Biology for IGCSE & O level - Variation And Selection (Section 6)
1
Which of the following processes results in the formation of new alleles?
Answer
(B)
Mutations
2
What factors influence the evolution of a population?
Answer
A
B
C
3
What is the main goal of selective breeding?
Answer
(B)
To improve the qualities of a species.
4
Weeds in the concrete jungle demonstrate that plants can adapt to their environment. The adaptation in the weeds growing in patches of soil around trees involved:
Answer
(B)
Producing heavier seeds that tend to fall vertically
5
What is the main driving force behind natural selection?
Answer
(B)
Environmental pressures
6
How does meiosis contribute to genetic variation?
Answer
(C)
Through the processes of crossing over and independent assortment, which leads to new combinations of alleles.
7
How does the environment influence variation within a population?
Answer
(D)
By influencing the phenotype (observable characteristics) of organisms.
8
Which of the following are examples of natural selection?
Answer
A
B
C
9
How do organisms that compete for resources survive?
Answer
(B)
By exhibiting traits that are most suited to their environment.
10
Which of the following factors can influence the growth of plants?
Answer
A
B
C
D
11
What are the benefits of outbreeding in artificial selection?
Answer
(A)
It increases hybrid vigor.
12
Which of the following statements best describes the effect of a mutation?
Answer
(C)
Mutations can be beneficial, harmful, or neutral.
13
In the context of the text, what is meant by 'hybrid vigor'?
Answer
(C)
The hybrid offspring showing better traits.
14
In the example of weed seeds in the concrete jungle, what environmental factor favored the evolution of heavier seeds?
Answer
(D)
Proximity to the parent plant
15
How does natural selection result in changes in a population?
Answer
(B)
By increasing the frequency of advantageous traits.
16
Which condition is required for natural selection to lead to adaptation in a population?
Answer
A
C
17
Which of the following is an example of an adaptive feature?
Answer
(B)
The long neck of a giraffe
18
What are the main ways in which natural selection can affect a population?
Answer
A
B
D
19
What is a defining characteristic of discontinuous variation?
Answer
(B)
Distinct, separate categories.
20
What is the main purpose of outbreeding in artificial selection?
Answer
(D)
To improve the overall vigor of offspring.
21
In the text provided, what is one example of a scenario where natural selection is taking place?
Answer
A
B
C
22
In natural selection, what is the role of heritable traits?
Answer
(D)
All of the above.
23
Which statement best differentiates artificial selection from natural selection?
Answer
(C)
Artificial selection is driven by human choice; natural selection by environmental factors.
24
What is the definition of 'fitness' in evolutionary biology?
Answer
(B)
An organism's ability to survive and reproduce.
25
What can cause a mutation?
Answer
A
B
C
26
In which of these ways does natural selection influence the distribution of traits within a population?
Answer
A
D
27
How does natural selection lead to evolution?
Answer
(C)
By increasing the frequency of advantageous traits.
28
What is the primary role of humans in artificial selection?
Answer
(B)
To act as the selective agent.
29
In what way does variation in a population provide the foundation for natural selection?
Answer
(C)
It gives the environment something to select against or select for.
30
In the context of natural selection, what is meant by 'fitness'?
Answer
(C)
An organism's reproductive success.
31
What is the ultimate outcome of natural selection acting on a population over many generations?
Answer
(C)
Evolution
32
Which of the following is NOT a cause of genetic variation within a population?
Answer
(D)
Environmental factors
33
What is the term used to describe a change in the sequence of bases in DNA?
Answer
(C)
Mutation
34
What impact does a change in environmental conditions have on a population?
Answer
A
C
35
In natural selection, what is the significance of advantageous traits?
Answer
(C)
They increase an organism's reproductive success.
36
What are the key components that make an adaptive feature?
Answer
(B)
A trait that improves survival or reproduction.
37
Which of the following is an example of a discontinuous variation?
Answer
(B)
Eye color
38
In a population of fish, some individuals have a slightly different fin shape. This variation in fin shape is an example of what?
Answer
(C)
Variation.
39
Which of the following scenarios best represents natural selection?
Answer
(D)
A population of insects evolving resistance to a pesticide.
40
Which of the following is an example of continuous variation?
Answer
(C)
Finger length
41
Which factor contributes to variation within a species?
Answer
A
B
C
42
What is a possible outcome of inbreeding?
Answer
(D)
Increased expression of harmful recessive traits.
43
What causes the 'shuffling' of alleles during meiosis?
Answer
(B)
Independent assortment and crossing over
44
Which statement best describes the relationship between natural selection and adaptation?
Answer
(A)
Natural selection is a process; adaptation is the result.
45
Which of the following is an example of natural selection?
Answer
(C)
A population of insects developing resistance to a pesticide.
46
What is the main driver of evolution according to the principles of natural selection?
Answer
(D)
The survival of individuals with the most offspring
47
If a population of bacteria is exposed to an antibiotic, what will happen to the bacteria that are resistant to the antibiotic?
Answer
(D)
Their numbers will increase.
48
What is the process that results in offspring having a unique combination of traits, compared to their parents?
Answer
(C)
Sexual reproduction
49
What is a potential negative consequence of selective breeding?
Answer
(C)
Increased susceptibility to disease.
50
What type of graph is most appropriate for displaying continuous variation data?
