1. Plants Chapter 8

2. Course of Study Objectives 7.) Describe biotic and abiotic factors in the environment. Examples: - biotic-plants, animals; - abiotic-climate, water, soil Classifying organisms as autotrophs or heterotrophs 5.) Identify major differences between plants and animals, including internal structures, external structures, methods of locomotion, methods of reproduction, and stages of development. Describing the processes of photosynthesis and cellular respiration

3. What is a Plant? Characteristics of plants: Autotrophs-they make their on food Eukaryotes- they have a true nucleus Their cells have a cell wall

4. Plant Adaptations Adaptations plants have made to survive on land include… Plants obtain water and nutrients from the soil. Plants retain water by using a waxy, waterproof layer that covers the plant’s leaves called a cuticle. Large plants transport water, minerals, and food through vascular tissues. Small plants transport water, food, and minerals between cells. Vascular tissues and cell walls help plants support themselves. Many plants have adapted to make fertilization occur in a dry environment.

5. Vascular and Nonvascular Plants Plants are divided into 2 groups Nonvascular plants- lack vascular tissues Vascular plants- contain vascular tissues

6. Complex Life Cycles Plants have 2 different stages in their life cycle.(p.255) Sporophyte stage- the plant produces spores (cells that grow into new organisms) Gametophyte stage- the plant produces sex cells

7. Plant Life Cycle p. 255 Retrieved 2/8/09 from http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio% 20102%20lectures/Seed%20Plants/seed_plant_life_cycle.gif

8. Nonvascular Plants The three groups of nonvascular plants include: Mosses Liverworts Hornworts These low growing plants live in moist areas so they can absorb water and nutrients from their environment.

9. Nonvascular Plants Liverworts Moss Hornworts

10. Seedless Vascular Tissue Seedless vascular plants have true vascular tissue and reproduce by spores. There are three types of seedless vascular plants: Ferns Club Mosses Horsetails

11. Seedless Vascular Tissue FernClub Moss Horsetail

12. Seed Plants All seed plants share two characteristics They contain vascular tissue They use pollen and seeds to reproduce

13. Vascular Tissue There are 2 types of vascular tissue Phloem-moves food down the plant Xylem- moves water and minerals up the plant

14. Seed Plants Seed plants reproduce using 2 unique adaptations… Pollen- a tiny structure that contains the cells that will become sperm. Seed-the structure that incases and protects the young fertilized embryo.

15. Seed Structures There are three main parts of a seed Embryo-the fertilized egg Stored food –used during development Cotyledon- embryonic leaf/leaves

16. Seed Dispersal Seeds are dispersed by 3 different ways By animal By water By wind

17. Germinations Seeds may lay dormant for a period of time before they start to grow/germinate. Germination- occurs when the embryo begins to grow again and pushes out of the seed.

18. Roots Roots anchor a plant in the ground, absorbs water and minerals from the soil, and sometimes stores food. There are two different types of root systems Fibrous root systems-dense, tangled mass of fibrous roots Taproot systems- one long, thick main root Fibrous roots Taproot

19. Stems Stems carry substances between the plant’s roots and its leaves. Stems provide support for the plant. There are two types of stems Herbaceous-soft stems with phloem and xylem. Woody-hard stems with several different layers of tissues.

20. Annual Rings Cambium- layer of cells which divide to produce new phloem and xylem. When new xylem is made, the old xylem becomes heart wood. Each layer of old xylem makes up a pattern called an annual ring.

21. Leaves Leaves capture the sun’s energy and carry out the food- making process of photosynthesis. Stomata-a small hole that popes open and close to control when gases enter and leave the leaf. Transpiration-the process by which water evaporates from a plants leaves. Stomata

22. Gymnosperms and Angiosperms There are two types of seed plants Gymnosperms- produce naked seeds Angiosperms- flowering plants that produce seed with fruits.

23. Gymnosperms Four types of gymnosperms exist Cycads Conifers Ginkgoes Gnekophytes

24. Reproduction of a Gymnosperm The egg develops in a structure called an ovule First, pollen falls from a male cone onto a female cone. In time, a sperm cell and an egg cell join together in an ovule on the female cone.

25. Reproduction of an Angiosperms All angiosperms use flowers for reproduction. Parts of a flower Sepals-small leaflike part of the plant Petals-colorful leaflike structures Stamen- male reproductive parts Pistil- female reproductive parts

26. Pollination Pollinators-small organisms that ensure that pollination occurs. First, pollen falls on a flower’s stigma. In time, the sperm cell and egg cell join together in the flower’s ovule. The zygote develops into the embryo part of the seed.

27. Monocots and Dicots Angiosperms are divided into two major groups Monocots-one embryonic leaf (cotyledon) Dicots-two embryonic leaves

28. Tropism Tropism-a plants growth response toward or away from a stimulus. Three important stimuli to which plants show tropism are Touch-ex. Vines growing around a wire Light- ex. Plants growing toward light Gravity- ex. A plan’st root’s growing down and stems growing up.

29. Hormones Plants respond to touch, light, and gravity because they produce hormones. Auxin is a major plant hormone that makes the plant grow in the presents of light.

30. Seasonal Changes What triggers a plant to flower? The amount of darkness a plant receives Short-day plants-flower when nights are longer than a critical length (bloom in fall or winter) Long-day plants- flower when nights are shorter than a critical length (bloom in spring or summer) Day-neutral plant- not sensitive to dark or light Dormancy-a period when a plant’s growth or activity stops.

31. Life Spans of Angiosperms Angiosperms are classified into annuals, biennials or perennials. Annuals- complete a life cycle within one growing year. Biennials- complete a life cycle within two years Perennials- complete a life cycle in more than two years