Hydatid mole is a type of pregnancy that, without medical intervention, frequently results in the death of the mother. The hydatid mole is thought to result most often from an abnormality in fertilization, such that the egg has two copies of paternal chromosomes, and no maternal DNA. A fetus fails to develop; instead there is rapidly growing chorionic tissue in the placenta, which secretes hCG and thus leads to a positive pregnancy test and outward signs of pregnancy. The first clue to the obstetrician that the pregnancy is abnormal is often the lack of a heartbeat in the first trimester.
A. What is the genotype of the hydatid mole tissue? From the genotype alone, would most science-literate students predict that a normal embryo would form? Explain, indicating what this suggests about maternal and paternal contributions to the embryo.
B. The most common cause of molar pregnancy-related maternal death is a type of cancer called choriocarcinoma, with the hydatid mole being the source and thus resembling a tumor. What characteristic of tumors leads to cancer?
C. While these pregnancies often spontaneously abort, some women may elect to terminate a hydatid molar pregnancy. Is this a special case of elective abortion or is it tumor-removal? Explain.
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