Topic 5.2: Natural Selection

What would restrict evolution by natural selection, if a species only reproduced by cloning?

• Too few offspring would be produced.

• Mutations could not occur.

• The offspring would show a lack of variation.

• The offspring would be the same sex as the parent.

What is the reason for antibiotics not damaging human cells?

• The dose is too small to be harmful.

• The dose is taken for only a short time.

• Antibiotics occur naturally in humans.

• Human metabolism is different from bacterial metabolism.

Balkan green lizards, Lacerta trilineata, living in mainland Greece eat mostly insects but also small amounts of plants. The same species living on Greek islands (where insects are scarce) show a greater percentage of those physical traits useful for eating plants than the mainland lizards. What is the biological explanation for these observations?

• Variation in each lizard population allowed adaptation to occur.

• Lizards migrated to areas where they were better adapted.

• Lizards on the islands diverged due to lack of interbreeding with the mainland population.

• Homologous structures have prevented separate species from evolving.

What causes variation within a population?

• Fertilization and change in the environment

• Fertilization and mutation

• Mutation and evolution

• Evolution and adaptive radiation

A bacterial population with no resistance to an antibiotic may develop into a bacterial population with some resistance to an antibiotic. Which event could lead to this?

• Antibiotic resistance was inherited from an ancestral population.

• An antibiotic resistance plasmid is received from a bacterium in another population.

• The enzyme needed for antibiotic resistance is received from a bacterium in another population.

• The bacterial population mutated in response to antibiotics in the environment.

What is a direct consequence of the overproduction of offspring?

• Individuals become more adapted to the environment.

• They will be subject to intraspecific competition.

• They will diverge to produce different species.

• They will suffer mutations.

Lichens are returning to the forests of the industrial areas of the United Kingdom due to strict pollution control. What is the expected outcome in the population of peppered moths (Biston betularia)?

• Increased numbers of light-coloured peppered moths

• Increased industrial melanism in peppered moths

• Increased predation of peppered moths

• Increased speciation of peppered moths

What is the major contributor to the increase in antibiotic resistance in bacteria?

• Sexual reproduction

• Mutation

• Natural selection

• New antibiotics

Which process promotes variation in a population?

• Mutation

• Mitosis

• Ageing in a population

• Asexual reproduction

Darwin described evolution as “descent with modification”. What would make evolution less probable?

• Stable environment

• Migration

• Variation in offspring

• Random mutation