Chapter 17 Variation And Selection Flashcards
Define variation:
The differences between the individuals of the same species
Define discontinuous variation:
Variation in which there are distinct categories of phenotype, with no intermediates
Define population:
A group of organisms of one species, living in the same area at the same time
Define continuous variation:
Variation in which there is a continued range of phenotypes between two extremes
Define mutations:
A random change in the gene, which can produce new alleles
Mutation involves a change in the base sequence in DNA
Define adaptive feature:
An inherited feature that helps an organism to survive and reproduce in its environment
Define xerophyte:
A plant that has adaptive features that help it to survive in an environment where water is scarce
Define hydrophyte:
A plant that has adaptive features that helped to survive in water
Define natural selection:
A process in which individuals with advantageous features are more likely to survive, reproduce and pass on their alleles to the next generation
Define selection pressure:
Something in the environment that affects the chance that individuals with different features will survive and reproduce
Define adaption:
The process, resulting from natural selection, by which population become more suited to their environment over many generations
Define drug:
Any substance taken into the body that modifies or affects chemical reactions in the body
Define antibiotic:
A substance that is taken into the body, and which kills bacteria but does not affect human cell/viruses
Define MRSA:
Methicillin-resistant Staphylococcus aureus
Bacteria that are resistant to the antibiotic methicillin
Define artificial selection/selective breeding:
Choosing particular organisms with desired characteristics to breed together, and continuing this over many generations
