Why does an embryo with a balanced translocation have the same chance for normal development that an embryo with a normal karyotype has?
A)The translocation stimulates DNA repair mechanisms to correct the problem before commitment occurs.
B)The embryo's somatic cells are unaffected, expressing a normal karyotype; only germline cells express the translocation.
C)Although the location of the genetic material is abnormal with a balanced translocation, there are no missing or extra alleles.
D)When a zygote with a balanced translocation reaches the embryo stage without a spontaneous abortion, the risk for abnormal development decreases.

Question

Quizplus · Accepted Answer

The most important part of the beginning process in which a zygote is formed that has half its chromosomal material from its father and half from its mother is that the zygote inherits exactly the right amount of genetic material. The actual location of the genetic material is less important for normal growth, development, and function. With a balanced translocation, the right number of alleles is present (no more and no less) in both somatic and germline cells, but they are not all located in their customary places. Because this translocation is balanced, there is no specific risk either for abnormal development or miscarriage of the fetus who is a balanced translocation carrier. Neither phenotype nor physiologic function is affected. DNA repair mechanisms correct only individual base placement, not translocations.

Why Does an Embryo with a Balanced Translocation Have the Same