Pre Fertilisation Structures And Events

To address the question about the number of microsporangia present at the corners of a typical bilobed anther of an angiosperm, let's break down the structure of an anther in flowering plants:

1. The anther is the part of the stamen where pollen is produced. It is typically bilobed, meaning it has two lobes.
2. Each lobe of the anther contains two microsporangia, which are the structures that produce and contain pollen grains. These are often also referred to as pollen sacs.
3. Since each lobe has two microsporangia, and there are two lobes in a typical anther, the total number of microsporangia is calculated as follows:

Therefore, there are a total of 4 microsporangia located at the corners of a typical bilobed anther in angiosperms.

Correct Answer: 4

To evaluate the accuracy of the given statements, we need to understand the structure and function of the microsporangium in plant biology.

Statement 1: The innermost layer of microsporangium is tapetum.

The microsporangium is a part of the stamen where pollen grains develop. It typically consists of four layers:

1. Epidermis – The outermost layer.
2. Endothecium – Below the epidermis, aids in dehiscence.
3. Middle layers – Two or more layers of cells.
4. Tapetum – The innermost layer, providing nourishment to developing pollen grains.

Therefore, Statement 1 is correct as the tapetum is indeed the innermost layer of the microsporangium.

Statement 2: Cells of tapetum possess dense cytoplasm, more than one nucleus, and nourish developing pollen grains.

The tapetum's cells are known for having dense cytoplasm and are often multinucleate. This characteristic helps the tapetum in its primary function, which is to provide nourishment to the developing pollen grains through the secretion of enzymes and nutrients. Thus, Statement 2 is also correct.

Since both statements correctly describe the characteristics and role of the tapetum, the correct option is:

Both Statements 1 & 2 are correct.

Understanding the structure and function of plant reproductive organs is crucial in botany and helps in understanding the processes involved in plant reproduction and development.