Biology for IGCSE & O level - Variation And Selection (Section 1)
1
In the context of the plant with the perch, how does the branchless stem benefit the plant?
Answer
(C)
It makes it easier for birds to access nectar, facilitating pollination.
2
What is an advantage for the plant to develop flowers which has a perch, enabling them to push their beaks into the red flowers to drink nectar and at the same time pollinate the plant?
Answer
(B)
The plants gain a selective advantage.
3
In the context of the weeds in the concrete jungle, what is the environmental pressure that favors the evolution of heavier seeds?
Answer
(B)
Limited soil availability in the parent plant's vicinity
4
What is the definition of gene?
Answer
(A)
A segment of DNA that codes for a specific trait.
5
Which type of selection produces the Merino sheep?
Answer
(B)
Artificial Selection
6
Which of the following is an example of natural selection?
Answer
(B)
A plant developing a resistance to a new herbicide.
7
In a population, which individuals are most likely to pass on their traits to the next generation according to natural selection?
Answer
(A)
Those with traits that allow them to survive and reproduce.
8
How does a new allele arise in a population?
Answer
(C)
Through mutation.
9
What is the definition of variation in biology?
Answer
(B)
The differences between individuals of the same species.
10
What happens to the individuals with the best adapted traits in the environment?
Answer
(A)
They will survive and reproduce.
11
Which of the following creates genetic variation?
Answer
(C)
Mutation
12
What is the most likely reason that the tomcod fish developed resistance to PCBs?
Answer
(B)
A mutation arose that protected them from the PCBs.
13
What is one potential downside of selective breeding?
Answer
(C)
A reduction in disease resistance.
14
In selective breeding, what is the role of humans?
Answer
(A)
They select the best traits to breed for the next generation.
15
Which of the following would be an example of a trait that may be improved through selective breeding?
Answer
(B)
The increased yield of grain in a crop.
16
What type of graph is used to show continuous variation?
Answer
(C)
A histogram
17
Which of the following is required for natural selection to work?
Answer
A
B
C
18
Which of the following terms best describes what is meant by the term hybrid vigour?
Answer
(C)
The enhanced vigour of offspring resulting from outbreeding.
19
Which of the following is a factor that causes the struggle for survival?
Answer
(D)
All of the above
20
What is the process of natural selection based on?
Answer
(B)
Individuals with the best adaptations being most likely to survive and reproduce.
21
Which of the following is an example of a discontinuous variation?
Answer
(C)
Blood groups in humans
22
Which of the following shows the effect of a gene mutation?
Answer
(B)
A change in the phenotype.
23
What is the main role of the 'struggle for existence' in natural selection?
Answer
(C)
To drive competition and selection.
24
Which statement best describes the meaning of phenotype?
Answer
(B)
The observable traits of an organism.
25
What would happen if an organism had an advantageous feature?
Answer
(A)
It is more likely to survive and reproduce.
26
What is the role of 'competition' in natural selection?
Answer
(C)
To determine which individuals are best suited for survival and reproduction.
27
Which of the following is an example of an adaptation?
Answer
(C)
The long neck of a giraffe
28
What is the process where an organism's genetic constitution determines the range of forms found in a species?
Answer
(B)
Variation
29
Which statement best describes what happens to an organism with adaptive features?
Answer
(B)
It is more likely to survive and reproduce.
30
Which of the following is a result of natural selection?
Answer
(B)
An increase in antibiotic resistance.
31
Which factor is likely to cause the beetles' different colours?
Answer
(C)
Beetles are well camouflaged so that predators cannot see them.
32
What is the ultimate source of new genetic variation?
Answer
(C)
Mutation
33
How can the environment influence the phenotype of an organism?
Answer
(B)
By influencing the expression of genes.
34
What type of data is best displayed using a histogram?
Answer
(C)
Data showing continuous variation
35
Which of these is an example of continuous variation?
Answer
(C)
The height of human beings
36
What does 'inheritance' mean in the context of natural selection?
Answer
(B)
The passing of traits from parents to offspring.
37
Which of the following is an example of an adaptive feature that helps plants survive in the aquatic environment?
Answer
(C)
Air spaces in stems
38
Which of the following is an example of an environmental factor influencing variation?
Answer
(C)
Height influenced by nutrition
39
What is the source of new alleles within a population?
Answer
(C)
Mutation
40
Which of the following are key differences between artificial and natural selection?
Answer
A
B
C
41
Which type of variation can be affected by environmental factors?
Answer
(B)
Continuous
42
What is the ultimate source of new genetic variation in a population, upon which natural selection can act?
Answer
(B)
Mutation
43
What is a gene mutation?
Answer
(B)
A change in the DNA sequence.
44
Which of the following best describes how natural selection causes changes in a population?
Answer
(C)
Individuals with beneficial traits survive and reproduce more.
45
In selective breeding, what is the primary goal?
Answer
(B)
To produce organisms with desired traits.
46
What type of variation is demonstrated by the different blood groups found in humans?
Answer
(B)
Discontinuous variation
47
Which of the following is a result of natural selection?
Answer
(C)
Change in a species over time
48
What is the main driving force behind natural selection?
Answer
(B)
The survival of the fittest in a competitive environment.
49
What is the significance of a mutation in a sex cell?
