Sexual Reproduction in Living Organisms

Reproduction in Animals and Plants - Revision Sheet

1. 📌 Essentials

• Reproduction ensures species continuity via gamete union and fertilization.
• Main life stages: larva, juvenile, adult.
• Gametes: female (ovule), male (spermatozoid).
• Fertilization: union of gametes forming a zygote.
• Reproductive modes: oviparous (eggs outside), viviparous (inside).
• Fertilization: internal (inside female), external (environment).
• Animal reproduction involves mating (accouplement) and sperm transfer.
• Plant reproduction involves pollination, fertilization, seed development, germination.
• External fertilization releases many gametes to increase survival.
• Flower structures facilitate pollination and fertilization.

2. 🧩 Key Structures & Components

• Gametes — reproductive cells: ovule (female), spermatozoid (male).
• Zygote — fertilized egg, begins development.
• Ovary — contains ovules in plants.
• Pollen — male gametophyte in plants.
• Flower parts:
  • Stamen — produces pollen.
  • Pistil — contains ovules.
• Fertilization structures:
  • Pollen tube — guides sperm to ovule.
• Reproductive tract — in animals, transports sperm to egg.

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