Connect! Do plants react to their environment? How? Give 2 examples. Give two examples of animals reacting to their environments. What is the process of adjusting the internal environment to external conditions called?

Plants Plants have hormones that are produced by cells which effect the growth and development of other cells Plants do not have specialized organs to make hormones. However, most hormone production is found in actively growing areas such as the tips of roots and stems, buds, and seeds.

These actively growing areas are called apical meristems.

These hormones are involved in growth, reproduction, and tropisms. Auxins are a type of plant hormone which influence division, elongation, and differentiation of plant cells. Stop and Think! What do the words division, elongation, and differentiation mean, in terms of plant cells?

 Unequal distribution of auxins causes unequal growth responses called tropisms  Unequal auxin distribution can be caused by external stimuli such as light and gravity

 Tropisms are adaptive growth responses that help the plant survive AUXIN S are on the DARK SIDE

Hormones promote other changes including flowering, fruit formation, and seed development…

Chunk! Where do plants produce hormones? What are these areas called?? Name a type of plant hormone. What is a tropism? Explain, in detail, why plants bend toward light. What other plant activities are plant hormones involved in?

Animals Differs from chemical control in plants since animals have endocrine glands which produce and secrete hormones

hormones are chemicals secreted in one area of the body which affect responses in other areas

the circulatory system carries these hormones from the endocrine glands to target organs

animals have many hormones that control activities such as reproduction and metamorphosis

Metamorphosis is controlled by hormones.

Chunk! How does chemical control differ in plants and animals? What are hormones? How do hormones move around in an animal? What is the cell or organ they aim at called? What do tadpoles and caterpillars have to do with hormones?