BIOLOGICAL MOLECULES &
MOVEMENT INTO AND OUT OF CELLS
2025
BIOLOGY
Grade 10
Name and Surname
Centre Number
ZA331
Date
[ 65 minutes ]
INSTRUCTIONS:
-
Read your questions carefully.
Answer all questions.
Circle only one answer in pencil for multiple choice questions. If you make a mistake
clearly erase the pencil.
Write your answer to each question in the space provided.
You should show all your work on the question paper.
INFORMATION
-
The total mark for this paper is 65 marks.
The number of marks for each question or part question is shown in brackets [ ].
This document consists of 21 printed pages.
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RUIMSIG ACADEMY is a registered Cambridge International School
Centre Number ZA331
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THEORY QUESTIONS
1
Plants can make glucose and proteins.
Using the words from the list, complete the table to show all of the chemical elements that are found
in glucose and all proteins.
Each word may be used once, more than once or not at all.
carbon
hydrogen
oxygen
nitrogen
magnesium
glucose
all proteins
[2]
[Total: 2]
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2
Dialysis tubing is an artificial membrane, which is similar to the lining of the intestine.
A student investigated the diffusion of glucose through dialysis tubing by using the apparatus shown
in the diagram.
The student took samples of the water outside the dialysis tubing at 5 minute intervals and tested
the samples with Benedict’s solution. The results are shown in the table.
time / minutes
results of the Benedict’s tests on the water outside
the dialysis tubing
0
blue
5
green
10
yellow
15
red
Describe and explain the results shown in the table.
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[3]
[Total: 3]
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3
This question is about biological molecules.
Choose words or phrases from the list to complete the sentences.
Each word or phrase may be used once, more than once, or not at all.
calcium
carbon
cellulose
chloroplasts
glycogen
oxygen
carbon dioxide
carbohydrate
fat
glycerol
iron
methane
nitrogen
protein
starch
Fats are composed of the elements .............................................. , hydrogen and
.............................................. only. All proteins contain these three elements and the
element ............................................. .
Glucose is a type of ............................................... .
Animals store excess glucose as .............................................. in the liver.
Plants store excess glucose as .............................................. . Plants also convert glucose
to .............................................. which is used to make cell walls.
[7]
4
[Total: 7]
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Starch is broken down into reducing sugars in the alimentary canal. The digested products are
absorbed into the blood.
Some students investigated the action of enzymes on the digestion of starch.
Describe how you would carry out a test for starch.
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[2]
[Total: 2]
5
In an investigation, students kept unripe bananas at room temperature for eight days.
They studied some of the changes during ripening.
Each day the students took one banana and:
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observed the colour of the banana skin;
removed a sample of the flesh tissue and estimated the reducing sugar content.
The table below shows the students' results.
time / days
(a)
(i)
change during ripening
skin colour
reducing sugar content /
%
1
green
5
2
green and yellow
12
3
mostly yellow
18
4
all yellow
25
5
all yellow
30
6
yellow, some brown
29
7
yellow and brown
30
8
mostly brown
30
Suggest on which day the bananas became ripe. State one reason for your answer.
day..........................................................................................................................
reason....................................................................................................................
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[2]
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(ii) The reducing content increased as the banana ripenend.
Calculate how many times greater was the sugar content on day 5 compared with day
1.
Show your working.
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[2]
(iii) Suggest the source of the reducing sugar.
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[1]
[Total: 5]
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Describe how you would safely carry out a test for reducing sugars.
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[3]
[Total: 3]
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