Question

How many microsporangia are found in a monothecous anther?
A. Only one
B. Two
C. Four
D. Many

Answer 1

Hint: An anther is a tetragonal structure containing four microsporangia found at the corners. The microsporangia mature further and are modified to pollen sacs.

Complete Answer:
- Microsporangium is a structure in the plant’s male reproductive organ where the development of pollen takes place.
- A microsporangium appears to have a circular outline when viewed transversely. It is surrounded by four layers such as epidermis, endothecium, middle layers, and tapetum. When the anthers are single chambered, they are termed as Monothecous.
- In the case of Hibiscus, both male and female organs are found on the same flower. The anther is monothecous.

Now, let us find the solution from the option.
- Stamen is the male reproductive part of the flower which consists of two parts anther and filament.
- Anther generally possesses two lobes and each lobe consists of two pollen sacs or microsporangia. Monothecous is the single lobe bearing anther.

Thus, the correct option is B i.e. Two.

Note: A monothecous stamen consists of only one-lobed anther with two pollen chambers, also called bisporangiate. It is seen in Malvaceae. A dithecous stamen has two lobes of anthers with four pollen chambers, also called tetrasporangiate. Sterile anthers are seen in staminode stamens, as found in Cassia.