QCAA definitions

carrying capacity

the size of a population that can be supported indefinitely on the available resources of an ecosystem

clade

a group of organisms that consists of a common ancestor and all its lineal descendants

ecological niche

the role and space an organism fills in an ecosystem, including all its interactions with the abiotic and biotic factors of the environment

evolution

the change in genetic composition of a population during sucessive generations which may result in the development of new species

gene

regions of DNA made up of nucleotides, molecular unit of heredity

genome

all genetic material of an organism

keystone species

plant or animal important for functions

macroevolution

large scale changes in allele frequencies, results in divergence of taxonomic groups.

microevolution

small allele frequencies variations, descent is of same taxonomic group as ancestor

polygenic inheritence

when one characteristic is controlled by two or more genes