If the amount of DNA and number of chromosome in a pollen grain are 20 pg and 16 respectively, then what was the amount of DNA and number of chromosomes in its microspore mother cell at G2 phase?
(1) 40 pg ; 16 chromosome
(2) 80 pg ; 16 chromosome
(3) 80 pg ; 32 chromosome
(4) 40 pg ; 32 chromosome

Dear student

Please refer the solution below for the said query

The correct option is (3).

The microspore mother cell (MMC) is diploid and produces four haploid pollen grains. If the amount of DNA is 20pg and number of chromosomes is 16  in pollen grain, then amount of DNA and number of chromosomes in MMC will be 80pg and 32 chromosomes respectively in G2 phase. This is because in S phase taking place before G2 phase, only amount of DNA is doubled while the chromosome number remains same.

1 pollen grains contains 20 pg of DNA, then MMC will have 80 pg such that each of the four pollen grains receive 20pg of DNA.

If haploid chromosome number of pollen grain is 16, then diploid chromosome number of MMC will be 32. 



Hope this information clears your doubt about the topic.

Regards

  • 1
What are you looking for?