Organisms that are better adapted to their environment are more likely to survive, reproduce and pass on their genes to their offspring.

Microscopic living thing, such as a bacterium or an amoeba.

A change in the nucleotide base sequence in the DNA of the genome.

A region of DNA in which the sequence of nucleotide bases has been changed.

A form of reproduction in which a cell divides to produce two genetically identical cells.

Mutations and evolution in bacteria

Combined science

Pupils will learn about eukaryotic and prokaryotic cells, and that subcellular evidence, including from analysis of genomes, has led to the classification and sometimes reclassification of organisms into taxonomic groups from species to domains.

Pupils learned that the fossil record provides evidence of evolution from common ancestors through transitional species to modern species, and that the theory of evolution by natural selection can be used to explain phenotypic changes in populations of species over generations.

Variation and natural selection at the genetic level

Microscopic living things such as bacteria and amoeba are known as {{}}.

Andeep: All living organisms evolve, including microorganisms.

Jun: Only humans and other animals such as finches and tortoises evolve.

Laura: Animals and plants evolve, but bacteria don’t because they’re too small.

The Oak pupils are discussing evolution. Who is correct?

Bacteria divide to make two identical cells in the process of {{}} reproduction.

True or false? Some antibiotics have evolved to be resistant to bacteria.

Bacteria can gain a new ability when mutation in their DNA creates a new ...

Alex: Many bacteria have deliberately evolved to try to kill us!

Izzy: It’s just random. New abilities just appear because of random mutations.

Sam: Some bacteria have evolved new abilities because they want to help us.

The Oak pupils are discussing evolution in bacteria. Who is correct?

True or false? Bacteria are living organisms.

True or false? All bacteria are harmful to humans because they cause diseases.

… changes in an organism’s characteristics during its lifetime.

… changes in the common characteristics of a species over generations.

… passing genetic information from one generation to the next.

a region of DNA in which the nucleotide base sequence has been changed

a process that changes the nucleotide base sequence in a region of DNA

the process by which most scientists believe evolution occurs

Match each keyword to its correct definition.

A mutation changes the nucleotide base sequence in the organism’s DNA.

Variation is caused by the changes in the nucleotide base sequence in the DNA.

This may cause the organism to have a new adaptation, giving it an advantage.

The organism competes more successfully for food and other resources.

The organism is more likely to survive and reproduce.

The genetic variant made by the mutation is passed to the organism’s offspring.

Put the steps in the correct order to explain how an organism evolves by natural selection.

Starter Quiz