Rachel is excited when her pregnancy test is positive,but an ultrasound scan at 6 weeks shows no heartbeat.What might have happened is

Question

Quizplus · Accepted Answer

A polar body is a non-functional cell that is produced during oogenesis (the development of eggs). It contains a haploid set of chromosomes but very little cytoplasm. It is possible, although very rare, for a polar body to be fertilized by a sperm. The resulting zygote would have a haploid set of chromosomes from the polar body and a haploid set of chromosomes from the sperm. In this case, the zygote would not have developed properly, resulting in the absence of a heartbeat on the ultrasound. This is known as a "polar body twin" or "half-identical twin."

Rachel Is Excited When Her Pregnancy Test Is Positive,but an Ultrasound