CIE iGCSE Co-Ordinated Science B17.1 Variation Exam Style Questions Paper 1
▶️ Answer/Explanation
Human height is an example of continuous variation, where traits show a range of values between two extremes.
This produces a bell-shaped curve (normal distribution) when plotted as a graph. Most individuals are of average height, with fewer at the extremes.
✅ Answer: (A)
This produces a bell-shaped curve (normal distribution) when plotted as a graph. Most individuals are of average height, with fewer at the extremes.
✅ Answer: (A)
▶️ Answer/Explanation
Type Y potatoes display a bell-shaped (normal distribution) curve of masses, indicating a continuous range of values with no clear divisions — this is the hallmark of continuous variation.
Type Z may overlap in range with Y, so we cannot conclude Z are always smaller; and discontinuous variation would show distinct separate bars, not a smooth curve.
✅ Answer: (B)
Type Z may overlap in range with Y, so we cannot conclude Z are always smaller; and discontinuous variation would show distinct separate bars, not a smooth curve.
✅ Answer: (B)
▶️ Answer/Explanation
Continuous variation describes characteristics, such as height, that can take any value across a range rather than falling into distinct categories.
This range extends between two extreme values, with every intermediate value possible, unlike discontinuous variation which has no intermediates.
So the correct definition is a range of phenotypes between two extremes.
✅ Answer: (C)
This range extends between two extreme values, with every intermediate value possible, unlike discontinuous variation which has no intermediates.
So the correct definition is a range of phenotypes between two extremes.
✅ Answer: (C)
▶️ Answer/Explanation
Variation is the biological term for differences seen between individuals of the same species.
These differences can arise from genetic factors, environmental factors, or a combination of both.
Competition, generation and selection describe different biological processes, not this concept.
✅ Answer: (D)
These differences can arise from genetic factors, environmental factors, or a combination of both.
Competition, generation and selection describe different biological processes, not this concept.
✅ Answer: (D)
▶️ Answer/Explanation
A characteristic with a full range of values between two extremes (such as size or height) is continuous variation.
Discontinuous variation instead produces distinct, separate categories (e.g. blood group), which does not match “a range between two extremes”.
✅ Answer: (A)
Discontinuous variation instead produces distinct, separate categories (e.g. blood group), which does not match “a range between two extremes”.
✅ Answer: (A)