When a diploid female plant is crossed with a tetraploid male, the ploidy of endosperm cells in the…
When a diploid female plant is crossed with a tetraploid male, the ploidy of endosperm cells in the resulting seed is:
tetraploidy
pentaploidy
diploidy
triploidy.
Solution
Female parent genotype $=2 \mathrm{~N}=2 \mathrm{~A}$
Male Gamete formed $=\mathrm{N}=\mathrm{A}$
Male parent genotype $=2 \mathrm{~N}=4 \mathrm{~A}$
Male Gamete formed $=\mathrm{N}=2 \mathrm{~A}$
Endosperm is formed by the fusion of 2 polar nuclei (from female gamete) and 1 male gamete.
Thus, the ploidy of endosperm $=$ $3 \mathrm{~N}=\mathrm{A}+\mathrm{A}+2 \mathrm{~A}=4 \mathrm{~A}$ (tetraploid)