BIO112 Lec4 Plant Reproduction and Development 1a 2025

Page 1: Anisogamy

  • Anisogamy: A form of sexual reproduction involving gametes that are different in size and/or motility.

  • Different Forms of Anisogamy:

    • A) Anisogamy of Motile Cells: Both types of gametes (male and female) are capable of movement, but exist in varying sizes.

    • B) Oogamy: Characterized by a large, non-motile egg cell, and a smaller motile sperm cell.

    • C) Anisogamy of Non-Motile Cells: Involves gametes that cannot move; for example, a large egg and smaller spermatia (non-motile sperm).

Page 2: Plant Reproduction

  • Title: Benjamin, Plant Reproduction and Development

  • Reference: Benjamin Cummings Tajamin Cumming

Page 3: Plant Classification

  • Glaucophyta (Glaucophyte Algae):

    • Group within Plantae.

  • Rhodophyta (Red Algae):

  • Green Algae:

    • Ulvophyceae (Ulvophytes):

    • Contains chloroplasts with chlorophyll a and b, and β-carotene.

  • Common Ancestors:

    • All green plants share a common ancestor that adapted to freshwater habitats and developed the ability to live on land.

  • Plant Groups:

    • Nonvascular Plants:

      • Hepaticophyta (Liverworts)

      • Bryophyta (Mosses)

      • Anthocerophyta (Hornworts)

    • Vascular Plants:

      • Seedless Plants:

        • Lycophyta (Club Mosses)

        • Psilotophyta (Whisk Ferns)

        • Pteridophyta (Ferns)

        • Equisetophyta (Horsetails)

      • Seed Plants:

        • Gymnosperms:

          • Ginkgophyta, Cycadophyta, Cupressophyta, Pinophyta, Gnetophyta

        • Angiosperms:

          • Ulvophyceae, Anthophyta (Angiosperms)

Page 4: Garlic Cloves

  • Garlic Cloves Composition:

    • Consist of scale leaves.

  • Asexual Reproduction Structures:

    • Corm: Underground storage stem.

    • Rhizomes: Horizontal underground stems.

    • Bulb: A storage organ often consisting of fleshy leaves.

    • Tubers: Additional storage organs for underground plants.

    • Stolons: Above-ground horizontal stems (runners).

Page 5: Alternation of Generations

  • Sea Lettuce (Ulva lactuca):

    • Demonstrates a haplodiplontic life cycle where both haploid and diploid stages are multicellular.

  • Animal Life Cycles:

    • Typically diplontic life cycles.

Page 6: Flower Diversity**

  • Flower Parts:

    • Carpel: Female reproductive structure.

    • Stamen: Male reproductive structure.

    • Petal: Attracts pollinators.

    • Sepal: Protects flower bud.

  • Angiosperms (Flowering Plants):

    • Show diverse floral structures with various arrangements of carpels, stamens, petals, and sepals.

Page 7: Reproductive Structures and Processes**

  • Sporangium: Produces spores.

    • Types include megasporangium and microspore production.

  • Haploid and Diploid Stages:

    • Female stages are haploid, and male stages can include diploid stages leading to megaspores from meiosis.

  • Pollen Development:

    • Pollen grain formation undergoes mitosis where usually only one survives while others degenerate.

  • Fertilization Process:

    • Pollen Tube Growth: The pollen tube is essential for delivering sperm to the ovule - fertilization occurs when one sperm fuses with the egg cell and another sperm with the polar nuclei in the ovule, leading to triploid tissue formation.