Plants

1. Plants Chapters 22-25

2. What is a Plant? • Eukaryotic organism • Multicellular • Autotrophic

3. Chloroplast • Plants have chloroplast that carry out Photosynthesis • Photosynthesis (uses sunlight as energy sourche): CO2 + H20 -> Glucose (C6H12O6) and O2 • Chloroplast are green pigment that reflects green light • Has internal membrane that increases surface area • What is the advantage to Photosynthesis/Autotroph: • Can make own food don’t need to hunt of find

4. Plant cells have cell walls to add rigidity and protect the cell • The cell walls are made of cellulose which we cannot digest • Cellulose is a Carbohydrate

5. Plant types • Mosses • They lack a vascular system and true roots • Low growing plants that like to live near a water supply • These evolved fists- why they are most primitive

6. Ferns • Have roots and a vascular system • Do not have seeds

7. Roots • The usually underground portion of a plant that lacks leaves • serves as support • draws minerals and water from the surrounding soil • sometimes stores food • Root hairs- provide increase surface area • Roots are specialized for Mitosis why?

8. What is vascular tissue? • Tissue in the plant that transports water and nutrients • Xylem – transports water • Phloem – transports nutrients • Transpiration – water flows through the plant from root to leaf • Released onto leaf undersurface through stomata and evaporates

9. How are roots and vascular tissue an adaptation: allow plant to live in more arid conditions Grow to taller heights because can move water and nutrient by means other then diffusion

12. Gymnosperms • Cone bearers • Seeds are exposed • Called evergreens or conifers • Remain green all year- why is this an advantage? • Can perform photosynthesis all year

13. Seeds • A fertilized plant ovule containing an embryo. • Why is this an adaptation: sexual reproduction -> increased genetic variation

14. Germination • Process by which plants emerge from seeds and begin growth • Can lay dormant for long periods and wait on proper conditions • Temperature • Water • Why is this advantageous? • Best chance for survival

15. Pine Needles • The long, slender shape reduces leaf area, which, in turn, reduces the amount of water vapor escaping the leaf. (one time less surface are is an adaptation) • Pine needles are shed year round – just not all at one time.

16. Angiosperms • Flowering plants • Seeds protected by a layer of tissue • Flowers are the reproductive organs • Ovaries surround and protect seed inside the flower • Many times the ovaries will develop into fruit

17. Flowers • known as a bloom or blossom • is the reproductive structure found in flowering plants • The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs. • Increased by pollinators

19. Pollinators are attracted to flowers because of bright colors and they smell nice (same reason we like them) • Spreads pollen (sperm) to other flowers increasing genetic variation

20. Plant Reproduction • Mostly sexual reproduction • Some plants have a way of carrying out asexual reproduction

21. Pollen is the male gametes of plants • Can be compared to sperm cells in animals • Plants have ovules with eggs cells that can be fertilized by pollen • The seed is an early embryo that can, in some cases remain dormant for long periods of time

22. Covered seeds • The seed coat protects the seed • The endosperm (food supply) nourishes the embryo

23. Seed protection • Less likely to be eaten • Protected from environment • Nourishment for seed - better chance for survival

24. Seed dispersal • Seeds have different shapes or protective coverings to aid in their dispersal • Adaptation: move away from parent plant or other seedlings – less competition

25. Leaves • Wide broad leaves provide additional surface area to absorb sunlight • Increase photosynthesis • However increase rate of water loss which could be bad- so how do plants over come this

26. Adaptation to avoid water loss • Cuticle: waxy covering on leaves (lipids – hydrophobic) – keep water from entering or leaving • Stomata: openings in the bottom of the leaf that allow water to exit • Has guard cells on both sides of stomata to open and close

28. Specialized leaves for habitat Water lilies: thick cuticle to keep water out Cacti Needles: same as pine needles- reduce surface area (water loss) – also provide protection Broad leaves- for areas of limited sunlight (rainforest floor)

29. Can Plants Move? • Plants cannot get up and walk like us, but they can move stems and leaves toward certain stimuli • These movements are called tropisms

30. Gravitropism • Plant grows upward against the pull of gravity • Allows seed to grow up out of soil • Adaptation: to get sunlight

31. Phototropism • Plant grows toward light source • To get sunlight for photosynthesis

32. Thigmotropism • A plant’s response to touch • Can be used as protection • Can be used for stability • Venus fly trap uses to obtain food(nutrients)

33. Plant Hormones • Important for growth and maturation • Are chemical substances that control a plant’s patterns of growth and development • Example: Auxin’s role in phototropism

34. Auxin stimulates the elongation of cells • When light hits the tip of a plant, more auxin is produced in the shaded area • The dark side of the stem elongates causing the stem to bend toward the light

36. Uses of plants • Plants are a major food source for heterotrophs • Where do plants get their energy? • They are autotrophic and photosynthetic • Photosynthesis produces Oxygen

37. Other uses • Oils • Medicine • Lumber • Aesthetics • Shelter for animals • Commercial products