7.3 | Natural Selection

What is a mutation?

• A change to an organism's appearance

• A change to an organism's behaviour

• A change to an organism's genetic material

How can you increase the risk or rate of mutation?

• By natural selection

• By Radiation

• By Variation

What can cause variation?

• Changes in the environment

• Mutation

• Isolation

What can cause variation to be passed on to offspring?

• Less well-adapted individuals cannot reproduce

• Most well-adapted individuals can reproduce

• Reproduction involves passing on genes

What are the only types of characteristics that can be passed on by inheritance?

• Those that make an organism more likely to survive and reproduce

• Those that are present in all the organisms in a population

• Those that are the result of the genes an organism possesses

What is meant when an organism is described as having a 'selective advantage'?

• The organism can change to help it survive and reproduce in its environment

• The organism has characteristics that help it to survive and reproduce in its environment

• The organism is unable to survive and reproduce in its environment

Which of the following is an example of evolution by natural selection?

• A giraffe increasing its neck length by stretching to reach the top of a tree

• A human increasing the size of their muscles as a result of training

• An increase in the number of drug resistant bacteria in a population

Which of the following is an example of a selection pressure?

• Competition for food

• Mutation

• Variation

A population of rabbits grows rapidly from one year to the next. Then one year, a disease strikes approximately one fourth of the adult rabbits. The disease remains with the population in the years that follow.

As explained by Darwin’s theory, which of these conditions allows the rabbit population to evolve by natural selection?

• The disease affects adult and juvenile rabbits equally.

• The disease reduces the ability of the rabbits to reproduce.

• Some rabbits are resistant to the disease, and they pass the resistance to their offspring.

• No rabbits are resistant to the disease, and all die when the disease strikes them.

Which of the following is a situation that could cause evolutionary change that is NOT due to natural selection?

• A volcano erupts and kills many individuals in a population.

• A mutation produces sea stars that are less visible to predators.

• An insecticide is sprayed in a community to combat mosquitoes.

• Cattle are treated with antibiotics to prevent the spread of infections.