UNIT 16: PLANTS Chapters 20-22 L.14.7

1. UNIT 16: PLANTS • Chapters 20-22 • L.14.7

2. KEY CONCEPTPlant life began in the water and became adapted to land.

3. Land plants evolved from green algae. • Plants and green algae have many common traits. • both are photosynthetic eukaryotes • both have the same types of chlorophyll • both use starch as a storage product • both have cell walls with cellulose

4. Genetic analysis points to the common ancestor of all plants. • extinct green algae species • modern species are still common in lakes and ponds

5. Important plant characteristics likely originated in algae • multicellular body allowing for specialization of cells and tissues

6. True plants evolved through natural selection. • Ancestral algae lived in areas of shallow water. • Those that could survive longer dry periods were favored. • First true plants probably grew at edges of water. • True plants have embryos that develop while attached to female parent. (seeds!)

7. True plants evolved through natural selection.

8. Challenges of living on land have selected for certain plant adaptations. A cuticle allows plants to retain moisture. waxy, waterproof layer Plants have adaptations that allow them to live on land. • holds moisture in

9. Stomata are tiny holes in the cuticle. stoma • can open and close • allow air to move in and out

10. A vascular system allows resources to move to different parts of the plant. water and mineral nutrients sugars • specialized tissues • brings water and mineral nutrients up from roots • disperses sugars from the leaves • allows plants to grow higher off the ground

11. Lignin allows plants to grow upright. lignin plant cells • hardens cell walls of some vascular tissues • provides stiffness to stems

12. Pollen grains allow for reproduction without free-standing water. • pollen grains contain a cell that divides to form sperm • pollen can be carried by wind or animals to female structures

13. A seed is a storage device for a plant embryo. • seed coats protect embryos from drying wind and sunlight • embryo develops when environment is favorable • (moisture, temperature, etc just right)

14. 21.1: Plant Cells & Tissues KEY CONCEPTPlants have specialized cells and tissue systems.

15. Dermal tissue covers the outside of a plant. protects the plant secretes cuticle of leaves forms outer bark of trees 21.1: Plant Cells & Tissues Plant organs are made of three tissue systems.

16. provides support stores materials in roots and stems 21.1: Plant Cells & Tissues • Ground tissue is found inside a plant.

17. two networks of hollow tubes xylem transports water and minerals UP from the roots to the rest of the plant phloem transports photosynthetic products DOWN from the leaves to the stems & roots stem leaf root 21.1: Plant Cells & Tissues • Vascular tissue transports water, minerals and organic compounds.

18. 21.2: The Vascular System KEY CONCEPTThe vascular system allows for the transport of water, minerals, and sugars.

19. water vapor exits leaf stomata helps pull water to the top branches 21.2: The Vascular System • Transpiration is the loss of water vapor through leaves.

20. 21.3: Roots & Stems KEY CONCEPTRoots and stems form the support system of vascular plants.

21. Roots provide many functions. support the plant absorb, transport, and store nutrients 21.3: Roots & Stems Roots anchor plants and absorb mineral nutrients from soil.

22. Stems have many functions. support leaves and flowers house most of the vascular system store water Baobab trees Cactus 21.3: Roots & Stems Stems support plants, transport materials, and provide storage.

23. grow underground for storage Ginger rhizomes Potato tubers 21.3: Roots & Stems Stems support plants, transport materials, and provide storage. • Stems have many functions. • support leaves and flowers • house most of the vascular system • store water

24. grow underground for storage Strawberry stolons 21.3: Roots & Stems Stems support plants, transport materials, and provide storage. • Stems have many functions. • support leaves and flowers • house most of the vascular system • store water • form new plants

25. Some stems are herbaceous and conduct photosynthesis. 21.3: Roots & Stems

26. Some stems can be woody, and form protective bark.

27. 21.4: Leaves KEY CONCEPTLeaves absorb light and carry out photosynthesis.

28. Stomata open and close when guard cells change shape. When stomata are open, water evaporates and gas exchanges. Stomata close at night and when plant loses too much water. stoma guard cells 21.4: Leaves • Guard cells surround each stoma.

29. READ BUT DON’T COPY Leaves may be simple, compound, or double compound. Compound leaf Simple leaf Double compound leaf

30. READ BUT DON’T COPY Leaf veins may be parallel or pinnate. Parallel veins Pinnate veins 21.4: Leaves

31. READ BUT DON’T COPY Leaf margins may be toothed, entire, or lobed. Toothed margin Entire margin Lobed margin 21.4: Leaves

32. 21.4: Leaves • READ BUT DON’T COPY • Leaves have many adaptations. • for extreme temperatures, ex: pine needles

33. 21.4: Leaves • READ BUT DON’T COPY • Leaves have many adaptations. • for extreme temperatures, ex: pine needles • for water loss,ex: cactus spines

34. for aquatic environments, ex: water lily 21.4: Leaves • Leaves have many adaptations. • for extreme temperatures, ex: pine needles • for water loss,ex: cactus spines • for getting food,ex: Venus’ flytrap

35. 22.2: Reproduction in Plants KEY CONCEPTReproduction of flowering plants takes place within flowers.

36. Sepals and petals are modified leaves. Sepals are outermostlayer that protectsdeveloping flower sepal 22.2: Reproduction in Plants Flowers contain reproductive organs protected by specialized leaves.

37. stamen filament anther 22.2: Reproduction in Plants • A stamen is the male structure of the flower. • produces pollen grains

38. stigma style carpel ovary 22.2: Reproduction in Plants • The innermost layer of a flower is the female part (carpel). • ovary produces female gametophyte (“egg”)

39. Flowering plants pollinated when pollen grains land on stigma. Wind pollinated flowers have small flowers and large amounts of pollen. 22.2: Reproduction in Plants Flowering plants can be pollinated by wind or animals.

40. Pollination occurs when a pollen grain lands on a stigma. pollen tube sperm stigma 22.2: Reproduction in Plants • one cell from pollen grain forms pollen tube • other cell forms two sperm that travel down tube

41. endosperm seed coat embryo • Flowering plants go through the process of double fertilization. • one sperm fertilizes the egg • other sperm unites with polar nuclei, forming endosperm • endosperm provides food supply for embryo

42. Each ovule becomes a seed. 22.2: Reproduction in Plants • The surrounding ovary grows into a fruit.