Unit 13 “Plants”

1. Unit 13“Plants”

2. Plant BasicsParts 1-2

3. Characteristics of All Plants • Multicellular • Eukaryotic • Cells surrounded by cell wall • Autotrophic (a producer) • Sessile • Reproduce sexually with egg and sperm

4. Plant Parts • Roots=root system • Roots- anchor plants, absorb water/nutrients, stores food • Stems and leaves=shoot system • Stems- transport materials from roots to leaves • Leaves- absorb sunlight, site of photosynthesis

5. Parts of a Leaf • Flat portion- blade • Leafstalk-petiole • Tip of the leaf- apex

6. Leaf Structure • Cuticle- waxy top layer than prevents water loss. • Epidermis- Protective covering on the top and bottom of the leaf. • Stomata- tiny openings in the lower epidermis of the leaf that allows gases to enter/leave the leaf. • Guard cells- crescent-shaped cells located on the sides of the stomata that contract to open/close the stomata. • Veins- run through the leaf in order to deliver water/nutrients. • Leaf cells contain many chloroplasts.

8. Types of Leaves • Simple • One blade per petiole • Compound • More than one blade per petiole. • The entire structure is the leaf.

9. Leaf Arrangement • Alternate • One blade per node in an alternating pattern. • Opposite • Two leaves grow from each node • Whorled • Three or more leaves grow from the node.

10. alternate whorled opposite whorled

11. Types of Leaf Venation • Parallel • Veins in each leaf extend from top to bottom. • Branched • The midvein branches into many numerous veins.

12. Parallel venation Branched venation

13. Shoot System • Above the ground • Made up of stems and leaves • Holds up leaves toward the sun • Manufactures food • Provides flowers, fruits, and seeds.

14. Root System • Typically underground • Made up of the roots • Anchors the plant • Absorbs water and nutrients from the soil.

15. Vascular System • Made of long tube-like cells • Extends from roots to leaves • Transports nutrients, water, and minerals. • Made of two tissues: 1. xylem- transports water and nutrients from roots; larger than phloem. 2. phloem- transports sugars from leaves to stems and roots

18. Types of Root Systems • Fibrous • Primary root remains small and has numerous, small hair-like roots extending from it. • Taproot • Primary root grows straight down and is larger than the secondary roots that extend from it. • Often store large amounts of food such as in carrots.

20. Seedless PlantsPart 3

21. Nonvascular Seedless Plants • No vascular tissue • Grow small • Do not produce seeds, produce spores instead. • No roots, stems, or leaves • Nutrients move from cell to cell • Example: mosses, hornworts, & liverworts

23. Seedless Vascular Plants • Have vascular tissue • Produce spores instead of seeds. • Grow larger than mosses • Have roots, stem, and leaves • Example: ferns, club mosses, horsetails

25. Unit 13 Notes, Part 4 Seed Plants Gymnosperms & Angiosperms

26. Seed Plants • Divided into two categories: • Angiosperms- “Flowering plants” • Gymnosperms- “Nonflowering plants”

27. Angiosperms • Plants that produce flowers and produce seeds inside fruit. • Sperm is located inside pollen grains. • Eggs develop into embryos • Flower-reproductive structure • Fruit-ripened ovary of an angiosperm, encloses the seed.

28. Monocots vs. Dicots • Angiosperms are divided into monocots and dicots • As the zygote grows into the embryo, the first leaves of the young plant develop and are called as cotyledons (seed leaves). • Monocots have one cotyledon (corn, lily, etc). • Dicots have two cotyledons (bean, oak, etc).

29. Comparing Monocots and Dicots

30. Summary: Monocots vs. Dicots

31. Flowers • Male & female parts on same OR separate flower. • Parts of a flower: • Sepals- leaf-like structures that enclose the flower before opening. • Petals- surround pistil, attract animals for pollination • Stamen- male part (produces sperm) • Pistil- female part (produces eggs) • Stigma = sticky tip of the pistil • Style = tube connecting stigma to ovary • Ovary = contains the eggs

32. The Structure of a Flower

33. Seeds • When plant eggs are fertilized with sperm, a seed forms. • Seeds contain a young, developing plant embryo. • Inside is stored food that the young plant uses as it begins to sprout or germinate.

34. Seed Structure Example:

35. Reproduction of Angiosperms: Pollination = Pollen falls on a stigma when wind, bees, or bats carry it. Fertilization = sperm & egg join together in the flower’s ovule (inside ovary), later forming seed. A fruit is formed around the seed. Dispersal – animals eat the fruit and the seeds come out the other end, where they will grow into mature plants that produce more seeds.

36. Gymnosperms • Means “naked” seed. • Seeds are not enclosed in fruits. • Do not produce flowers • Examples of gymnosperms: conifers (pine/cedar trees), cycads, ginkgo biloba trees, juniper

37. Conifers • Conifers are adapted to temperate to cold regions • Narrow leaves (needles) help to conserve water • Covered by resins – for protection from predators, fire, etc.

38. Reproduction of Gymnosperms Pollen is produced by male cones, and pollen are tiny cells that later become sperm cells. Ovule is a structure containing an egg cell. Pollination= transfer of pollen from male part to female part. (Pollen falls from a male cone to a female cone and fertilizes an ovule, which develops into a seed, with the zygote as the embryo part of the seed. It can take two years for seeds to mature, then the cones open & wind carries the seeds off.)