ProcessesIB MYP Biology: Topic test

20 questions, 54 marks

IB MYP Biology

Processes topic test

Total 54 marks

Name

Class

Date

1
A farmer in Nigeria grows cassava. The leaves make glucose by photosynthesis, and much of this glucose is changed into starch, which is stored in the swollen roots that the family eats.
(a)
Which substances are the reactants in photosynthesis?
[1 mark]
ACarbon dioxide and water
BGlucose and oxygen
COxygen and water
DCarbon dioxide and glucose
(b)
In which part of a cassava leaf cell does photosynthesis take place?
[1 mark]
AMitochondria
BNucleus
CChloroplasts
DRibosomes
(c)
State two uses of the glucose made in the leaves, other than being stored as starch.
[2 marks]
Total for question 1: 4 marks
2
In Georgia, winemakers seal grape juice and yeast in large clay jars. Within a few days bubbles of gas rise through the liquid, and over several weeks the mixture becomes alcoholic.
(a)
Which substances does yeast make when it respires anaerobically?
[1 mark]
ALactic acid only
BCarbon dioxide and water
COxygen and ethanol
DEthanol and carbon dioxide
(b)
Compared with aerobic respiration, how much energy does anaerobic respiration release from one molecule of glucose?
[1 mark]
AMore
BLess
CThe same
DNone at all
(c)
Explain why anaerobic respiration releases less energy per molecule of glucose than aerobic respiration.
[2 marks]
Total for question 2: 4 marks
3
A grower in the Netherlands raises cucumbers in a greenhouse kept at 25 °C with constant lighting. She increases the carbon dioxide concentration of the air in steps and measures the rate of photosynthesis in arbitrary units. At 0.04% the rate is 8 units. At 0.08% it is 15 units, at 0.12% it is 20 units, at 0.16% it is 22 units and at 0.20% it is 22 units.
(a)
Describe the trend shown by these results.
[3 marks]
(b)
Explain why the rate does not increase above 0.16%, and use your answer to advise the grower.
[4 marks]
Total for question 3: 7 marks
4
On a space station, astronauts breathe in oxygen and breathe out carbon dioxide. Engineers are testing a chamber of algae lit by lamps, to see whether it could supply the astronauts with oxygen and remove their carbon dioxide. The algae also respire. Carrying tanks of compressed oxygen from Earth is the usual alternative.
(a)
Explain how the algae in the chamber could balance the gas exchange of the astronauts.
[6 marks]
(b)
Discuss whether the space station should rely on the algae chamber or on tanks of compressed oxygen.
[6 marks]
Total for question 4: 12 marks
5
A Siberian husky pulls a sledge across the snow for many hours. The cells in its muscles release energy by aerobic respiration, and some of this energy keeps its body warm.
(a)
Where in the husky's muscle cells does aerobic respiration take place?
[1 mark]
AChloroplasts
BMitochondria
CNucleus
DRibosomes
(b)
Which equation shows aerobic respiration?
[1 mark]
A $\mathrm{6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2}$
B $\mathrm{C_6H_{12}O_6 \rightarrow 2C_2H_5OH + 2CO_2}$
C $\mathrm{C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O}$
D $\mathrm{C_6H_{12}O_6 \rightarrow 2C_3H_6O_3}$
(c)
State two uses of the energy released in the husky's cells.
[2 marks]
Total for question 5: 4 marks
6
A student bubbles air from the atmosphere through limewater in one tube, and air that she has breathed out through limewater in a second tube. The limewater in the second tube turns cloudy much more quickly.
(a)
Which gas turns limewater cloudy?
[1 mark]
AOxygen
BNitrogen
CHydrogen
DCarbon dioxide
(b)
Why does the air that she breathed out contain more carbon dioxide than air from the atmosphere?
[1 mark]
ACells in her body release carbon dioxide by respiration.
BHer lungs make carbon dioxide by photosynthesis.
CNitrogen in the air is changed into carbon dioxide in her lungs.
DAir from the atmosphere contains no carbon dioxide.
(c)
State two variables that the student should keep the same so that the comparison is fair.
[2 marks]
Total for question 6: 4 marks
7
A student wants to show that a plant needs light to make starch. She covers part of one leaf of a geranium plant with black card, leaving the rest of the leaf uncovered, and leaves the plant in bright light for two days. She then removes the leaf and tests it for starch.
(a)
Describe how the student should test the leaf for starch.
[3 marks]
(b)
State a hypothesis for this investigation, with a scientific reason, and describe the results that would support it.
[4 marks]
Total for question 7: 7 marks
8
Phytoplankton are microscopic algae that photosynthesise in the oceans. In parts of the Southern Ocean their growth is limited by a lack of iron, which they need to make chlorophyll. Some scientists propose adding iron to the sea to increase phytoplankton growth and so remove carbon dioxide from the atmosphere. Phytoplankton also respire, and when they die they are decomposed by bacteria.
(a)
Explain how adding iron could increase the rate of photosynthesis, and why it might not reduce atmospheric carbon dioxide as much as hoped.
[6 marks]
(b)
Discuss whether adding iron to the ocean should go ahead.
[6 marks]
Total for question 8: 12 marks

End of questions

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).