Variation Flashcards – AQA GCSE Biology - Foundation (8461)

What is a mutation?

A change in genetic material.

How often do mutations occur?

Continuously.

What is the ultimate source of genetic variants?

Mutations.

How can inherited variants contribute to differences between individuals?

They can contribute to genetic differences between individuals.

What effect do most mutations have on phenotype?

Most have no effect on phenotype.

How do genetic variants influence characteristics, relative to environmental factors?

Some influence a characteristic, often alongside environmental factors; very few determine one on their own.

How often does a mutation lead to a new phenotype?

Very rarely.

What is an organism's phenotype?

Its observable characteristics.

What is an organism's genome?

Its complete set of genetic material.

How does an organism's genome influence its characteristics?

Through the information carried by its genes.

How can environmental conditions affect an organism's characteristics?

They can affect how characteristics develop or are expressed.

How are genetic and environmental influences related in determining phenotype?

Phenotype reflects their interaction, rather than being determined by either alone.

When can a new, heritable phenotype become advantageous?

When an environmental change makes it better suited to the conditions.

How can an advantageous heritable phenotype affect an individual’s survival and reproduction?

The individual may be more likely to survive and reproduce, passing the associated genetic variant to offspring.

How can selection affect the frequency of an advantageous phenotype and its associated genetic variant over generations?

Both can become more common in the population.

How quickly can selection of an advantageous new phenotype change a species?

It can cause a relatively rapid change.