Question

A flower with Tt genotype is cross-pollinated by TT pollens. What will the genotypes of the resulting endosperm and embryo, respectively, be?

• A. $TTT,(TT+tt)$
• B. $(TTT+TTt),TT$
• C. TTt, Tt
• D. $TTt,(TT+Tt)$

Answer 1

The correct option is D $TTt,(TT+Tt)$

Two male gametes are produced by the pollen grain One fuses with the egg cell to form the zygote and the other fuses with 2 polar nuclei to form the diploid zygote. The genotype of the pollen is TT. It fuses with the ovum to form the embryo that can have a genotype TT or Tt. The 2 polar nuclei Tt will have the gametes T and t respectively. Hence on fusion with a male gamete, the genotype of the endosperm will be TTt. Thus the correct answer is option D.