CIE iGCSE Co-Ordinated Science B17.2 Selection Exam Style Questions Paper 1
Question
Selection in chickens has produced individuals that lay more eggs per week.
What is required for this to occur?
▶️Answer/Explanation
Ans :A
Question
Natural selection involves several stages.
1. passing on alleles to the next generation
2. struggle for survival
3. competition for resources
4. production of many offspring
What is the correct order of these stages?
A \( 4 \to 1 \to 2 \to 3 \)
B \( 4 \to 3 \to 2 \to 1 \)
C \( 1 \to 2 \to 3 \to 4 \)
D \( 3 \to 2 \to 1 \to 4 \)
▶Answer/Explanation
Answer: B
Explanation: The correct order of stages in natural selection is:
1. Production of many offspring (4)
2. Competition for resources (3)
3. Struggle for survival (2)
4. Passing on alleles to the next generation (1)
This sequence reflects the process of natural selection, where organisms produce many offspring, compete for limited resources, struggle to survive, and those with advantageous traits pass on their alleles to the next generation.
Question
Selective breeding is used to improve crop plants. What does it involve?
A. artificial selection
B. asexual reproduction
C. ionising radiation
D. natural selection
▶️Answer/Explanation
Answer: A. artificial selection
Explanation: Selective breeding involves the intentional selection of plants or animals with desirable traits to produce offspring with those traits. This process is also known as artificial selection, as it is controlled by humans rather than occurring naturally.
Question
A farmer wants to breed sheep that will produce a high yield of milk. What is required for breeding these sheep?
| genetic variation | selective breeding | natural selection | |
|---|---|---|---|
| A | ✓ | ✓ | x |
| B | ✓ | x | ✓ |
| C | x | ✓ | x |
| D | x | x | ✓ |
Key: ✓ = yes, x = no
▶️Answer/Explanation
Answer: A
Explanation: To breed sheep that produce a high yield of milk, the farmer needs genetic variation and selective breeding. Genetic variation provides the diversity needed for selective breeding, which involves choosing and mating individuals with desirable traits (high milk yield in this case). Natural selection is not required as it is a process that occurs in nature without human intervention.
Question
The graph shows the number of cows producing different volumes of milk. Which group of cows should be used in a programme to breed more cows with the highest milk yield?
▶️Answer/Explanation
Answer: D. D
Explanation: The group of cows with the highest milk yield (group D) should be selected for breeding to ensure that the offspring inherit the trait for high milk production. This is an example of selective breeding.