Plant Reproduction Study Notes

PLANT REPRODUCTION

Flowering Plants: Reproduction

• Types: Asexual and Sexual
• Key structures include: Reproductive Structures, Pollination, Seeds.

Reproductive Structures in Angiosperms

• Stigma: Sticky receptor for pollen.
• Carpel: Includes ovary that develops into fruit.
• Stamen: Composed of filament (supports anther) and anther (produces microspores/pollen).
• Sepal, Petal, Receptacle: Surround and protect reproductive structures.

Sexual Reproductive Strategies

• Microspore: Male gametophyte, forms pollen grains through mitosis.
• Megaspore: Female gametophyte, becomes an embryo sac within the ovule.
• Fertilization: Pollen grain germinates on stigma, leading to sperm formation and subsequent fusion with the egg and polar nuclei, resulting in endosperm development.

Alternation of Generations

• Sporophyte (2n): Multicellular, produces haploid spores via meiosis.
• Gametophyte (1n): Develops from haploid spores, produces gametes via mitosis.
• Zygote (2n): Forms from the fusion of gametes, develops into sporophyte.

Seed Structures

• Seed coat: Protective covering around the seed and endosperm.
• Cotyledon: Seed leaf that nourishes the embryo.

Seed Germination

• Epicotyl: Part between cotyledons for shoot development.
• Hypocotyl: Section below cotyledons contributing to stem.
• Radicle: Embryonic root that develops during germination.

Eudicot vs. Monocot Germination

• Eudicots: Two cotyledons; radicle and shoots develop above ground.
• Monocots: Single cotyledon; shoot formation protected by coleoptile, cotyledon remains below ground.

Learning Objectives

• Stages of a plant’s life cycle.
• Structure and function of male and female gametophytes.
• Explain seed production and double fertilization process.