Chorionic villi sampling (CVS) is used to test for genetic disorders in the fetus and can be
performed early in gestation (8-10 weeks). The recommended method of CVS is to insert a
probe with a needle on the end through the cervix and remove a sample of chorionic villi to be
analyzed.
23. Which is a correct description of chorionic villi?
A. They contain cells whose nuclei differ genetically from cells of the fetus.
B. They form part of the placenta.
C. They are developed from the endometrium.
D. They are found in the digestive tract of the fetus.