stage in human development commonly accepted to be between the ages of 3-5 years.

the polished appearance of a bone due to cartilaginous damage and the contact of bone to bone at a joint.

the place that an organism or a group of organisms occupies in an ecosystem and its interactions with the surrounding environment.

the study of the relationship between an organism and the surrounding environment.

a unit in ecology that consists of organisms and non-living objects that may affect the environment.

lower, false rib.

eight vertebra forming the mid back.

lower, floating rib.

eleventh vertebra forming the mid back.

a very hard substance that covers the dentine on the crown of a tooth.

the size of the space in the cranium where the brain sits.

a geographically defined area that includes its geological and ecological settings and the biological organisms that inhabit the area.

the second center of ossification in long bones; separated from the shaft by an epiphyseal plate.

Sievelike bone which forms part of the bony nose.

the cause of a disease or abnormal condition

when the sole of the foot is turned laterally; the opposite of inversion.

descent through genetic modification; a change in gene allele frequencies from one generation to the next.

an evolved character whose current use is not the same as its original use.

species that are living, opposite of extinct.

a movement to increase the angle between a joint; see also flexion.

a species that no longer exists; may only be identifiable through the fossil record or eye witness accounts. Some animals have gone extinct in the historical period.