reflex action’?

Answer 30

response / reaction
automatic or no thinking or not
conscious or involuntary
ignore ref to brain

Question 31

A woman’s hand accidentally touches a hot object.
The woman moves her hand away rapidly.
Describe how the woman’s nervous system coordinates the reflex action.

Answer 31

receptor in skin of hand detects stimulus (temp change)
electrical impulses pass along neurones
impulses pass from sensory to relay to motor neurones
synapse between neurones where chemical crosses gap
synpases in spinal cord/CNs
effector is a muscle to pull the hand away

Question 32

endocrine vs nervous

Answer 32

encocrine:
slower, chemical, longer-lasting

Question 33

Describe how hormones control the menstrual cycle

Answer 33

FSH release from pituitary
stimulates maturation of egg
oestrogen from ovary inhibits FSH production, stimulates LH production

LH from pituitary
stimulates ovulation

progesterone release from
ovary inhibits FSH and LH
production
oestrogen and progesterone
maintain uterus lining

Question 34

The biomass of mackerel is much less than the combined biomass of krill and squid.
One reason for this is that the mackerel cannot digest all parts of the krill and squid.
Give two other reasons.

Answer 34

non eaten parts of squid/krill
energy used in respiration
excretion by mackerel

Question 35

Give evidence from Figure 17 to support the scientists’ suggestion.

Answer 35

parents of a given beak depth
produce offspring with several
beak depths