Question

Is there a simple way to understand test cross of dihybrid plants? involving punnette square?

Answer 1

punnett square
I always use this method for my genetic question.

Answer 2

Yes - Punnett squares are very useful for this. A test cross is recessive for all traits of interest - so for a dihybrid cross that means, aabb where a is the first gene and b is the second.

Answer 3

thank you! However my teacher loves to give us questions where she provide us with the ratio of offsprings and we have to find the parental genotype. How do I do this kind of questions??

Answer 4

even my teacher @Natshane

Answer 5

hehehehe....I'm asking YY to teach me after class tests...

Answer 6

Use punnett square.

Let say a couple has one AB type child and one O type child.
You draw punnett square and filling in the child's genotype. The middle box is filled by AB and the bottom right is by O-type. Since the child receive each allele from each parent, you can 'trace back' the parental genotype. If the child is AB, one parent will have one A allele and the other will have B allele. If the child is O type, he receive each O allele from each parent. Now you can roughly figure the parent's genotype.

I hope this helps.