Question

When a hybrid (AaBbCcDd) is selfed then the genotypes AABbCCDd, AaBBCcDd, AaBbCcDd, aabbccdd would be in a proportion of?

• A. $2:4:8:21$
• B. $4:8:16:1$
• C. $4:8:16:27$
• D. $8:4:16:81$

Answer 1

The correct option is B $4:8:16:1$

The tetrahybrid cross of AaBbCcDd can be easily calculated by assuming their independent assortment.

The probability of both the alleles same is 1/4

The probability of both alleles different is 1/2

Hence when we calculate this for all the conditions AABbCCDd, AaBBCcDd, AaBbCcDd, aabbccdd is 4:8:16:1

So the correct answer is ' 4 : 8 : 16 : 1'.