Question

Which pair of the following cells in the embryo sac are destined to change their ploidy after fertilization?

• A. Synergids and eggs cell
• B. Central cell and antipodals
• C. Egg cell and central cell
• D. Antipodals and synergids

Hint:

The central cell fusion is called "Triple Fusion" because it involves three nuclei, resulting in triploid endosperm. This provides the nutrition needed for the developing diploid embryo.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Double fertilization is unique to angiosperms. It involves two separate fusion events. Ploidy refers to the number of sets of chromosomes in a cell. When a haploid male gamete fuses with another cell, the resulting cell's ploidy increases.
Step 2: Detailed Explanation:
1. The Egg Cell: It is haploid (\(n\)). It fuses with one male gamete (\(n\)) to form a diploid Zygote (\(2n\)). The ploidy changes from \(n\) to \(2n\). 2. The Central Cell: It contains two polar nuclei (\(n+n\)). It fuses with the second male gamete (\(n\)) to form the Primary Endosperm Nucleus (PEN), which is triploid (\(3n\)). The ploidy changes from \(n+n\) to \(3n\). 3. Other Cells: Synergids and antipodals are haploid (\(n\)), but they do not participate in fertilization; instead, they degenerate after fertilization without changing their ploidy.
Step 3: Final Answer
The egg cell and central cell are the cells that change their ploidy after fertilization.