1. Plant Life Cycles -All plants alternate between two phases in their life cycles.

2. Alternation of generations Sporophyte (diploid) –B–Begins when sperm fertilizes egg (zygote) –D–Diploid zygote divides by mitosis to create a mature sporophyte –M–Meiosis produces haploid cells called spores –H–Haploid spores released

3. Gametophyte (haploid) –B–Begins with spores created by meiosis –S–Spore grows into gametophyte Male gametophyte creates sperms Female gametophyte creates eggs –S–Sperm & egg create diploid zygote (process repeats)

4. Group 1: Seedless, nonvascular plants ex: moss Nonvascular plants have a dominant gametophyte phase. – moss gametophytes look like green carpet – moss sporophytes shoot up as stalklike structures sporophyte (2n) gametophyte (1n) capsule spores (1n)

5. gametophyte 1) Moss gametophytes grow near the ground (haploid stage) 2) Through water, sperm from the male gametophyte will swim to the female gametophyte to create a diploid zygote 3) Diploid sporophyte will grow from the gametophyte where the zygote is located 4) Sporophyte will create and release haploid spores..... sporophyte

6. 5) Spores land and grow into new gametophytes..... groundgametophyte 6) The process repeats

7. Plant Life Cycle Comparisons Plant typeSporophyteGametophyteDominant? MossStalk with cup (capsule) at tip, which is where spores are produced. More familiar, carpet-like plant that produces specialized gametes GAMETOPHYTE FernMore familiar, leafy plant with clusters of spore producing sacs (sori) Haploid plant body (prothallus) is size of a finger nail, produces both male and female parts SPOROPHYTE ConiferMore familiar- like pine trees, produces male and female cones that produce spores Pollen grains are male gametophytes  sperm, female gameotphytes are microscopic  eggs SPOROPHYTE

8. Group 2: Seedless, Vascular Plants Ex: Ferns

9. Ferns Seedless, vascular plants –V–Vascular: allows taller growth Rhizoids: underground stems draw nutrients Fronds: leaves uncurl –s–sporangia on underside Sori: clusters of sporangia

10. Fern Life Cycle Sporophyte phase –D–Dominant stage –S–Sporangia produces haploid spores –S–Spores released into air Gametophyte phase –S–Spore grows into prothallus Archegonium: produces female egg Antheridium: produces male sperm –S–Sperm swims to egg –Z–Zygote begins sporophyte stage See appendix B in your text book

11. Adult Sporophyte (diploid).... 1) Sporophyte creates and releases haploid spores ground

12. 3) From the haploid spores, a prothallus (haploid gametophyte) grows in the soil -- Rhizoids anchor Let’s zoom in

13. 4) Sperm swim through water from the antheridium to the archegonia Let’s zoom back out

14. ground 5) Diploid sporophyte (fiddlehead) grows from the prothallus -- prothallus eventually dies

15. 6) Fiddlehead uncurls into fronds of ferns. ground 7) Cycle repeats -- Sporangia creates spores to be released....

16. Plant Life Cycle Comparisons Plant typeSporophyteGametophyteDominant? MossStalk with cup (capsule) at tip, which is where spores are produced. More familiar, carpet-like plant that produces specialized gametes GAMETOPHYTE FernMore familiar, leafy plant (fronds)with clusters of spore producing sacs (sori) Haploid plant body (prothallus) is size of a finger nail, produces both male and female parts SPOROPHYTE ConiferMore familiar- like pine trees, produces male and female cones that produce spores Pollen grains are male gametophytes  sperm, female gameotphytes are microscopic  eggs SPOROPHYTE

17. Group 3: Seed producing, Vascular Plants 1) Seed plants don’t depend on water to reproduce –P–Pollen (contains sperm) combines with egg –E–Egg hardens into a seed 2) Nourishment and protection –N–Nourish: Nutrients inside seed for the embryo –P–Protection: Hard shell 3) Allow dispersal –C–Carried by wind, water, animals

18. Type 1: Gymnosperms Seeds not enclosed in a fruit –p–produced inside cones Cone = reproductive structure Male cones: produce pollen Female cones: produce eggs and seeds

19. Gymnosperm example: Conifers –C–Cone plants –N–Needle-like leaves –C–Common to lumber industry –E–Evergreen, Pine, Redwood, Cedar

20. The sporophyte is the dominant phase for seed plants.

21. 1) Male and female seed cones grow in adult sporophytes

22. 2) Pollen grains released from the male seed cones -- Pollen is the male gametophyte Let’s zoom into the female seed cone

23. 3) Pollen grain sticks to the female ovule 5) Two nuclei transfer into female spore - one fertilizes the egg 4) Pollen tube grows from the male spore 6) Diploid embryo develops (sporophyte stage restarts)

24. 7) After seeds harden, the cone reopens and the seeds are released

25. 8) Seed will land ground

26. 9) Seedling grows into (sporophyte)…the cycle repeats ground

27. Plant Life Cycle Comparisons Plant typeSporophyteGametophyteDominant? MossStalk with cup (capsule) at tip, which is where spores are produced. More familiar, carpet-like plant that produces specialized gametes GAMETOPHYTE FernMore familiar, leafy plant with clusters of spore producing sacs (sori) Haploid plant body (prothallus) is size of a finger nail, produces both male and female parts SPOROPHYTE ConiferMore familiar- like pine trees, produces male and female cones that produce spores Pollen grains are male gametophytes  sperm, female gameotphytes are microscopic  eggs SPOROPHYTE

28. Angiosperm Life Cycle

29. Wind pollinated flowers- small flowers and large amounts of pollen. Animal pollinated flowers- larger flowers and less pollen (more efficient). Flowering plants are pollinated when pollen grains land on stigma

30. Fertilization takes place within the flower. Male gametophytes, or pollen grains, are produced in the anthers. –male spores produced in anthers by meiosis –each spore divides by mitosis to form two haploid cells= pollen grain pollen grain anther stamen

31. One female gametophyte can form in each ovule of a flower’s ovary. o Many cells can be made in the ovule one cell becomes the egg one cell becomes 2 polar nuclei the rest die Polar nuclei (2n)

32. 1.Pollen grains are released Wind or animals

35. 2. Pollen grains land on the stigma (pollination)

36. .. 3. Pollen tube grows and 2 sperm nuclei transfer into the ovule Let’s zoom in…

37. 4. Flowering plants go through the process of double fertilization. female gametophyte ovule egg sperm polar nuclei 1 sperm fuse with the polar nuclei = triploid (3n) endosperm 1 sperm fuse with the egg = zygote 22.2 Flower Life Cycle Double Fertilization

38. endosperm seed coat embryo Endosperm provides food supply for embryo 5. Each ovule becomes a seed. The surrounding ovary grows into a fruit. 22.2 Flower Life Cycle

39. 6. Seeds get dispersed 7. Seed germinates(sporophyte), and the cycle starts over ground

40. Plant Life Cycle Comparisons Plant typeSporophyteGametophyteDominant? MossStalk with cup (capsule) at tip, which is where spores are produced. More familiar, carpet-like plant that produces specialized gametes GAMETOPHYTE FernMore familiar, leafy plant with clusters of spore producing sacs (sori) Haploid plant body (prothallus) is size of a finger nail, produces both male and female parts SPOROPHYTE Conifer ( gymnosperm ) More familiar- like pine trees, produces male and female cones that produce spores Pollen grains are male gametophytes  sperm, female gameotphytes are microscopic  eggs SPOROPHYTE Flower ( angiosperm ) More familiar- apple tree, peach tree, zucchini, berries, etc. Contain flowers that produce male and female spores Pollen grains are male gametophytes  2 haploid cells = pollen tube + sperm, Female gametophyte in ovule  egg + 2 polar nuclei SPOROPHYTE 22.2 Flower Life Cycle