* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download 22.5 Plant Hormones and Responses TEKS 10B
Survey
Document related concepts
Arabidopsis thaliana wikipedia , lookup
Plant tolerance to herbivory wikipedia , lookup
Ornamental bulbous plant wikipedia , lookup
Historia Plantarum (Theophrastus) wikipedia , lookup
Cultivated plant taxonomy wikipedia , lookup
History of botany wikipedia , lookup
Plant stress measurement wikipedia , lookup
Venus flytrap wikipedia , lookup
Plant use of endophytic fungi in defense wikipedia , lookup
Plant defense against herbivory wikipedia , lookup
Plant secondary metabolism wikipedia , lookup
Plant morphology wikipedia , lookup
Plant physiology wikipedia , lookup
Transcript
22.5 Plant Hormones and Responses The student is expected to: 10B describe the interactions that occur among systems that perform the functions of transport, reproduction, and response in plants TEKS 10B 22.5 Plant Hormones and Responses TEKS 10B KEY CONCEPT Plant hormones guide plant growth and development. 22.5 Plant Hormones and Responses ! Plant hormones regulate plant functions. • Hormones are chemical messengers. – produced in one part of an organism – stimulates or suppresses activity in another part TEKS 10B 22.5 Plant Hormones and Responses TEKS 10B • Gibberellins are plant hormones that produce dramatic increases in size. – ending seed dormancy – rapid growth of young seedlings – rapid growth of some flower stalks 22.5 Plant Hormones and Responses • Ethylene causes the ripening of fruits. – some fruits picked before they are ripe – sprayed with ethylene to ripen when reach destination TEKS 10B 22.5 Plant Hormones and Responses • Cytokinins stimulate cytokinesis. – final stage in cell division – produced in growing roots, seeds, and fruits – involved in growth of side branches TEKS 10B 22.5 Plant Hormones and Responses • Auxins lengthen plant cells in the growing tip. – stimulates growth of primary stem – controls some forms of tropism • A tropism is the movement of plant in response to an environmental stimulus. TEKS 10B 22.5 Plant Hormones and Responses TEKS 10B ! Plants can respond to light, touch, gravity, and seasonal changes. • Phototropism is the tendency of a plant to grow toward light. – auxins build up on shaded side of stem – cells on shaded side lengthen – causes stem to bend toward light 22.5 Plant Hormones and Responses TEKS 10B • Thigmotropism is a plant’s response to touchlike stimuli. – climbing plants and vines – plants that grow in direction of constant wind 22.5 Plant Hormones and Responses TEKS 10B • Gravitropism is a plant’s response to Earth’s gravitational pull. – positive gravitropism is downward growth (roots) – negative gravitropism is upward growth (shoots) 22.5 Plant Hormones and Responses TEKS 10B • Some plants have rapid responses not involving growth. – Some responses protect plants from predators. – Some responses allow plants to capture food. 22.5 Plant Hormones and Responses TEKS 10B • Photoperiodism is a response to the changing lengths of day and night. – triggers some plants to flower – triggers fall colors/winter dormancy of deciduous trees