Characteristics of life

Movement

change in position

Responsiveness

sense changes and react

Growth

increase in size

Reproduction

producing offspring

Respiration

obtaining oxygen

Digestion

breaking down food

Absorption

passing digesting products through membranes

Circulation

movement of substances

Assimilation

changing substances

Excretion

removal of wastes

Metabolism

all the chemical changes that occur in the body

Energy

the capacity to do work

Homeostasis

maintaining the same internal environment

Receptors

senses that detect environmental conditions

Effectors

glands that respond to changes in the environment

Negative feedback loop

returns conditions to a set point (like a thermostat)

Positive feedback loop

amplifies occurrences, like the production of milk