Question
Elk are mammals and they are herbivores. The graph shows the total number of elk in a national park between 1978 and 2008.
What is a possible explanation for the change in the elk population between 1978 and 1992?
(A) decrease in disease
(B) decrease in food source
(C) increase in hunting
(D) increase in predation
▶️Answer/Explanation
Ans: A
Question
A fruit grower wants to develop a new disease-resistant fig tree with tastier fruit.
She crosses two fig trees and plants the seeds that are produced.
She chooses the best plant that grows from the seeds and takes cuttings from it. The cuttings grow into trees that are identical to the chosen plant.
Which processes are involved?
(A) selective breeding, involving sexual reproduction followed by asexual reproduction
(B) natural selection involving selection of individuals best adapted to the environment
(C) sexual reproduction resulting in natural selection
(D) asexual reproduction resulting in selective breeding
▶️Answer/Explanation
Ans: A
Question
What is needed for natural selection to take place?
(A) excess resources for the population
(B) no variation within a population
(C) reproduction by individuals that are better adapted to the environment than others
(D) selection by humans of organisms with desired characteristics
▶️Answer/Explanation
Ans: C
Question
Humans have kept sheep for many centuries because they supply us with wool.
The flow chart shows how a farmer would breed his sheep to provide more wool.
Which process is described by this flow chart?
A natural selection
B selective breeding
C struggle for survival
D genetic modification
▶️Answer/Explanation
B selective breeding