Plants

1. Plants • How do plants obtain nutrients? Through photosynthesis (process that converts energy from sunlight into sugars

2. Plants are autotrophs which means they make their own food by photosynthesis. • During photosynthesis, plants use carbon dioxide gas and water to make food and oxygen. http://grapevine.net.au/~grunwald/une/KLAs/science/irrigation-photosynthesis.gif

3. 6CO2 + 6H2O C6H12O6 + 6O2 • How do you read this equation in words? • What are the reactants? • What are the products? Six carbon dioxide molecules plus 6 water molecules yields 1 molecule of glucose and 6 water molecules 6CO2 and 6H2O (carbon dioxide and water) C6H12O6 and 6O2 (glucose and oxygen)

4. Plant Cells and Photosynthesis • In what organelle does photosynthesis occur? • What are other organelles that plants have that are not found in animal cells? Chloroplast

5. The cell wall is a boundary that surrounds the cell membrane and separates the cell from its environment. • The cell wall is made mostly of cellulose • Chloroplasts are the structures where photosynthesis takes place.

6. A vacuole is a large storage area that contains water, wastes and food. • The vacuole expands when water enters and shrinks when water leaves. http://www.biology4kids.com/files/art/cell_vacuole1.jpg

7. Plant Structures • Plants need adaptations to reduce water loss to the air. • One adaptation is a waxy, waterproof layer called the cuticle that covers the leaves of most plants • Tiny openings or pores found mostly on the underside of a plant leaf used for gas exchange are called stomata. Stomata

8. Epidermis is the single cell layer covering a plant (especially the leaf). • Veins are used to transport food and water throughout the leaf.

9. Plant Life Cycles • Plants have complex life cycles that are made up of 2 different stages or generations. • In one stage, called sporophyte, the plant produces spores (tiny cells that can grow into new organisms) • A spore develops into the next stage called a gametophyte. • In this stage, the plant produces gametes (egg and sperm cells) • The egg and sperm cell join to form a zygote.

10. Which components of this plant life cycle are sexual? Asexual?

11. Mosses • Nonvascular Plants are low growing plants that lack vascular tissue. • Other nonvacular plants are liverworts and hornworts. Liverwort Moss Hornwort

12. Moss Life Cycle

13. Ferns • Vascular plants are those that have vascular tissue which transports water throughout the plant. Spores on underside of fern leaf.

14. Fern Life Cycle

15. Compare the moss and fern life cycles. Moss Life Cycle Fern Life Cycle

16. Gymnosperms • Gymnosperms are plants that produce “naked” seeds. • Seeds are not enclosed in a protective covering. • Many gymnosperms also have needle-like or scale-like leaves and deep growing root systems.

17. Gymnosperm Reproduction • Most gymnosperms have reproductive structures called cones. • Many plants produce both male and female cones • Male cones produce tiny grains of pollen. • Pollen contains the microscopic cells that will later become sperm cells. • Female cones contain one ovule at the base. • The ovule is the structure that contains an egg cell.

18. Life Cycle of Gymnosperms • Pollen falls from male cone onto a female cone. • In time, a sperm cell and egg cell join together in an ovule on the female cone. • After fertilization occurs, the zygote develops into the embryo part of the seed.

19. Angiosperms • Angiosperms are plants that produce seeds enclosed in a fruit. • 2 characteristics of angiosperms: • Produce flowers • Produce fruits • The seeds develop in the ovary and the ovary is located in the flower.

20. Structure of Flowers • All flowers are used for reproduction. • Petals- the colorful structures you see when the flower opens. • When the flower is still a bud, it is enclosed by leaf-like structures called sepals.

21. Within the petals are the flower’s male and female reproductive parts. • Thin stalks topped by small knobs are called stamens (male reproductive parts) • Pistils (female reproductive parts) are usually found in the center of the flower.

22. Reproduction of Angiosperms • Pollen falls on stigma. • In time, sperm cell and egg cell join together in the flower’s ovule. • The zygote develops into the embryo part of the seed.

23. Some key terminology: • Pollination: transfer of pollen from male reproductive structures to female reproductive structures. • Fertilization: joining of egg and sperm cells. • Germination: the early growth stage of the embryo plant in a seed.

24. Where do you see pollination, fertilization and germination?

25. Think back: What is the difference between sexual and asexual reproduction? Sexual reproduction involves the joining of egg and sperm cells Asexual reproduction involves only one parent; no joining of egg and sperm cells

26. Asexual & Sexual Reproduction in Plants • Asexual: growing new plants by using cuttings • Sexual: pollination • What are some common types of pollination?

27. Seeds • Seeds are the result of sexual reproduction. • Seeds are structures that contain a young plant inside of a protective covering.

28. Spores • Spores are tiny cells that are capable of growing into a new organism. • Ferns release spores into their surroundings where they grow into gametophytes. http://upload.wikimedia.org/wikipedia/commons/8/8a/Fern_spores_P1180804.jpg