# Consider the cross AaBbCcDdEe*aaBbccddee.What proprtion of the progeny will genotypically resemble the first parent.

Arun
25757 Points
3 years ago
In a cross that size you have a possible 1,024 offspring (counting all possible no matter what). Of that:
There will be 72/1024 that will resemble the first parent, meaning phenotypically all dominant whatever.

As for the second question, do you mean exact duplicates of one of the parents?

ALl offspring will resemble one of the parents because you are talking phenotype - not genotype.

These problems are easy if you take it apart and look at each group of like letters as a single cross. Rather than taking the whole thing at once - break it up.

1. Take Aa x aa first. You'll find that 50% will have the dominant characteristic and 50% will have the recessive characteristic.
2. For the next pair (Bb x Bb) you get 75% (3) that will have the dominant characteristic and 25% (1) totally recessive.
3. Do the same for the rest of the characteristics.
4. When trying to get a total, multipy the characteristics you want, together to get the total.

Using this method you can figure out any genotypic or phenotypic ratio no matter the size of the parents genes for the characteristic.