Triploidy and Tetraploidy involve

Correct Answer: B

Rationale: The correct answer is B because triploidy involves the presence of one extra set of haploid chromosomes, resulting in a total of three sets (3n), while tetraploidy involves two extra sets, resulting in a total of four sets (4n). This leads to abnormal chromosome numbers in cells. Choice A is incorrect because triploidy and tetraploidy do not refer to specific chromosomes but to the number of whole sets of chromosomes. Choice C is incorrect as triploidy and tetraploidy do not directly relate to sexual characteristics. Choice D is incorrect as triploidy and tetraploidy are not caused by chromosome breakage due to radiation but rather by errors in cell division during fertilization.

Correct Answer: B

Rationale: The correct answer is B because maternal serum testing is complicated due to the fact that none of the available tests are individually definitive for fetal abnormalities. This means that a single test cannot conclusively determine the presence or absence of abnormalities, requiring a combination of tests for a more accurate assessment. Other choices are incorrect because A focuses on the quality of tests rather than their definitive nature, C mentions the involvement of health care professionals which is not the main reason for complexity, and D refers to the contents of maternal serum rather than the limitations of individual tests.

Correct Answer: B

Rationale: The correct answer is B because FISH (Fluorescence In Situ Hybridization) uses specific DNA probes that target a particular chromosome or chromosomal region. This allows for the visualization and analysis of specific genetic information without the need for spreads of mitotic chromosomes. Choice A is incorrect because FISH does not necessarily use DNA from whole chromosomes. Choice C is incorrect as chromosomes play a crucial role in genetic information. Choice D is incorrect because while chromosomes contain both DNA and protein, this is not the reason why FISH can provide genetic information without spreads of mitotic chromosomes.

Correct Answer: B

Rationale: The correct answer is B because karyotypes are generated by comparing the binding of probes from the experimental sample to a normal sample. This comparison allows for the visualization of chromosomal abnormalities. By analyzing the differences in probe binding patterns between the two samples, one can identify any genetic variations or mutations present. This method helps in identifying structural abnormalities in chromosomes. Choice A is incorrect because the number of probes used does not determine the generation of karyotypes. Choice C is incorrect as maternal DNA signal versus fetal DNA signal is not relevant to generating karyotypes. Choice D is also incorrect because comparing lymphocytes versus fetal nucleated erythroblasts does not directly lead to the generation of karyotypes.

Correct Answer: B

Rationale: Step-by-step rationale for why answer B is correct: 1. Difficulty getting pregnant is typically related to fertility issues, not necessarily genetic problems. 2. Genetic problems manifest in structural abnormalities, aberrant chromosomes, or inherited conditions. 3. Options A, C, and D all involve indicators of genetic issues through birth abnormalities or aberrant chromosomes. 4. Difficulty getting pregnant does not directly point towards a genetic problem but rather reproductive health issues.