Plant and Animal Reproduction

• Pollen grains are the carriers of male gametes and ovule have the egg in seed plants.
• In bisexual, self-fertilising plants, e.g., peas, transfer of pollen grains to the stigma is relatively easy as anthers and stigma are located close to each other;
• But in cross pollinating plants (including dioecious plants), a specialised event called pollination facilitates transfer of pollen grains to the stigma.
• Pollen grains germinate on the stigma and the pollen tubes carrying the male gametes reach the ovule and discharge male gametes near the egg.
• In dioecious animals, since male and female gametes are formed in different individuals, the organism must evolve a special mechanism for gamete transfer.
• Successful transfer and coming together of gametes is essential for the most critical event in sexual reproduction, the fertilisation.

Test your knowledge of the process of sexual reproduction in seed plants and animals, including the role of pollen grains, pollination, and the transfer of gametes.