CB4b - Darwin's theory

• An ancestor is an organism from which more recent organisms are descended
• Antibiotics are medicine that helps people recover from bacterial infection by killing the pathogen.
• There is competition between organisms that need the same things as each other (such as food).
• Genetic variation is differences between organisms caused by differences in the genes they inherit from their parents.
• Genetic variation is also known as inherited variation.
• Natural selection is a process in which certain organisms are more likely to survive than other members of the same species.
• Resistant means unaffected or less affected by something.