Characteristics of Living Things

What is a cell?

basic unit of structure and function of all living things

Unicellular

a single-celled oganism

Multicellular

composed of more than one cell

What characteristics do all living things share?

cellular organization, use energy, grow and develop, respond to their environment, reproduce

stimulus

change in an organism's surroundings that causes the organism to react

response

any reaction to a stimulus

spontaneous generation

false idea that living things arise from nonliving things

main chemicals found in cells

proteins, nucleic acids, carbohydrates, lipids and water

What are the 4 basic needs living things

energy, water, living space, and stable internal conditions

autotroph

organism that produces its own food

heterotroph

organism that cannot make its own food

homeostasis

process of maintaining a stable internal environment