In Zinnia Plants (N = 16),the Chromosomes of Autotetraploids Pair

Essay

In Zinnia plants (n = 16),the chromosomes of autotetraploids pair in twos.The locus for flower color (R = red,r = white)is close to the centromere on chromosome 5,and the locus for plant height (D = tall,d = dwarf)is also closely linked to the centromere on chromosome 11.Both dominant alleles show full dominance over any number of recessive alleles.
a)If you are observing meiosis in tetraploid Zinnias,what is the total number of bivalents (chromosome pairs)that will be visible during prophase I? Explain.
b)In a pollen cell from a tetraploid plant,how many chromosomes will be present?
c)If a tetraploid plant of genotype R/R/r/r;D/D/D/D is selfed,what proportion of progeny will be white flowered and tall?
d)If a tetraploid plant of genotype R/r/r/r;D/D/D/D is selfed,what proportion of progeny will be white flowered and tall?
e)If a tetraploid plant of genotype R/R/r/r;D/D/d/d is selfed,what proportion of progeny will be white flowered and dwarf? What proportion will be red flowered and tall?