Evidence for evolution Flashcards – AQA GCSE Combined Science: Trilogy (8464) — Biology — Foundation

What genetic variation can make some bacteria resistant to an antibiotic?

Some bacteria carry an allele that confers resistance to the antibiotic.

How does an antibiotic affect the survival and reproduction of susceptible and resistant bacteria?

Susceptible bacteria are more likely to die; resistant bacteria are more likely to survive and reproduce.

How is an antibiotic-resistance allele passed to the next bacterial generation?

Surviving bacteria pass the allele to their offspring.

How can an antibiotic-resistant bacterial strain arise over many generations?

Resistant bacteria can become more common in the population, producing a resistant strain.

What is a fossil?

The preserved remains or traces of an organism that lived in the past.

What do fossils in rocks of different ages reveal?

Which organisms lived at different times.

What do comparisons of fossils with one another and with living organisms show about life over time?

Life has changed over time.

What can similarities between fossils and living organisms indicate about ancestry?

They are consistent with common ancestry.

What are two reasons the fossil record is incomplete?

Fossilisation occurs only in particular conditions, and geological processes can destroy fossils.

Which widely accepted theory do fossils support alongside other evidence?

The theory of evolution by natural selection.

What is a gene?

A section of DNA that carries information influencing characteristics.

What is an allele?

A version of a gene.

How can genes contribute to inherited differences between offspring?

Offspring inherit alleles from their parents, and different alleles can contribute to inherited differences.

When can natural selection change how common an allele is over generations?

When an inherited difference associated with the allele affects survival or reproduction.