Formation of Pollen

Edexcel AS-level BiologyMeiosis and Sexual ReproductionLesson 20 of 28

Pollen grains develop inside the anthers of the stamens. A young anther contains four pollen sacs, each filled with diploid pollen mother cells (2n). Around each sac is a layer of nutritive cells, the tapetum, which supplies the developing pollen with nutrients.

The stages are:
• Each pollen mother cell divides by meiosis to form a group of four haploid cells, called a tetrad.
• The cells of the tetrad separate, and each becomes an immature pollen grain (a microspore, n).
• The nucleus of each immature pollen grain divides by mitosis, giving a tube nucleus and a generative nucleus.

More in Meiosis and Sexual Reproduction

• Oogenesis
• The Male Gamete
• The Female Gamete
• Gametogenesis in Plants
• Formation of Plant Egg Cells
• Pollination
• Internal Fertilisation
• External Fertilisation

All 28 lessons in Meiosis and Sexual Reproduction · All Edexcel AS-level Biology topics