CONTROL SYSTEMS

abscisic acid

plant hormone that regulates survival functions of a plant, such as the opening and closing of stomata

auxin

growth chemicals (hormones) produced in plants that are characterized by their ability to induce cell elongation and cell division in stems

cytokinins

growth chemicals (hormones) that help plant cells divide

ethylene

gaseous plant hormone that promotes ripening of fruit or blooming of flowers

geotropism

the movement or growth of a plant in response to gravity

gibberellin

growth chemicals (hormones) made by plants that stimulate stem elongation, seed germination, and flowering

homeostasis

the relatively constant state in the internal environment of an organism

hydrotropism

the growth of plants toward water

phototropism

the growth of a plant in response to sunlight

thigmotropism

the movement or growth of a plant in response to touch

tropism

plant growth caused by external stimulus

............. is the process by which internal environments of an organism are regulated.

Homeostasis

Plant growth caused by external stimulus is _____.

a tropism

How do plants maintain homeostasis? Select all that apply.

By exchanging gas through stomata.
By closing stomata to prevent water loss.
By altering the activity within a cell with chemical transmitters.
By growing towards sunlight.

The chemical that promotes phototropism is _____.

Auxin

If you want your crops to grow larger than they normally would, you may want to try adding _____.

gibberellin

_____ helps plant cells divide and is located primarily in roots and fruits.

Cytokinin

This is a plant hormone that is given off to ripen fruit or flowers.

Ethylene

Leaves curving towards sunlight are examples of _____.

phototrophism

Roots growing down into the ground are examples of _____.

geotrophism

Plants growing towards air that has higher humidity levels are examples of _____.

hydortophism