A flower with Tt genotype is cross pollinated by TT pollens . what will be the genotype of the resulting endosperm and embryo?
Dear student,
Please find below the solution to the asked query
During pollination and fertilisation, the pollen grain produces two sperm nuclei. One of the sperm nuclei fuses with the egg and forms diploid zygote and then embryo.
The other fuses with two polar nuclei and forms triploid endosperm.
Here genotype of staminate flower or pollen grain is TT, so it will produce only one type of gamete i.e T.
Genotype of pistillate flower is Tt, so it will produce two types of gametes i.e T and t.
Now, female gametocyte or embryo sac will receive either T or t during meiosis. The embryo sac contains one egg cell, 3 antipodal cells, 2 synergids and two polar nuclei. All these cells have same genotype.
The gametocyte or embryo sac that receives T allele will have all cells with T allele and the gametocyte or embryo sac that receives t allele will have all cells with t allele.
Thus, when pollen with T allele fertilises egg cell with T allele, the genotype of embryo will be TT and when pollen with T allele fertilises egg cell with t, the genotype of embryo will be Tt.
Now, when pollen with T allele fertilises two polar nuclei with both T allele, the genotype of endospore will be TTT and when pollen with T allele fertilises two polar nuclei with both t allele the genotype of endospore will be Ttt.
Thus, the genotype of embyo will be either TT or Tt.
The genotype of endosperm will be either TTT or Ttt.
Hope this information will clear your doubts about the genotype of the resulting endosperm and embryo.
If you have any more doubts just ask here on the forum and our experts will try to help you out as soon as possible.
Regards
Please find below the solution to the asked query
During pollination and fertilisation, the pollen grain produces two sperm nuclei. One of the sperm nuclei fuses with the egg and forms diploid zygote and then embryo.
The other fuses with two polar nuclei and forms triploid endosperm.
Here genotype of staminate flower or pollen grain is TT, so it will produce only one type of gamete i.e T.
Genotype of pistillate flower is Tt, so it will produce two types of gametes i.e T and t.
Now, female gametocyte or embryo sac will receive either T or t during meiosis. The embryo sac contains one egg cell, 3 antipodal cells, 2 synergids and two polar nuclei. All these cells have same genotype.
The gametocyte or embryo sac that receives T allele will have all cells with T allele and the gametocyte or embryo sac that receives t allele will have all cells with t allele.
Thus, when pollen with T allele fertilises egg cell with T allele, the genotype of embryo will be TT and when pollen with T allele fertilises egg cell with t, the genotype of embryo will be Tt.
Now, when pollen with T allele fertilises two polar nuclei with both T allele, the genotype of endospore will be TTT and when pollen with T allele fertilises two polar nuclei with both t allele the genotype of endospore will be Ttt.
Thus, the genotype of embyo will be either TT or Tt.
The genotype of endosperm will be either TTT or Ttt.
Hope this information will clear your doubts about the genotype of the resulting endosperm and embryo.
If you have any more doubts just ask here on the forum and our experts will try to help you out as soon as possible.
Regards