Explain the role of tapetum in the formation pollen-grain wall.
Solution and Explanation
Tapetum is the innermost layer of the microsporangium. It provides nourishment to the developing pollen grains. During microsporogenesis the cells of tapetum produce various enzymes, hormones, amino acids, any other nutritious material required for the development of pollen grains. It also produces the exine layer of the pollen grains which is composed of the sporopollenin.
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Notes on sexual reproduction in flowering plants
Concepts Used:
Pre-fertilization events - Monoecious Plant
Fertilization in plants may be a process during which they undergo amphimixis in consequence of pollination and germination. During a physicochemical process, the male gametes (known as pollen) infusion with the feminine gametes (known as ovum) forms diploid zygote after carpal pollinates. The whole process happens in a zygote which later germinates into a seed. During the method, what happens is male gametes are transferred into female reproductive organs through pollinators (butterflies, birds, honey bees, bats, and flower beetles). This leads to an embryo being formed during a seed. Flowers are the reproductive organs of angiosperms and reproduce in a completely different method.
Read More: Flower Structure
The two important pre-fertilization procedures are gametogenesis and gamete transfer. The female and male reproductive forms in flowers are the androecium and the gynoecium which distinguishes and goes through development.
"Mono" means single so a monoecious plant is one that bears both male and female sex organs on same plant. The monoecious plant can produce bisexual flowers or unisexual flowers. A dioecious plant is one that bears both male and female sex organs on different plants.
Read Further: Sexual Reproduction in Flowering Plants