For a particular plant, red flowers (A) are dominant over yellow flowers (a). An initial cross was made between a plant that was true-breeding for red flowers and another plant true-breeding for yellow flowers. F1 progeny, all having red flowers, were allowed to self- pollinate and form seeds, which were then planted to generate F2 progeny. Pollen from all the resulting F2 plants was pooled and used to fertilize true-breeding yellow plants. What proportion of the progeny resulting from this cross would be expected to have yellow flowers

The correct answer would be - 1 out of 4 or 25% offspring would be expected to have yellow flowers

Explanation:

Red flowers are dominant over the yellow flower, initially, a cross was made between true-breeding red and true-breeding of yellow flowers

Red flower plant gametes, a  and a and red plants gamete would be  A and A.

so,

       A          A

a     Aa         Aa

a      Aa        Aa

in this cross, all the offspring are red as they have a heterozygous genotype. Now self-pollinating these F1 generation offsprings, gametes would be A and a for both parents:

       A        a

A     AA     Aa

a      Aa     aa

in the f2 generation, there is only 25% of offsprings are yellow flowers.

the diploid number of chromosomes is sometimes represented by the symbol 2n. for the fruit fly, the diploid number is 8, which can be written as 2n = 8, where n represents twice the number of chromosomes in a sperm or egg cell.