Structure of an Anther MCQ - Practice Questions with Answers

• In a cross-section, the anther is a four-sided tetragonal structure consisting of four microsporangia located at the corners, two in each lobe. 
• Later, the microsporangia develop and become pollen sacs, which are packed with the pollen grains.
• Therefore, a bilobed anther is tetrasporangiate.
• The microsporangia are covered with a common epidermis of the anther.
• The microsporangia develop from the strips of archesporial cells, hence the development of microsporangia is eusporangiate.
• The archesporial cell divides to form an outer parietal cell and an inner sporogenous cell.
• The parietal cells divide further to produce micro sporangial wall made up of endothecium, middle layers and tapetum.
• The sporogenous cells develop to become microspore mother cells.

Walls of Microsporangia:

• There are four types of layers in the walls of microsporangia:
  • Epidermis
  • Endothecium
  • 1-3 middle layers
  • Tapetum 
• The cells of endothecium develop fibrous thickening.
• Between the two microsporangia in one anther lobe, the endothecium is thin-walled and forms the stomium or line of dehiscence of the anther.
• The cells of tapetum are filled with dense protoplasmic content as well as nutrients.
• They may become multinucleated or their nuclei may become polyploid.
• Tapetum can be of two types:
  • Amoeboid 
  • Secretory 
• Tapetum nourishes the developing microspore mother cells and pollen grains.
• It produces Ubisch granules that contain sporopollenin for exine formation.