Ultrasound is an excellent method for prenatal screening because

Correct Answer: C

Rationale: The correct answer is C: It is a non-invasive technique. Ultrasound is safe and non-invasive, making it ideal for prenatal screening as it does not pose any risk to the mother or the fetus. Choices A and B are incorrect because ultrasound must be performed by a trained healthcare professional in a medical setting, not at home, and it requires specialized equipment and expertise, making it more expensive and reliant on advanced technology. Choice D is incorrect as choices A and B are not true, making it not all of the above.

Correct Answer: C

Rationale: The correct answer is C because during Fluorescent In Situ Hybridization (FISH), the fluorescent probes specifically bind to target DNA sequences on chromosomes. When there is a rearrangement, the probes will separate or change color at the breakpoints, indicating the presence of a chromosomal rearrangement. This makes it easy to detect the location and extent of the rearrangement. Choice A is incorrect because FISH probes can bind to both normal and rearranged chromosomes. Choice B is incorrect because FISH probes do not cause chromosomes to change color; they simply show the presence of rearrangements through color separation. Choice D is incorrect because FISH probes are not full of rearranged chromosomes; they are used to detect rearrangements on chromosomes.

Correct Answer: D

Rationale: The correct answer is D, All of the above, because families with recurrent genetic problems have various options to consider. Decision not to have children can prevent passing on genetic issues. Adoption allows them to expand their family without genetic concerns. Sperm or egg donation provides the option of having biological children through a different genetic source. Therefore, all options - not having children, adoption, and donor options - are available to families dealing with recurrent genetic problems.

Correct Answer: D

Rationale: The correct answer is D, "All of the above." Unbalanced translocations, aneuploidy, and aneusomy can all be recurrent in a family due to genetic factors being passed down through generations. Unbalanced translocations involve an abnormal chromosomal arrangement, aneuploidy is the presence of an abnormal number of chromosomes, and aneusomy refers to an abnormal number of copies of a particular chromosome. These genetic abnormalities can be inherited and recur in families, making D the correct choice.

Correct Answer: C

Rationale: The correct answer is C because the effective dose is a measurement that accounts for the different biological effects of various types of radiation on tissues or organs. It takes into consideration factors like the type of radiation, the energy, and the sensitivity of the exposed tissue. This makes it a more accurate representation of the potential harm caused by radiation exposure compared to simply measuring the amount of radiation present in the body (choice A) or accounting for shielding effects (choice B). Choice D is incorrect because the effective dose is not the same for gamma rays, beta particles, and alpha particles due to their different penetration abilities and biological impacts.