Microsporogenesis:

• Microsporogenesis is the formation of microspores inside the microsporangia (or pollen sacs) of seed plants.
• Stamens are reproductive organs in flowering plants and are known as microsporophyll.
• Each anther of four pollen sacs called micro sporangia. It consists of outer wall, a single layer of nutritive cells called tapetum and central mass of pollen mother cells (PMC) or microsporocyte with 2n chromosome compliment.
• Each pollen mother cell undergoes meiosis a…

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Fact About Types of Pollen Grains

1. In Asclepiadaceae (Calotropis) and Orchidaceae family, all the pollen grains joined together to form “Pollinium”. Pollinium of Calotropis is also called “Translator apparatus”
2. More than four pollen grains are found in tetrad called “Polyspory” e. g. Cuscuta.
3. In some plants, four pollens of tetrad join together permanently are called “Compound pollens” e. g. Drosera, Typha, Drimys and Elodea.
4. Compound pollens of Mimosaceae (Mimosa) family contains 6 - 8 or 64 po…

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Structure of Microspore or Pollen Grain

• Pollen grain is the first cell of a male gametophyte.
• Pollen grain is termed as immature male gametophyte. Usually, they are in round shape. Pollen grain surrounded by two distinct layers. The outer layer (wall) is thick, rigid and ornamented, called exine. This layer is formed by cutin and sporopollenin. Sporopollenin is highly resistant material. It is non-biodegradable.
• Due to the presence of sporopollenin, fossils of pollen grain are always found in good c…

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