A (23) | B (24) | C (45) | D (19) | E (25) | F (18) | G (15) | H (14) | I (14) | J (2) | K (2) | L (9) | M (15) | N (11) | O (10) | P (34) | Q (3) | R (22) | S (30) | T (14) | U (3) | V (9) | W (7) | Z (2)

A functional hereditary unit that occupies a fixed location on a chromosome and has a specific influence on heredity factors.

Genetic diversity

The total variety of hereditary characters found in a breeding population. Generally, the more unrelated animals in a breeding group, the greater will be the genetic diversity and the resulting viability of the herd as a whole.


The study of heredity; how characteristics are passed from parents to offspring.


A taxonomic concept used to group a number of species believed to be more closely related to one another than to any others; ranked between family and species.

Gestation period

The length of time for carrying the young in the womb. For example, a human has a gestation period of 9 months, cats and dogs have a gestation period of 63 days.


A body part that helps an animal get oxygen from water. Fish and many types of salamanders, newts, and caecilians have gills.


An enlargement of the alimentary canal in birds that serves to grind the food before it reaches the stomach.

Global warming

An increase in the average temperature of the Earth's atmosphere and oceans over time. This increase can cause changes in the Earth's climate that can affect habitats, and the plants and animals that live in them.


An animal that eats grain or seeds.


An area with grass and very few trees.


A pregnant animal.


To eat grasses and other ground-level plants.


A behavior seen primarily among primates in which individuals use their fingers and sometimes their teeth to comb through the fur of another individual. Not only does this activity help to maintain healthy fur and skin, but also promotes friendly communication among individuals, soothes emotions, and helps to establish bonds within the group. Other animals like birds and cats groom themselves as well.


Water lying below the Earth's surface in springs and natural reservoirs.

Guard hairs

The longer, stiffer hairs that grow up through the shorter, usually woolly hairs of a mammal's coat.