In a cross of AB and ++, 750 are parental types out of 1000 progenies. The map unit between A and B is

Solution(By Examveda Team)

In a cross of AB and ++, 750 are parental types out of 1000 progenies. The map unit between A and B is 75 map units.
A map unit is a unit for measuring genetic linkage. It is defined as the distance between chromosome positions for which the expected average number of intervening chromosomal crossovers in a single generation is 0.01.
Map unit between A and B
$$\eqalign{ & = \frac{{{\text{no}}{\text{. of recombinants}}}}{{{\text{total no}}{\text{. of offsprings}}}} \cr & = \frac{{750}}{{1000}} \times 100 \cr & = 75{\text{ maps unit}}{\text{.}} \cr} $$