to evaluate or determine the amount of.
imaginary line around the Earth, another planet, or star running east-west, 0 degrees latitude.
migration route regularly used by birds, bats, or butterflies.
material, usually of plant or animal origin, that living organisms use to obtain nutrients.
system of satellites and receiving devices used to determine the location of something on Earth.
to acquire a habit or behavior through a learning process that occurs early in the life of a social animal, usually through an association with a parent or role model.
a prominent feature that guides in navigation or marks a site.
distance north or south of the Equator, measured in degrees.
area around and affected by a magnet or charged particle.
to move from one place or activity to another.
to plan and direct the course of a journey.
part of the nervous system that registers sensation and touch.
impulse-conducting cell found in the nervous system. Also called a nerve cell and neurocyte.
having to do with smell or the sense of smell.
group of tissues that perform a specialized task.
to position or find the location of something.
study of activity in living organisms, including physical and chemical processes.
extreme north or south point of the Earth's axis.
topographic features of an area.
study of the shape of the surface features of an area.
state of the atmosphere, including temperature, atmospheric pressure, wind, humidity, precipitation, and cloudiness.
repeating or predictable changes in the Earth's atmosphere, such as winds, precipitation, and temperatures.