1 / 29

Plants & Life Cycles

Plants & Life Cycles. Chapter 12. Major groups of “ plants ”. Blue-green bacteria Algae Fungi Mosses Ferns and allies Gymnosperms Angiosperms. Generalized Plant Life Cycle. SPOROPHYTE 2N. spore mother cells. zygote (2N). diploid generation. FERTILIZATION. MEIOSIS.

channing-padilla
Download Presentation

Plants & Life Cycles

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Plants & Life Cycles Chapter 12

  2. Major groups of “plants” • Blue-green bacteria • Algae • Fungi • Mosses • Ferns and allies • Gymnosperms • Angiosperms

  3. Generalized Plant Life Cycle SPOROPHYTE 2N spore mother cells zygote (2N) diploid generation FERTILIZATION MEIOSIS haploid generation sperm spore antheridium egg GAMETOPHYTE N archegonium

  4. Life Cycle of a Flowering Plant

  5. Homospory and Heterospory Homospory • All spore are the same, with regard to size and “gender” • Each is capable of make a hermaphroditic, male or female gametophyte Heterospory • The spore are different in size and gender • Microspore = small, male • Megaspore = large, female • Each spore makes a specific gendered gametophyte

  6. Homosporous or Heterosporous?

  7. Homosporous or Heterosporous?

  8. Homosporous or Heterosporous?

  9. Homosporous or Heterosporous?

  10. Homosporous or Heterosporous?

  11. Homosporous or Heterosporous?

  12. Homosporous or Heterosporous?

  13. Summary of spore types in free-sporing and seed plants • Bryophytes: Mosses & Liverworts • Homosporous • Ferns and allies • Homosporous & Heterosporous • Seed Plants: gymnosperms & angiosperms • heterosporous

  14. Generalized Plant Life Cycle SPOROPHYTE 2N cell division & growth Specialized diploid reproductive cells (spore mother cells) zygote (2N) diploid generation MEIOSIS FERTILIZATION haploid generation Gametes (egg & sperm) spores cell division & growth GAMETOPHYTE (male or female) N

  15. 1. What do the terms haploid and diploid refer to? • Cell number • Eye number • Number of chromosomes • Number of chromosome sets • Number of nuclei

  16. 2. A life cycle illustrates the reproductive stages for an organism. What process causes the haploid stage to become diploid? • meiosis • mitosis • fertilization • sterilization • germination

  17. 3. What process causes the diploid stage to become haploid? • meiosis • mitosis • fertilization • sterilization • germination

  18. 1. Zygotic Life Cycle Zygote is the only diploid portion of the sporophyte generation Presumably the “original” life cycle zygote (2N) MEIOSIS FERTILIZATION Gametophyte (plant may act as gametes)

  19. 2. Gametic Life Cycle Gametes are the only haploid portion of the gametophyte Zygote grows mitotically SPOROPHYTE 2N cell division & growth Specialized diploid reproductive cells zygote (2N) FERTILIZATION MEIOSIS Gametes (egg or sperm)

  20. 3. Sporic Life Cycle Both generations (N and 2N) mitotic divisions Alternation of generations (sporophyte & gametophyte) SPOROPHYTE 2N cell division & growth Specialized diploid reproductive cells (spore mother cells) zygote (2N) MEIOSIS FERTILIZATION Gametes (egg or sperm) spores cell division & growth GAMETOPHYTE (male or female) N

  21. 4. What type of life cycle do most animals have (including humans)? • zygotic • gametic • sporic

  22. Vascular tissue Earth Forms Prokaryotic Cells Eukaryotic Cells Multicellular Plants Flowers 5,000 mya 4,000 mya 3,000 mya 2,000 mya 1,000 mya Seeds Major Evolutionary Advances • Life - 3,800 mya • Prokaryotic cell/autotrophic Place on the time scale, the following events: 1. Earth formation 2. Prokaryotes 3. Eukaryotes 4. Multicellular life 5. Vascular tissue 6. Seeds 7. Flowers • Flowers - 140 mya • Eukaryotic cell - 1,400 mya • Multicellar plants - 1,000 mya • Vascular tissue - 430 mya • Needed on land - why? • Seeds - 350 mya

More Related