Question

In a particular plant with bilobed dithecous anther, there were 50 Pollen Mother Cells. Only 25% could develop their pollen tubes. Calculate the number of pollen grains that would proceed for fertilisation.

Hint:

Remember: 1 Microspore Mother Cell (MMC) $\rightarrow$ 4 Pollen grains, but 1 Megaspore Mother Cell $\rightarrow$ only 1 functional Egg.

Answer 1

Step 1: Understand the structure of the anther.
A typical angiosperm anther is bilobed and dithecous. Each anther contains 4 pollen sacs (microsporangia). However, each Pollen Mother Cell (PMC) undergoes meiosis to produce 4 haploid pollen grains.

Step 2: Calculate the total pollen grains produced.
Number of Pollen Mother Cells = 50.
Each PMC produces 4 pollen grains.

Total pollen grains formed:
\[ 50 \times 4 = 200 \]

Step 3: Determine how many pollen grains form pollen tubes.
Only 25% of the pollen grains could develop their pollen tubes.

\[ 25\% \text{ of } 200 = \frac{25}{100} \times 200 \] \[ = 50 \]

Step 4: Interpret the result.
Only those pollen grains that successfully develop pollen tubes can participate in fertilisation.

Final Answer:
The number of pollen grains that would proceed for fertilisation is 50.