Biology: Flowering Plant Reproduction

Sexually Reproduction in Flowering Plants

Overview

• Sexually reproduction in flowering plants involves the production of gametes (sperm and egg cells) and the fusion of gametes to form a zygote.
• This process ensures genetic diversity and increases the chances of survival for the offspring.

Structure of a Flower

• A flower consists of four main parts:
  1. Petals: colorful structures that attract pollinators
  2. Sepals: green structures that protect the flower bud
  3. Stamen: male reproductive organs consisting of:
     • Anther: produces pollen grains
     • Filament: supports the anther
  4. Carpel: female reproductive organ consisting of:
     • Stigma: receptive surface for pollen
     • Style: narrow tube connecting stigma to ovary
     • Ovary: contains ovules (egg cells)

Pollination

• Pollination: the transfer of pollen from the anther to the stigma
• Agents of pollination: bees, butterflies, moths, birds, bats, and wind
• Types of pollination:
  • Self-pollination: pollen from the same plant or flower
  • Cross-pollination: pollen from a different plant or flower

Fertilization

• Fertilization: the fusion of a sperm cell with an egg cell
• Double fertilization: a unique process in flowering plants where:
  1. One sperm cell fuses with the egg cell to form a zygote
  2. Another sperm cell fuses with the polar nuclei to form the endosperm

Development of the Seed

• Seed: a mature ovule containing a zygote and endosperm
• Embryo: the developing plant within the seed
• Endosperm: a nutrient-rich tissue that nourishes the embryo

Development of the Fruit

• Fruit: a mature ovary that contains one or more seeds
• Types of fruits: simple, aggregate, and composite fruits
• Functions of fruits: protection, dispersal, and nutrition for the developing seed

Sexually Reproduction in Flowering Plants

• Sexually reproduction in flowering plants produces gametes (sperm and egg cells) and fuses them to form a zygote, ensuring genetic diversity and increasing offspring survival.

Structure of a Flower

• A flower consists of four main parts: petals, sepals, stamen, and carpel.
• Petals are colorful structures that attract pollinators.
• Sepals are green structures that protect the flower bud.
• Stamen are male reproductive organs, consisting of anther and filament.
• Anther produces pollen grains.
• Filament supports the anther.
• Carpel is the female reproductive organ, consisting of stigma, style, and ovary.
• Stigma is the receptive surface for pollen.
• Style is a narrow tube connecting stigma to ovary.
• Ovary contains ovules (egg cells).

Pollination

• Pollination is the transfer of pollen from anther to stigma.
• Agents of pollination include bees, butterflies, moths, birds, bats, and wind.
• Types of pollination are self-pollination (pollen from the same plant or flower) and cross-pollination (pollen from a different plant or flower).

Fertilization

• Fertilization is the fusion of a sperm cell with an egg cell.
• Double fertilization is a unique process in flowering plants where one sperm cell fuses with the egg cell to form a zygote and another sperm cell fuses with the polar nuclei to form the endosperm.

Development of the Seed

• A seed is a mature ovule containing a zygote and endosperm.
• An embryo is the developing plant within the seed.
• Endosperm is a nutrient-rich tissue that nourishes the embryo.

Development of the Fruit

• A fruit is a mature ovary that contains one or more seeds.
• Types of fruits include simple, aggregate, and composite fruits.
• Functions of fruits include protection, dispersal, and nutrition for the developing seed.