Kristyn is thrilled to hear she is expecting twins. her doctor informs her that the twins are dizygotic. what does this mean?

The dizygotic twins are also known as non-identical twins or fraternal twins. It refers to two siblings, which originate from distinct eggs or ova that are discharged at the similar duration from an ovary and are fertilized by distinct sperm.  

As the dizygotic or fraternal twins are two distinct fertilized eggs, they generally give rise to two separate placentas, amniotic sacs, and supporting compositions.  

answer; the above answer to the above statement is (true)

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.