BIOLOGY 2022 Flashcards
Plan an investigation using chemical X to compare the number of earthworms per m2
in areas A and B.
- same concentration of chemical / X applied to the soil
- same volume / amount of chemical / X applied to the soil
- same size of area sampled – eg 1 m2 or 0.25 m2
- use of a quadrat
- same time between application and collecting worms
- same time allowed for collecting worms after application
- each sample area selected randomly
- method of achieving randomness – eg random coordinates
- (collect and) count worms in each of areas A and B
- at least 5 repeats in each of areas A and B
- calculate mean (per unit area) or total for each of areas A and B
- compare means / totals for areas A and
biotic factors
biotic
any two from:
* food
* predators / consumers /
carnivores
* disease / pathogens / bacteria
/ fungi
Name three harmful substances that could cause water pollution.
Do not refer to plastic or to litter in your answer
any three from:
* fertiliser
* sewage
* toxic chemicals
* herbicide
* fungicide
Describe how substances that pollute air and water could be harmful to humans and
other living organisms
air pollution:
(carbon dioxide or methane or greenhouse gases)
* global warming / climate change / traps heat
o floods / fire / drought or ice caps melt or rise in sea
level or extreme weather
o loss of habitat / food
o migration
(acidic gas / named – eg SO2 / NOx)
* damage to leaves so less photosynthesis
* damage to roots or alters ions in soil (/ e.g. phosphates / iron)
o (so) less protein manufacture
* damage to lungs
o breathing difficulties / bronchitis / asthma
(carbon monoxide)
* combines with haemoglobin
o less oxygen carried (by haemoglobin / blood)
(particulates / ‘soot’)
* cover leaves or block light
o less photosynthesis so less glucose made
* damage to lungs
o breathing difficulties / bronchitis / asthma
water pollution:
(sewage)
* bacteria multiply
o use oxygen in respiration
o water animals cannot respire
o pathogens in water
(fertiliser)
* algae multiply
o (algae) block light so plants cannot photosynthesise
o lack of oxygen for respiration – fish die
(toxic substances)
* damages / harms cells or bioaccumulation
o interferes with metabolism – e.g. respiration / protein
synthesis
(plastics)
* entrap animals or causing internal damage if swallowed
(particles)
* block light
o plants / algae cannot photosynthesise so less glucose made
(oil)
* damages birds’ feathers
o cannot fly so cannot find food or escape predators
(acid rain / acids)
* lowers pH of water
o damages fish gills
o bleaches cora
Give one piece of evidence from Figure 4 which shows that MSUD is a
recessive condition.
parents without MSUD have a
child with MSUD
Explain why the blood of a person with MSUD will have a high concentration of
toxic substance P
(no enzyme 2 made so) cannot
break down the toxic substance
the toxic substance is still made
(from the amino acids)
toxic substance diffuses / moves
(from cells) into the blood
Explain why the urine of a person with MSUD will have a high concentration of
toxic substance P
the toxic substance passes
through filter in kidney/not taken back
into the blood
or
P passes through filter in kidney
(some / all) not reabsorbed
Explain why a person with MSUD must have a low-protein diet
proteins contain amino acids
or
proteins are made of amino
acids
must keep (certain) amino acids
in low amount
(so) toxic substance or P does
not build up in the body and
cause damage to cells / tissues /
organ
It is more energy-efficient to rear cows indoors than to rear cows outdoors.
Give two reasons why.
less energy lost as heat
less energy lost in movement
Suggest two possible disadvantages of rearing cows indoors
any two from:
* 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
Suggest why the scientist diluted the pond water before placing it on the special slide.
to make it easier to count
A student repeated the scientist’s method.
The student used a thin coverslip over the diluted pond water instead of the
thick coverslip.
The liquid pulled the thin coverslip downwards slightly.
Explain how the use of the thin coverslip would affect the results for the cell count.
smaller volume
so fewer cells or lower cell
count
Explain why the decrease in body temperature is an advantage to the echidna
during hibernation.
loses less energy (from its body)
(so) body energy store lasts
longer
OR
lower temperature gradient
(between echidna and air) (1)
(so) loses less energy (1)
OR
less energy transferred
maintaining (higher) body
temperature (1)
(so) more energy available for
processes vital for life (1
‘Light causes the breakdown of auxin.’
Give the evidence from Figure 14 that shows that auxin is not broken down by light
all four (blocks) have
(approximately) the same mass
of auxin
