Maternal blood tests for three pregnant women revealed they would be having boys, yet subsequent ultrasound images showed all three were pregnant with girls. In each case Y chromosome sequences in each mother's blood originated from transplanted organs they had received from men! This demonstrates one dramatic example of a limitation of genetic analysis of maternal blood samples. What kind of information could have been collected from each mother in advance of these tests to better inform physicians prior to performing each test?

Video transcript

Hello, everyone and welcome to today's video. So which of the following statements about preimplantation, genetic diagnosis or PGD is going to be correct. Let's go over each of our answer choices so that we may solve the problem. So let's begin by answer choice. The embryonic cell must be created from in vitro fertilization. Well, this is going to be incorrect because it can also be created from in vitro fertilization. It can be done in a lab. So this is an incorrect statement and we're going to cancel it out. Then we have the salt to be analyzed to be taken at a later stage of embryo development. When all cells have completely divided, this is going to be incorrect because the cell must be taken at an earlier stage. So this is an incorrect statement and we're going to cancel it out. And then it involves genetic analysis of a single embryonic cell just as the answer choices were stating we're taking a single embryonic cell from the stage of development and we are analyzing it. So this is going to be a correct answer choice and we're going to highlight it as a final answer to our question. I really hope this video helped you and I want to see you on the next one.