CIE iGCSE Co-Ordinated Science B19.1 Habitat destruction Exam Style Questions Paper 1
Question
What is an undesirable effect of deforestation?
(A) It increases the oxygen concentration of the atmosphere.
(B) It leads to erosion and loss of soil.
(C) It makes land available for agriculture.
(D) It pollutes the air with methane.
▶️Answer/Explanation
Ans: B
Question
What is an undesirable effect of deforestation?
(A) It increases the oxygen concentration of the atmosphere.
(B) It leads to erosion and loss of soil.
(C) It makes land available for agriculture.
(D) It pollutes the air with methane.
▶️Answer/Explanation
Ans: B
Question
What is an undesirable effect of deforestation?
(A) It increases the oxygen concentration of the atmosphere.
(B) It leads to erosion and loss of soil.
(C) It makes land available for agriculture.
(D) It pollutes the air with methane.
▶️Answer/Explanation
Ans : B
Question
Which row about the effects of deforestation is correct?
▶️Answer/Explanation
Ans : D
Question
Which row describes the effects of deforestation?
▶️Answer/Explanation
Ans: D
Question
Forests are cut down and burnt in deforestation programmes.
As a result of this, which gas in the atmosphere increases in concentration?
(A) carbon dioxide
(B) hydrogen
(C) nitrogen
(D) oxygen
▶️Answer/Explanation
Ans : A
Question
The graph shows changes during eutrophication.
What could be the label for the vertical (y) axis?
1. growth of producers
2. number of aerobic bacteria
3. rate of decomposition
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2 and 3
▶️Answer/Explanation
Answer: D. 1, 2 and 3
Explanation: During eutrophication, the growth of producers (algae and plants) increases, leading to an increase in the number of aerobic bacteria and the rate of decomposition as organic matter accumulates. Therefore, all three labels could be correct for the vertical axis.
Question
The diagram shows a river and four farms. The numbers in the river show relative oxygen concentrations.
From which farm is untreated sewage leaking into the river?
▶️Answer/Explanation
Answer: D. Farm 4
Explanation: Untreated sewage reduces the oxygen concentration in water. The farm with the lowest oxygen concentration downstream is likely the source of the pollution, which is Farm 4.
Question
What could deforestation cause?
A. a decrease in carbon dioxide levels and a decrease in flooding
B. a decrease in carbon dioxide levels and an increase in flooding
C. an increase in carbon dioxide levels and a decrease in flooding
D. an increase in carbon dioxide levels and an increase in flooding
▶️Answer/Explanation
Answer: D. an increase in carbon dioxide levels and an increase in flooding
Explanation: Deforestation leads to an increase in carbon dioxide levels because trees absorb CO₂ during photosynthesis. It also increases the risk of flooding because trees help absorb rainwater and reduce runoff.
Question
Untreated sewage is released into a river at point X. Which graph correctly shows changes in oxygen concentration of the water as the river flows away from X?
▶️Answer/Explanation
Answer: B. Graph B
Explanation: When untreated sewage is released into a river, it leads to an increase in the growth of bacteria, which consume oxygen. This causes a decrease in oxygen concentration near point X, followed by a gradual recovery as the river flows away from X. Graph B shows this pattern.
Question
A pupil listed some undesirable effects of deforestation.
- increase of carbon dioxide in the atmosphere
- extinction of species
- flooding
- increased number of habitats
Which effects are correct?
A. 1, 2, 3 and 4
B. 1, 2 and 3 only
C. 1, 2 and 4 only
D. 2, 3 and 4 only
▶️Answer/Explanation
Answer: B
Explanation: Deforestation leads to an increase in carbon dioxide levels, extinction of species, and increased flooding due to the loss of trees. It does not increase the number of habitats; instead, it destroys them.