What is variation caused by?
Environmental factors only.
Environmental and genetic factors.
Genetic factors only.
Which type of variation is human blood groups an example of?
Continuous.
Discontinuous.
Both continuous and discontinuous.
According to Darwin’s theory of evolution, how do new species evolve?
By natural selection.
By unnatural selection.
By selective breeding.
Which individuals are most likely to survive to reproduce?
Those well suited to their environment.
Those poorly suited to their environment.
Those that have no immunity to new diseases.
Why might antibiotic resistance develop in populations of bacteria?
More effective antibiotics can be developed over time.
The antibiotics change over time and become less effective.
Mutations in individual bacteria protect them from the antibiotic, letting them reproduce while others are killed.
Which type of variation can be passed on to the next generation?
Genetic variation.
Environmental variation.
Genetic and environmental variation.
Which statement about the effects of mutations is correct?
All mutations are harmful.
Some mutations are beneficial.
All mutations cause some effect.
What is a mutation?
A random change in the number of chromosomes.
A rare change in the structure of a nucleus.
A change in appearance.
What has provided evidence for evolution?
Fossil fuels.
Fossils.
There is no evidence.
What can happen if a species fails to adapt to environmental changes?
It can become endangered.
It can become extinct.
Its population number can increase.