Stimuli

Catching a ball at a baseball game

Drinking when you are thirsty

Running at the sight of a wild lion

Writing a thank you note

outside reaction that monitor your bodily systems

the temperature of the body

food that gives your body energy

A thing of even that causes a reaction

A negative response to a stimulus

a learned behavior

gravitropism

phototropism

A plant's growth response toward light

A plant's growth response to gravitation

A plant wilting when the soil dries out

A plant making sugar through photosynthesis

Only multicellular organisms maintain homeostasis.

Without receptors, an organism cannot maintain homeostasis.

Learned behaviors are not important for an organism to maintain homeostasis.

Plants only need to respond to internal stimuli to maintain homeostasis.

Options

• An external stimulus comes from outside the organism. Animals respond to stimuli through learned behaviors and instinct.

Stimuli trigger responses in organisms that allow them to maintain constant internal conditions through homeostasis.

Homeostasis is a set of mechanisms that work to maintain stable internal conditions as external conditions change.

Phototropism is a plant's response to turn toward light. Gravitropism is a plant's response to grow upward against gravity.