Step 1: Identify the type of cells mentioned.
The calyx is a part of the flower and its cells are somatic (diploid) cells. If the number of chromosomes in these cells is 16, then the diploid number is 2n = 16.
Step 2: Determine the haploid number.
In flowering plants, gametes (male and female) are haploid. The haploid number is half of the diploid number.
\[
n = \frac{16}{2} = 8
\]
So, each gamete contains 8 chromosomes.
Step 3: Understand double fertilisation.
In double fertilisation, two male gametes participate in fertilisation:
• One male gamete fuses with the egg cell to form the zygote (2n).
• The other male gamete fuses with the two polar nuclei to form the endosperm.
Step 4: Calculate chromosomes in the endosperm.
Each polar nucleus has n = 8 chromosomes.
Two polar nuclei together:
\[
8 + 8 = 16
\]
When the second male gamete (8 chromosomes) fuses with them:
\[
16 + 8 = 24
\]
Step 5: Determine the ploidy of the endosperm.
Thus, the endosperm becomes triploid (3n) and contains 24 chromosomes.
Final Answer:
The endosperm formed after double fertilisation will contain 24 chromosomes.