PLEASE READ CAREFULLY. THIS IS THE SECOND TIME I AM POSTING THIS BECUASE THE PRE

Question

PLEASE READ CAREFULLY. THIS IS THE SECOND TIME I AM POSTING THIS BECUASE THE PREVIOUS TUTOR DID NOT READ THE QUESTION AND RUSHED TO ANSWER. I WANT TO KNOW THE ANSWER TO THE QUESTION BELOW. HOW IS IT POSSIBLE the question asks that " Three sons are colour blind and one son has normal vision. "

USE Punnett square for ALL PROBLEMS

Q. A woman with normal vision reproduces with a man with normal vision. Three sons are colour blind and one son has normal vision. Explain how this occurred using the Punnett square.

Explanation / Answer

Remember that for any gene,

Homozygous dominant = "AA"
Heterozygous (‘carrier’) = "Aa"
Homozygous recessive = "aa"

two heterozygous parents are crossed. Remember, to be heterozygous means an organism has both a dominant and a recessive gene. Usually, the dominant gene masks the expression of the recessive one. Once the Punnett square has been filled out, the results look like this:

So that, cross both parents

uneffected carrier father Aa X Uneffected carrier mother Aa

So that All three childs are normal and one child is effected from Colour blind.

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.