Pollinia are sac like structures

Options

A. Which secerete yellow substance
B. Which are found in megasporangia
C. In which anther lobes are present
D. In which pollen grains are present in mass

Answer

### Step-by-Step Solution:

1. **Definition of Pollinia**: Pollinia are specialized structures found in certain flowering plants, particularly in the family Orchidaceae. They are essentially a mass of pollen grains that are grouped together.

2. **Structure**: Pollinia are described as sac-like structures. They contain a yellow substance, which is the pollen itself. This yellow substance is indicative of the presence of pollen grains, which are the male gametes of the plant.

3. **Origin**: Each pollinium is produced by a single anther. An anther is part of the stamen, which is the male reproductive organ of a flower. The pollen grains within the pollinia are formed through the process of microsporogenesis.

4. **Function in Pollination**: During pollination, the entire mass of pollen grains (the pollinia) is transferred as a single unit from the anther to the stigma of a flower. This process is crucial for fertilization, as it allows the male gametes to reach the female reproductive structures.

5. **Examples of Plants**: Pollinia are commonly found in orchids and some species of milkworts. These plants have evolved to use pollinia as a mechanism to enhance the efficiency of pollination.

6. **Clarification of Terms**: It is important to note that pollinia are not found in megasporangia. Instead, they are associated with the anther of the stamen. The megasporangium is involved in the formation of female gametes (ovules).