SCIENCE TEST 2

adaptive radiation

The rapid divergence of an evolutionary lineage from a recent common ancestor.

analogous structures

Structures that appear similar or have the same function, even though the individuals are unrelated.

artificial selection

The process by which people choose to breed particular organisms with desirable features; also known as selective breeding.

biodiversity

The number and range of species that exist on Earth or in an ecosystem.

biogeography

The study of the geographic distribution of organisms.

comparative anatomy

The science of comparing the structure of a species with others and looking for similarities and differences.

cross-breeding

Selective breeding by combining in the offspring a desirable feature of one individual with a different desirable feature in another individual.

descendant

A species or group that evolves from an ancestor.

distribution

A map of all the places where a species occurs.

genome

The full set of chromosomes present in the nuclei of normal cells of a species; the study of the structure, function, evolution and mapping of the genome is called genomics.

geographical distribution

All the places on Earth where a particular species is found.

Homo

The genus to which modern human beings, and several other extinct species, belong.

homologous structures

Similar structures in related individuals.

hybrid

An individual produced by a cross between parents with different genotypes.

isolation

Keeping interbreeding groups apart by some barrier or mechanism.

mitochondrial DNA

DNA contained within the cell mitochondria and passed from mother to sons and daughters.

morphology

The physical form or structure of an organism.

natural selection

The process in which an environmental factor acts on a population and results in some organisms having more offspring that survive to reproduce than others.

nucleotide

A molecule consisting of a five-carbon sugar, a nitrogenous base, and a phosphate group; the main building blocks of nucleic acids.

Out of Africa model

A model (hypothesis) proposing that a common ancestor of all modern humans evolved in Africa and then migrated out to colonise the whole Earth.

phylogenetic tree

A branching diagram that depicts the evolutionary relationships of organisms.

primates

An order of animals with ‘grasping’ hands, nails rather than claws, and forward-facing eyes.

resistance

The inherited ability of a species to withstand chemicals such as pesticides.

selection pressure

The effect of the selective agent on a population.

selective agent

An environmental factor that acts on a population during natural selection.

inbreeding

selective breeding between two closely related individuals