Question

How many microsporangia are located at the corners of a typical bilobed anther of angiosperm ?

• A. 2
• B. 4
• C. 8
• D. 1

Answer 1

The Correct Option is B

A typical anther in an angiosperm (flowering plant) is characterized by the following structure:

1. Bilobed Structure: The anther is generally composed of two distinct lobes connected by a region called the connective.
2. Dithecous Condition: Each lobe of the anther contains two chambers or sacs, called thecae. An anther with two lobes, each having two thecae, is described as dithecous.
3. Microsporangia: Each theca represents a microsporangium. A microsporangium is the structure where meiosis occurs to produce microspores, which eventually develop into pollen grains.

Therefore, in a typical bilobed, dithecous anther: 

Number of lobes = 2

Number of microsporangia (thecae) per lobe = 2

Total number of microsporangia = (Number of lobes) \( \times \) (Number of microsporangia per lobe)

Total number of microsporangia = \( 2 \times 2 = 4 \)

When viewed in a transverse section, the bilobed anther often appears somewhat tetragonal (four-sided), with one microsporangium located in each of the four "corners" of the structure.

Thus, there are 4 microsporangia located at the corners of a typical bilobed anther of an angiosperm.

Answer 2

In a typical angiosperm, the anther is bilobed, meaning it has two lobes. Each lobe contains two microsporangia, located at its corners. \[ \text{Number of lobes} = 2, \quad \text{Microsporangia per lobe} = 2 \] \[ \text{Total microsporangia} = 2 \times 2 = 4 \] Thus, the anther has 4 microsporangia.