Biology 0610/43 May/June 2024: question paper and mark scheme
Cambridge IGCSE Biology (0610), Paper 4 Theory (Extended), May/June 2024. Read both free below, or download them. Done the paper? Get it marked by AI against this mark scheme.
Fig. 1.1 is a diagram of an animal cell.
A
B
C
D
Fig. 1.1
(a) Complete Table 1.1 by writing the name and function of each of the labelled parts of the cell shown in Fig. 1.1.
Table 1.1
label in Fig. 1.1 name function
A
B
C
D
[4]
(b) (i) Explain how water moves into and out of animal cells.
…… [3]
(ii) A sample of red blood cells was taken from a person. The red blood cells were put into three test‑tubes. Each test‑tube contained a different liquid:
• blood plasma
• pure water
• a very concentrated salt solution.
Fig. 1.2 shows the appearance of the red blood cells when examined using a microscope.
Identify the liquids the red blood cells were immersed in.
Write your answers in the spaces provided in Fig. 1.2.
Fig. 1.2
[2]
(iii) State the name of the molecule in red blood cells that combines with oxygen.
…… [1]
(iv) Fig. 1.3 shows a drawing of a white blood cell.
Fig. 1.3
Identify the type of white blood cell shown in Fig. 1.3.
…… [1]
[Total: 11]
Mark scheme
1(a) 4 one mark per correct row
label
in Fig. name function ecf if no correct functions given but all names
1.1 are correct award 1 mark
stores genetic information / contains
A nucleus
DNA / controls (activity of) the cell
where (metabolic / chemical) reactions
B cytoplasm
take place
cell
C controls what goes into and out of the cell
membrane
aerobic respiration / provide energy
using oxygen / produce ATP
D mitochondria
using oxygen / release energy using
oxygen
;;;;
1(b)(i) any three from: 3
by osmosis ;
from high(er) water potential to low(er) water potential / down a water
potential gradient ;
through a partially permeable membrane ;
ref. to, kinetic energy / random motion of molecules ;
1(b)(ii) in this order vertically: 2 three correct = 2 marks
(blood) plasma one or two correct = 1 mark
(a very concentrated) salt solution
(pure) water
;;
1(b)(iii) haemoglobin ; 1
1(b)(iv) phagocyte ; 1
Fig. 2.1 is a photograph of a spider plant, Chlorophytum comosum. Spider plants can reproduce by producing an identical plantlet, which grows away from the single parent plant.
parent plant
offspring plantlet
Fig. 2.1
(a) (i) Identify one feature in Fig. 2.1 that shows that spider plants are monocotyledons.
…… [1]
(ii) Describe the advantages and disadvantages of asexual reproduction in a population of spider plants in the wild.
…… [4]
(b) Fig. 2.2 shows pollen that has been released from the flowers of a hazel tree,
Corylus avellana. These flowers are wind‑pollinated.
pollen
Fig. 2.2
(i) Explain why a hazel tree has to produce very large amounts of pollen.
…… [1]
(ii) Describe how a stigma from a wind‑pollinated plant is adapted for pollination.
…… [1]
(c) The hazel tree uses cross‑pollination rather than self‑pollination.
Describe cross‑pollination.
…… [2]
(d) Outline the events that occur in the flower after pollination.
…… [4]
[Total: 13]
Mark scheme
2(a)(i) any one from: 1
strap-shaped / narrow / AW, leaves ;
parallel / not branched, veins ;
2(a)(ii) any four from: 4
advantages
1 fast ;
2 no need for, pollination / pollinators ;
3 no need for, pollen / gametes / fertilisation ; A only one parent plant / no mate, needed
4 offspring adapted to parent’s environment ; A no genetic variation is an advantage in a
stable environment
disadvantages
5 no / low, (genetic) variation ;
6 more susceptible to (named) environmental change ; e.g. climate change
7 more susceptible to a new disease OR disease spreads fast
through a population ;
8 offspring are, very close / in competition ;
9 AVP ; e.g. less energy needed
2(b)(i) increases the chance of reaching a, stigma / plant / AW ; 1 A more chance of, reproduction / pollination
A most will be, blown way / lost / AW
2(b)(ii) large / long / feathery / (hanging) outside the flower ; 1
2(c) the transfer of pollen grains from the anther to the stigma ; 2
on a different plant of the same species ;
2(d) any four from: 4
1 pollen tube growing from a pollen grain ;
2 pollen (tube / grain) releases enzymes ;
3 (pollen tube) grows down style / grows into ovary ;
4 pollen / male, nucleus travels down the pollen tube ;
5 pollen tube grows / pollen nucleus or male nucleus moves, through
the micropyle / (in)to the ovule ;
6 fertilisation occurs ;
7 pollen / male, nucleus fuses with female nucleus ;
8 zygote formed ;
9 AVP ; e.g. ref. to mitosis
(a) Proteins are biological molecules.
Explain how proteins are made.
…… [6]
(b) Fig. 3.1 is a diagram of enzyme 1 catalysing the breakdown of molecule A into two smaller molecules, B and C.
molecule A molecule C molecule B
enzyme 1
Fig. 3.1
Molecule D, shown in Fig. 3.2, is added to the mixture shown in Fig. 3.1.
This causes the rate of production of molecules B and C to decrease.
molecule A
molecule D
enzyme 1
Fig. 3.2
(i) Using the information in Fig. 3.1 and Fig. 3.2, suggest why the rate of production of molecules B and C decreases after molecule D is added.
…… [2]
(ii) Fig. 3.3 shows enzyme 1 after a change in its environmental conditions.
enzyme 1
Fig. 3.3
Suggest two changes that could cause the effect on enzyme 1 shown in Fig. 3.3.
1 ……
2 ……
[2]
[Total: 10]
Mark scheme
3(a) any six from: 6
messenger RNA (mRNA) is a copy of, a gene / DNA ;
mRNA is made in the nucleus ;
the gene (coding for the protein) / DNA, remains in the nucleus ;
mRNA moves to the, cytoplasm / ribosome ;
mRNA passes through ribosomes ;
the ribosome assembles amino acids into, polypeptide / protein ;
the (specific) sequence of amino acids is determined by the sequence of
bases in mRNA ;
AVP ; e.g. DNA unwinds
3(b)(i) any two from: 2
(molecule) D has a similar shape to (substrate) A ;
shape of (molecule) D is complementary to the active site ;
(molecule) D, binds to / fits, the active site ;
reduces / prevents, (substrate) A binding to enzyme ;
idea of (substrate) A cannot be broken down / less substrate A is broken
down ;
3(b)(ii) increased temperature ; 2
(increased / decreased / extreme) pH ;
Characteristics of plants are controlled by genes. Alleles are alternative forms of a gene.
(a) Explain how new alleles are formed.
…… [2]
(b) The number of hours of daylight affects when plants produce flowers. This ensures that flowers are produced at an appropriate time of year for each species.
This response to the number of hours of daylight is controlled by genes.
(i) Wheat is a crop plant. A farmer wants to produce a type of wheat that flowers when there are fewer hours of daylight.
Describe how the farmer could selectively breed this type of wheat.
…… [3]
(ii) Wheat is grown from seeds.
State two conditions needed for the germination of seeds.
1 ……
2 ……
[2]
(iii) Different types of wheat have also evolved through natural selection.
Explain how natural selection differs from artificial selection.
…… [3]
(c) Scientists can selectively breed for increased pest resistance in wheat.
Explain the benefits of growing wheat with increased pest resistance.
…… [2]
[Total: 12]
Mark scheme
4(a) any two from: 2
through mutation ;
(mutation is ) a change in the base sequence of DNA ;
(mutation is) caused by, ionising radiation / chemicals ;
4(b)(i) any three from: 3
selection of individual plants which, flower in fewer hours of daylight
/ show the desirable feature ;
crossing these individuals to produce the next generation ;
selection of offspring that show the desirable feature ;
repeat for (many) generations ;
AVP ; e.g. place bag over the plant to prevent
unwanted pollination / pollinate with a
paintbrush / relevant description of method
4(b)(ii) any two from: 2
water ;
oxygen ;
a suitable temperature ;
4(b)(iii) any three from: 3
in natural selection
selection pressure / AW, comes from the environment ;
better adapted individuals (survive and) reproduce ;
(always) produces characteristics suitable for the (new) environment ;
slower ;
affects many characteristics ;
4(c) any two from: 2
less pesticides used ;
less contamination of food with pesticides ;
less pollution / described ;
less damage to / higher yield of / higher quality of, crop ;
less risk to pollinators / non target species ;
improve health of farm workers ;
less spread of plant disease ;
increases biodiversity ;
Phytoplankton are microorganisms that photosynthesise.
(a) State the chemical equation for photosynthesis.
…… [2]
(b) A scientist made notes about a marine food web.
Fig. 5.1 shows the notes she made.
• In the sea, phytoplankton photosynthesise.
• Phytoplankton are eaten by small organisms in the sea, called zooplankton.
• Herring fish and cod fish eat phytoplankton. Herring fish also eat zooplankton.
• Cod fish eat other fish such as herring.
Fig. 5.1
(i) Using the information in Fig. 5.1, complete the food web in Fig. 5.2.
orca
leopard seal
Adélie crabeater penguin seal
krill
Fig. 5.2
[2]
(ii) State the principal source of energy for this food web.
…… [1]
(iii) Table 5.1 describes features of the food web in Fig. 5.2.
Complete Table 5.1, using the information in Fig. 5.2.
Table 5.1
feature of the food web maximum number in the food web in Fig. 5.2
trophic levels
primary consumers
tertiary consumers
[3]
(iv) Fig. 5.3 is a photograph of an orca.
Fig. 5.3
Using the information in Fig. 5.2, predict and explain the most likely effect of a decrease in the orca population on the population size of:
krill ……
leopard seals. ……
[2]
(c) Krill and seals can be harvested to produce omega‑3 fatty acids.
Many people take omega‑3 fatty acids as a dietary supplement as they are thought to have health benefits in humans.
(i) List the chemical elements found in all fats.
…… [1]
(ii) Using the information in Fig. 5.2, explain why it is more energy efficient to use krill as a source of omega‑3 fatty acids rather than seals.
…… [4]
(d) Describe how fats ingested by humans are digested and absorbed.
…… [4]
[Total: 19]
Mark scheme
5(a) 6CO2 + 6H2O → C6H12O6 + 6O2 ;; 2 MP1 for correct reactants
MP2 for correct products
5(b)(i) phytoplankton and zooplankton in the correct positions ; 2
herring (fish) and cod (fish) in the correct positions ;
5(b)(ii) the Sun / sunlight ; 1
5(b)(iii) 3
maximum number in
feature of the food web
the food web in Fig. 5.2
trophic levels 6;
primary consumers 5;
tertiary consumers 3;
5(b)(iv) krill: 2
decrease (in population size) as more predation (by crabeater
seal / Adélie penguin) ;
leopard seal:
increase (in population size) as less predation (by orca) ;
5(c)(i) carbon, hydrogen and oxygen ; 1
5(c)(ii) 1 energy is lost at each trophic level / AW ; 4
2 & 3 (energy lost through)
metabolism / excretion / movement / faeces / indigestible parts
/ active transport / thermoregulation ;;
4 krill is at a lower trophic level than seals ; ora A krill is on the 2nd trophic level and seals are
on 3rd / 4th / 5th trophic level
A in terms of primary / secondary / tertiary
/ quaternary consumers
5(d) any four from: 4
physical / mechanical digestion ;
emulsified by bile (in the small intestine) ;
increase the surface area of fats (for enzymes) ;
(fats digested by) lipase ;
(lipase) secreted / produced, by pancreas ;
(lipase) breaks fat down into glycerol and fatty acids ;
absorbed by, lacteals / (micro)villi ;
(absorbed) in small intestine ;
Fig. 6.1 shows a boreal toad, Anaxyrus boreas. This toad is listed as an endangered species.
Fig. 6.1
(a) State the genus of the boreal toad.
…… [1]
(b) One reason for the boreal toad’s recent decrease in population is a disease caused by chytrid fungus.
State two reasons other than disease that could cause the boreal toad to become endangered.
1 ……
2 ……
[2]
(c) Scientists investigated whether increasing the number of beneficial bacteria that live on the toads’ skin could provide protection against the fungus. The scientists took 42 toads and placed 21 in group 1 and 21 in group 2.
• Group 1 – the toads’ skin was treated with beneficial bacteria.
• Group 2 – the toads’ skin was not treated with beneficial bacteria.
The scientists measured the number of toads that became infected with the fungus.
Table 6.1 shows the results.
Table 6.1
time since treatment with number of toads with fungal infection beneficial bacteria / days group 1 group 2
0 0 0
20 2 2
40 3 4
60 9 17
80 13 19
100 13 21
(i) Calculate the percentage of the 21 toads that have the fungal infection after 100 days in group 1 in Table 6.1.
Give your answer to two significant figures.
Space for working.
……%
[3]
(ii) Using the information in Table 6.1, describe the effect of treating the toads with beneficial bacteria.
…… [2]
(d) There are conservation programmes to reintroduce boreal toads into their natural habitat.
(i) Describe why conservation programmes are set up for animals like the boreal toad.
…… [3]
(ii) Conservation programmes for other endangered animals, such as birds, use artificial insemination as part of a captive breeding programme.
Describe how artificial insemination is carried out as part of a captive breeding programme.
…… [4]
[Total: 15]
Mark scheme
6(a) Anaxyrus ; 1
6(b) any two from: 2
climate change / global warming ;
habitat destruction / deforestation ;
hunting ;
pollution ;
introduced species ;
overharvesting ;
AVP ; e.g. disruption of food chain / increase in
predation / decrease in food supply / increased
competition for resources
6(c)(i) 62 (%) ;;; 3 MP1 correct selection of data i.e. 13
MP2 correct calculation to any number of
significant figures
MP3 rounding to two significant figures
ecf from previous step if evidenced in working
6(c)(ii) any two from: 2
bacterial treatment reduces the number of toads with fungal infection ;
there is no effect of treatment in 0 to 20 / (first) 40 days ;
bacteria treatment reduces fungal infections from, 40 to 100
/ 60 to 100 days ;
suitable comparative data quote ;
6(d)(i) any three from: 3
maintaining / increasing, biodiversity ;
reducing extinction / increase population size / repopulate ;
maintaining food, webs / chains ;
maintaining source of future, food / drugs / genes ;
protecting vulnerable, ecosystem / habitat ;
ref. to effects on nutrient cycles ;
AVP ; e.g. idea of protecting keystone species
/ research / monitoring / education / moral
responsibility / aesthetic reasons / ecotourism
6(d)(ii) any four from: 4
collect, sperm / gamete / semen (from male) ;
males can be chosen from different breeding programmes ;
to maximise genetic variation ;
sperm, screened / quality checked / AW ;
sperm / semen, frozen ;
(female) given drugs to induce ovulation ;
sperm / semen, placed in, vagina / uterus / oviduct ; A cloaca
sperm / semen, inserted at appropriate time for ovulation ;
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Biology 0610/43 for May/June 2024 is out of 80 marks, with 1 hour 15 minutes to answer it, across 6 questions.
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