Question

A dithecous anther consists of ________ microsporangia, _______ in each lobe.
A. Four, two
B. Two, one
C. Two, two
D. Four, one.

Answer 1

Hint: In flowering plants, the male reproductive organ comprises a structure that is involved in pollen production is called the stamen. Stamen is composed of two parts. These are anther and filament. The anther is responsible for containing the microsporangia. Anther possesses a knob-like structure and filament resembles the stalk.

Complete answer: Sporangium or sporangia is a sac-like structure that is involved in the production of spores. Terrestrial plants comprise the sporangia in the male reproductive organ which is called microsporangia. Microsporangia is responsible for producing male gametophytes. Microsporangia is only found in tracheophytes which possess a heterosporic life cycle. Example: Azolla sp.
When another male reproductive organ possesses two lobes is called dithecous anther or dithecous anther. Dithecous anther comprises four microsporangia. The four microsporangia are found distributed evenly in the two lobes of the dithecous anther. Thus each lobe of dithecous anther bears 2 microsporangia.
So, the correct answer is “Option A,dithecous anther comprises four microsporangia, two in each lobe. ”.

Additional Information:
Heterosporous plant: The plants which are involved in the production of two different sized spores having different sexes is called heterosporous plant. And their life cycle is known as the heterosporic life cycle.
Terrestrial plants comprise the sporangia in the female reproductive organ, which is named megasporangium. Megasporangia is involved in the formation of female gametocytes.

Note: The process by which microsporangia produce microspore is called microsporogenesis. Microsporocytes are produced from the microsporangia. Microsporocytes are also known as the pollen mother cell. Pollen mother cell forms four haploid gametes by meiosis cell division. These haploid gametes are known as microspore.