iGCSE Biology (0610)-19.1 Energy flow - iGCSE Style Questions Paper 1

Question

A student measured the heights of her friends to see how they vary.

Which statements would apply to this type of variation?

1 A range of phenotypes between two extremes will be seen.
2 The variation will be caused by genes and the environment.
3 The variation will be caused by genes only.
4 There will be a limited number of phenotypes with no intermediates.

A 1 and 2
B 1 and 3
C 2 and 4
D 3 and 4

▶️ Answer/Explanation

Detailed solution

The correct answer is A

Height is an example of continuous variation, characterized by a smooth range of measurements rather than distinct categories. Consequently, Statement 1 is correct as there are infinite intermediates between the shortest and tallest heights. Statement 2 is also correct because continuous traits are polygenic and heavily influenced by environmental factors like nutrition. Statements 3 and 4 describe discontinuous variation, which does not apply to height. Thus, only 1 and 2 are accurate.

Question

The diagram shows the energy within the producers in an ecosystem and how much is transferred to primary consumers and eventually lost to the environment.

How much energy is transferred from primary consumers to secondary consumers?

(A) 5 kJ
(B) 50 kJ
(C) 500 kJ
(D) 5000 kJ

▶️ Answer/Explanation

The diagram shows that producers have 50,000 kJ. According to the 10% energy transfer rule in ecology, only about 10% of the energy is passed from one trophic level to the next. The energy reaching the primary consumers is 5,000 kJ (which is 10% of 50,000 kJ). Therefore, the energy transferred from primary consumers to secondary consumers would be 10% of 5,000 kJ, which equals 500 kJ. This is consistent with the typical energy pyramid model.

✅ Answer: (C)

Question

Black truffle is a fungus that obtains nutrients from the roots of hazel trees. Deer find and eat the fungi.
What is the source of energy for this food chain?

(A) deer
(B) hazel trees
(C) soil
(D) the Sun

▶️ Answer/Explanation

In any ecosystem, the ultimate source of energy is the Sun. Producers (plants like hazel trees) capture solar energy through photosynthesis and convert it into chemical energy stored in organic compounds. This energy is then transferred through the food chain: from the hazel trees to the black truffle (fungus, which acts as a consumer or decomposer depending on the relationship), and then to the deer. Soil provides nutrients and water but is not an energy source. Deer are consumers, not energy sources. Therefore, the Sun is the primary energy input for this and nearly all terrestrial food chains.
✅ Answer: (D) the Sun

iGCSE Biology (0610)-19.1 Energy flow – iGCSE Style Questions Paper 1

Question

Question

Question

Resources

Members

Company