1. 1.What are the main parts of this tree? 2.What is the function of each part?

2. REVIEW How do plants obtain energy? In the food chain, they are the producer….

3. PLANT STRUCTURE AND FUNCTION Roots: Anchors the plant Collects water and nutrients for plant Cannot carry out photo. ROOTS Stem: Above ground Transports nutrients If green, can photosynthesize STEM Leaves: LEAVES Major Photosynthesis Transpiration Remember Capillary Action and Adhesion

4. ROOTS Roots can be short or long Roots can be thick and massive or thin and thread-like. Most roots grow in the soil, some do not…. Rhizome

5. TYPES OF ROOTS 1. TAPROOTS: like carrots and beets single thick structures with smaller branching roots accumulate and store food

6. TYPES OF ROOTS 2. Fibrous Roots: have many small branching roots from a central point example: grass

7. TYPES OF ROOTS 3. PROP ROOTS: originate above ground to help support the plant example: corn

8. Section 23.3 Summary – pages 622-625 Plant Hormones Plants, like animals, have hormones that regulate growth, help them respond to the environment, and send chemical messengers. A hormone is a chemical that is produced in one part of an organism and transported to another part, where it causes a physiological change. The plant’s hormones are produced in the ROOTS.

9. STEMS Stems transport water, dissolved minerals, and sugar to and from roots and leaves. 1. Herbaceous Stems 2. Woody stems Fleshy, green stems, Can also carry out photosynthesis. Grow year after year Have cork tissue for protection

10. Section 23.2 Summary – pages 612-621 These annual growth rings can be used to estimate the age of the plant. Annual growth rings Xylem Vascular cambium Phloem Cork Woody stems are composed primarily of dead xylem cells. A tree trunk is one example of a woody stem.

11. Besides age, the thickness of a tree can show how much water was available at the time. A thin tree ring indicates a year of drought.

12. LEAVES Cuticle Upper epidermis Palisade Layer (where most chloroplasts are found) The primary function of the leaves is photosynthesis. Sunlight passes through the transparent cuticle into the photosynthetic tissues just beneath the leaf surface.

13. LEAVES Size, Shape, and type of leaves vary enormously. Opposite Arrangement

14. Section 23.2 Summary – pages 612-621 Gases can also move in and out of a leaf through the stomata, which are located in the upper and/or lower epidermis. LEAVES Stomata

15. Section 23.2 Summary – pages 612-621 Guard cells are tiny cells that surround and control the size of a stoma. LEAVES The loss of water through the stomata is called transpiration.

16. Section 23.2 Summary – pages 612-621 Transpiration When water enters the guard cells, the pressure causes them to bow out, opening the stoma. Stoma Guard cell Water LEAVES

17. Section 23.2 Summary – pages 612-621 Transpiration As water leaves the guard cells, the pressure is released and the cells come together, closing the stoma. Water LEAVES

18. Section 23.2 Summary – pages 612-621 One way to distinguish among different groups of plants is to examine the pattern of veins in their leaves. LEAVES PARALLEL VEINS (Monocot) NET-LIKE VEINS (Dicot)

19. Section 23.3 Summary – pages 622-625 Although a plant lacks a nervous system and usually cannot make quick responses to stimuli, it does have mechanisms that enable it to respond to its environment. Plants can respond to: Gravity Light Temperature PLANT RESPONSES

20. Section 23.3 Summary – pages 622-625 Tropism is a plant’s response to an external stimulus. The tropism is called negative if the plant grows away from the stimulus. The tropism is called positive if the plant grows toward the stimulus. PLANT RESPONSES WE WILL LOOK AT THREE TYPES OF TROPISM

21. Section 23.3 Summary – pages 622-625 As these cells lengthen, the stem bends toward the light. The growth of a plant toward light is called phototropism. TROPISM

22. Section 23.3 Summary – pages 622-625 Gravitropism is plant growth in response to gravity. Roots that grow down into the soil are able to anchor the plant and can take in water and dissolved minerals. TROPISM Stems usually exhibit a negative gravitropism. How do growing seeds exhibit both phototropism and gravitropism?

23. Section 23.3 Summary – pages 622-625 Some plants exhibit another tropism called thigmotropism, which is a growth response to touch. Because tropisms involve growth, they are not reversible. The position of a stem that has grown several inches in a particular direction cannot be changed. TROPISM Ivy is a good example of a plant that exhibits all three types of tropism.

24. Section 23.3 Summary – pages 622-625 A responsive movement of a plant that is not dependent on the direction of the stimulus is called a nastic movement. An example of a nastic response is the sudden closing of the hinged leaf of a Venus’s-flytrap. PLANT RESPONSES Naustic movements do not involve growth.

25. Section 24.2 Summary – pages 641-645 The relative lengths of daylight and darkness each day have a significant effect on the rate of growth and the timing of flower production in many species of flowering plants. The response of flowering plants to daily daylight- darkness conditions is called photoperiodism.

27. Section 1 Check Question 1 Most plants produce their own food in the form of _______. D. chlorophyll C. glucose B. proteins A. cellulose The answer is C.

28. Section 1 Check Question 2 Which of the following is NOT a function of most plant roots? D. anchoring the plant C. store starch B. conducting photosynthesis A. absorbing water and nutrients The answer is B.

29. Section 2 Check Most roots that humans eat are _____ roots. Question 3 D. aerial roots C. prop roots B. fibrous roots A. taproots The answer is A, taproots.

30. Chapter Assessment Question 4 If a plant becomes too dry, are the stomata in the leaves more likely to be open or closed? Answer The stomata are more likely to be closed to prevent any more water loss from the plant.

31. Chapter Assessment Question 5 What is the main difference between tropisms and nastic responses? Answer The main difference between the two is that tropisms are not reversible and nastic responses are reversible. Also, nastic responses do not depend on the direction of the stimulus, tropisms do.

32. As you walk through a room, you notice that a plant sitting on a table 2 m from a window is leaning toward the window. What type of response is the plant exhibiting? Question 6 phototropism. Answer

33. Chapter Assessment Question 7 Name the two stages of a plant’s life cycle, and describe which each entails. Answer Gametophyte: Haploid stage Sporophyte: Diploid stage