Question

Which one of the following is surrounded by a callose wall?

• A. Male gamete
• B. Microspore mother cell
• C. Pollen grain
• D. Egg

Answer 1

The correct option is B Microspore mother cell

Microspore mother cell is surrounded by a callose wall. Each cell of the sporogenous tissue in a microsporangium acts as a potential pollen mother cell (PMC) or microspore mother cell. This undergoes meiotic divisions to form a cluster of four cells called microspore tetrad. The microspore tetrad remain embedded in the callose wall of the pollen mother cell. The callose layer is then digested by an enzyme called callase secreted by tapetum (innermost wall of microsporangium) which then separates the microspore tetrad.