CIE iGCSE Biology Paper 4 Prediction - 2025
CIE iGCSE Biology Paper 4 Prediction – 2025
Preparing for your IGCSE exam can be daunting, but with the right approach, you can achieve your goals with CIE iGCSE Biology Paper 4 Prediction
Ace your iGCSE exam! Find exam-style questions, detailed notes, and helpful resources to boost your understanding
iGCSE Practice Questions, Past Papers , Flashcards and notes available for iGCSE Students at IITian Academy.
Question 1
(a) Fig. 9.1 shows a green plant.
Plants need to move substances around between their leaves, stems and roots. One of the processes they use is translocation.
Describe the process of translocation.
(b) Fig. 9.2 shows the whole plant and sections through its root, stem and a leaf.
Fig. 9.2
On Fig. 9.2 use label lines and the letter X to identify one region of xylem in each section (root, stem and leaf).
Answer/Explanation
Ans:
(a) movement of sugars / named sugar/ amino acids ;
in phloem ;
from region of production/ leaves / source ;
to region of utilisation/ storage/ growth ;
energy required/AW ;
(b) correctly labelled:
xylem in leaf:;
xyelm in stem;
xylem in root;
Question 2
Fig. 5.1 shows the reproductive system of a man.
Fig. 5.1
(a) The functions of some of the parts of the reproductive system of a man are given in Table 5.1.
Complete Table 5.1 using information from Fig. 5.1. One row has been done for you:
Table 5.1
(b) (i) Some men have an operation called a vasectomy. This involves cutting the sperm ducts.
Place an X on Fig. 5.1 to show where the sperm duct would be cut.
(ii) State why this operation is carried out.
Answer/Explanation
Ans:
(a) 
(b) (i) centre of X anywhere on the sperm duct ;
(ii) to prevent sperm passing down the sperm duct ;
Question 3
Fig. 1.1 shows a woodlouse.
The woodlouse is a crustacean, one of the four groups of arthropod.
It is a herbivore that lives on land and eats decaying plant materials.
It breathes with gills that must be kept moist.
(a) Name two other groups of arthropod.
For each group state one feature found only in animals of that group.
(b) Some students were sent to find woodlice for an investigation.
Suggest and explain two reasons why populations of woodlice are usually found under
stones, decaying wood and leaves.
Answer/Explanation
Ans:
Question 4
(a) Fig. 3.1 shows a piece of apparatus used to measure reaction time. As soon as the bulb lights up, the student being tested presses the switch. The reaction time, in seconds, is then displayed on the timer.
Ten students each have one attempt on the timer.
The results of the investigation are shown in Fig. 3.2.
The average reaction time for the boys is 0.18 s.
Calculate the average reaction time for the girls. Show your working.
average reaction time for the girls ………………………………………………. s [2]
Answer/Explanation
Ans: 0.16;;
but (0.18 + 0.15 + 0.15 + 0.16 + 0.16) / 5;
(b) Fig. 3.3 shows the pathway for a simple reflex action.
(i) Complete the diagram by writing the correct words in the boxes.
Answer/Explanation
Ans: receptor / sensor; effector;
(ii) Blinking is a reflex action. Fig. 3.4 shows what is happening as an eye blinks and then opens again.
Suggest one reason why this reflex action is important to the body.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………[1]
Answer/Explanation
Ans: protection of eye surface / cornea (from dust / injury / AVP);
protection of retina from bright light;
maintaining eye surface moist with tears AW;
(c) Heroin is a powerful drug.
(i) Describe what is meant by the term drug.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………[2]
Answer/Explanation
Ans: any substance taken into the body; that modifies chemical reactions in the body / alters the metabolism;
(ii) Suggest how heroin could affect reaction time.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………[1]
Answer/Explanation
Ans: (heroin is a depressant so could)
slow down the transmission of impulses / AW;
or increase reaction time;
(iii) There are many problems caused by people using heroin.
Describe three examples of these problems.
1 ……………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
2 ……………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
3 ……………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………[3]
Answer/Explanation
Ans:
addiction, withdrawal symptoms, risk of overdosing, risk of
death,
infection from shared needles, damage to veins,
risk of HIV, risk of hepatitis C,
criminal behaviour, theft, imprisonment,
loss of inhibitions, aggression, violence, more prone to
accidents, poor judgement of behaviour, euphoria, mental
health problems,
social problems, family breakdown, loss of job, loss of home,
poor ability to work,
emotional problems / AW ( e.g. lack of self-esteem),
physical health problems, heart attacks, liver damage, brain or
neurone damage, respiratory failure, strokes,
d) An antibiotic is an example of a drug that can be used as a medicine.
Describe how antibiotics are useful to the human body.
…………………………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………………..[1]
[Total: 12]
Answer/Explanation
Ans: destroy / kill / inhibit bacteria;
Question 5
(a) Explain the terms allele and gene.
(b) PTC is a bitter tasting chemical that some humans can taste while others cannot. This
is controlled by a single gene with a pair of alleles.
(i) The allele for tasting PTC is dominant to the allele for not tasting PTC.
State evidence shown in Fig. 7.1 that supports this fact.
(ii) Use the symbols T for the dominant allele and t for the recessive allele to state the
genotypes for individuals 2 and 5.
(iii) What are the two possible genotypes for individual 3?
Answer/Explanation
Ans:
Question 6
Bacteria are used in many biotechnological processes.
(a) Explain why bacteria are useful in biotechnology.
…………………………………………………………………………………………………………………………………
(b) Insulin is one of many human proteins that are made by genetically engineered bacteria.
Some people cannot produce insulin because their immune system has destroyed the cells
that make insulin.
(i) State the organ that contains the cells that have been destroyed.
…………………………………………………………………………………………………………………….
(ii) State the name of the disease caused by the destruction of these cells.
…………………………………………………………………………………………………………………….
(iii) State the function of insulin in the body.
…………………………………………………………………………………………………………………….
(c) Genetically engineered bacteria that are used to make insulin were grown in a fermenter for
five days.
Samples were taken from the fermenter every six hours and the number of bacteria in 1.0 mm3
of the nutrient solution were counted.
Changes in the numbers of living bacteria in the samples taken from the fermenter are shown
in Fig. 3.1.
(i) Complete Fig. 3.1 by adding labels for the axes at 1 and 2 .
(ii) State the names of the stages of population growth of the bacteria labelled P to S.
P ……………………………………………………………………………………………………………………….
Q ………………………………………………………………………………………………………………………
R ……………………………………………………………………………………………………………………….
S ……………………………………………………………………………………………………………………….
(iii) Explain, with reference to Fig. 3.1, why the bacteria did not grow in the fermenter for
longer than five days.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
(d) Mineral salts are important in the human diet. One of the most important is iron.
Explain:
• the importance of iron in the human diet
• the effects of an iron deficiency.
…………………………………………………………………………………………………………………………………
(e) Fig. 3.2 shows a field of cassava, Manihot esculenta, which is a crop plant grown in parts of
Africa and Asia.
The plants store starch in their roots, which form a large part of the diet for many people.
Cassava does not provide many vitamins or mineral ions.
Genetic engineers have modified cassava to increase its iron content. They have done this
by incorporating a gene for a membrane protein from the plant Arabidopsis thaliana.
(i) State the name of the enzyme that is used to cut out the gene from the DNA of
A. thaliana.
…………………………………………………………………………………………………………………….
(ii) Describe how the gene from A. thaliana and the DNA from cassava form recombinant
DNA.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
(iii) Scientists who develop genetically engineered varieties of crop plants often breed them
for several generations before releasing them for farmers to use.
Suggest why the scientists do this.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
Answer/Explanation
Ans:
