n plants you want to know whether two loci P and Q are linke

n plants, you want to know whether two loci, P and Q, are linked and if so, what their map distance is. You do a testcross with a P/pQ/q plant and observe the following progeny. Based on this information, what are the genotypes of the parents? Genotype Progeny P/pQ/q 21 p/pq/q 25 P/pq/q 216 p/pQ/q 238

Please show work

Solution

Answer:

Test cross of Pp Qq will have the offspring with the following genotypes.

Pp Qq* pp qq ---> Pp Qq (1/4), Pp qq (1/4), pp Qq (1/4), pp qq (1/4)

The given progeny number is, Pp Qq (21, recombinant), Pp qq (216, parental), pp Qq (238, parental), pp qq (25, recombinant)

Thus, the parental genotype are, Pp qq and pp Qq. Because their progeny percent is always equal to or more than 50% of total progeny.