Chapter 10

1. Chapter 10 Plant Reproduction

2. Ch 10.1 – Intro to Plant Reproduction A. Plants can reproduce both sexually and asexually 1. In asexual reproduction a new plant can be grown from a leaf, stem or root

3. Grass Seeds (Sexual Repro.)

4. 2. In sexual reproduction a sperm cell fertilizes an egg cell to form a zygote a) Some plants have both male and female reproductive organs; these can reproduce by themselves or with sex cells from other plants of the same type b) Some plant species have male and female organs on separate plants

5. B. Plants have a 2 stage life cycle: 1. Gametophyte Stage – produces sex cells 2. Sporophyte Stage – produces spores

6. Ch 10.2 – Seedless Reproduction A. Seedless plants do not produce seeds 1. Spores of seedless plants grow into a plant that produces sex cells 2. All nonvascular and some vascular plants are seedless

7. B. Moss Plants have a life cycle that illustrates typical sexual reproduction in nonvascular seedless plants 1. The gametophyte stage produces sex cells which fuse and develop into a sporophyte 2. The sporophyte stage produces spores

8. 3. When spores are released and land in an appropriate environment they can grow into a new gametophyte plant 4. Nonvascular plants can also reproduce asexually if a piece of the gametophyte breaks off and lands in an appropriate environment

9. Moss Life Cycle

10. C. Most vascular seedless plants are Ferns 1. Sporophyte plants have leaves called fronds 2. Grow from underground stem called rhizome

11. 3. Spores are produced in spots on underside of fronds called sori 4. A spore that lands in a favorable location grows into the gametophyte stage which is called a prothallus

12. 5. The prothallus produces sex cells 6. When fertilization occurs, the zygote develops into the sporophyte stage

13. Fern Life Cycle

14. 7. Ferns may reproduce asexually when rhizomes form new brances and are separated from the main plant

15. Ch 10.3 – Seed Reproduction A. Pollen and seeds help many plants reproduce 1. Pollen grain – has a covering and contains gametophyte parts that produce sperm cells

16. 2. Pollination – occurs when pollen grains are transferred to the female part of the plant which allows fertilization to take place

17. 3. Following fertilization, the female part of the plant produces a seed which contains an embryo, stored food and a protective coat

18. 4. Plants can develop more quickly from a seed than from a spore because a seed contains an embryo and stored food

19. B. Gymnosperms – develop seeds in cones 1. A pine tree or shrub is a sporophyte plant that produces male and female cones

20. 2. Female coneshave two ovules which produce egg cells

21. Variation of Cones

22. California Redwoods

24. 3. Male cones produce and release pollen

25. 5. Seed release by a female cone can take 2 or 3 years

26. C. Angiosperms – produce flowers which are used in sexual reproduction and develop seeds inside of fruit

27. 1. Flower parts: a) Stamen – male reproductive organ; made of a thin stalk called the filament and top portion with pollen called anther

28. b) Pistil – female reproductive organ; contains stigma with sticky nectar at top, thin stalk called style in middle and ovary at base which contains 2 ovules each with an egg cell inside

29. Flower Anatomy

30. 2. The appearance of a plant’s flowers can give clues about how the plant is pollinated

31. 3. After pollination and fertilization a zygote forms and grows into the plant embryo 4. The ovule develops into the seed coat and store endosperm (food) for the embryo in cotyledons 5. Flower petals fall off and a fruit develops around the seed to aid in dispersal

32. D. Seeds are dispersed by wind, gravity, animals and water 1. Germination – occurs when seed coat swells and breaks open allowing the embryo to sprout and begin growing into a new plant