ATI RN
Pediatric Genetic Questions
Question 1 of 5
The presence of two or more cell lines from different zygotes in a single individual is known as:
Correct Answer: D
Rationale: Chimaerism is two or more cell lines from different zygotes (e.g., fused embryos); mosaicism is from one zygote.
Question 2 of 5
Repeat core sequences consisting of 2,3, or 4 base pairs are known as what?
Correct Answer: B
Rationale: Microsatellites are short tandem repeats of 2-4 base pairs.
Question 3 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 4 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 5 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.