ATI RN
Pediatric Genetic Questions
Question 1 of 5
Which of the following disorders does not show X-linked inheritance?
Correct Answer: B
Rationale: Tay-Sachs is autosomal recessive; others are X-linked.
Question 2 of 5
Which of the following diagnostic techniques is of no value for the diagnosis of neural tube defects?
Correct Answer: B
Rationale: CVS tests chromosomes, not neural tube defects (NTDs); others detect NTDs via AFP or imaging.
Question 3 of 5
The following diseases constitute the Chromosome Instability Syndromes - Ataxia telangiectasia - Fanconi anemia - Bloom syndrome - Xeroderma Pigmentosum: The following statements on the syndromes are correct EXCEPT:
Correct Answer: A
Rationale: A is incorrect; radiation is avoided due to DNA repair defects increasing sensitivity.
Question 4 of 5
Imagine if the humans' diploid chromosomal complement is 10 instead of 46. What would the number of possible combinations of meiosis be:
Correct Answer: B
Rationale: The number of possible chromosome combinations in meiosis is 2^n, where n is the haploid number. If diploid is 10 (2n=10), then haploid is 5 (n=5). Thus, 2^5 = 32 combinations. Answer 'B' (32) is correct. Rationale: Each chromosome segregates independently (Mendel’s Law of Independent Assortment), so with 5 chromosome pairs, there are 2 choices (maternal or paternal) per pair, yielding 32 unique gametes.
Question 5 of 5
All of the following regarding telomeres is true EXCEPT:
Correct Answer: C
Rationale: Telomeres don’t code for genes (C is false). Rationale: Telomeres are TTAGGG repeats (A), shorten with replication (B), and protect chromosome ends (D). They’re non-coding, and telomerase activity is high in cancer (E), making 'C' the exception.