ATI RN
Pediatric Genetics Questions
Question 1 of 5
Which of the following findings on prenatal ultrasound examination would not raise suspicion of a chromosome abnormality?
Correct Answer: D
Rationale: Monozygotic twins are not inherently linked to chromosomal abnormalities; others are (e.g., duodenal atresia with Down syndrome).
Question 2 of 5
The number of human chromosomes by the end of anaphase of meiosis II is:
Correct Answer: C
Rationale: By the end of anaphase II in meiosis, homologous chromosomes have separated (meiosis I), and sister chromatids separate in meiosis II, resulting in haploid cells. Humans have a diploid number of 46 (2n=46), so each gamete at the end of meiosis II has 23 chromosomes (n=23). The provided answer 'C' (46) is incorrect; it should be 'B' (23). However, adhering to the document, I list 'C' as given, noting the error. Rationale: Meiosis II mimics mitosis for haploid cells, splitting 23 chromosomes (each with 2 chromatids) into 23 single-chromatid chromosomes per cell.
Question 3 of 5
The practical way to visualize a karyotype of a suspected very large chromosomal deletion, is to:
Correct Answer: B
Rationale: Metaphase (B) is ideal for karyotyping as chromosomes are condensed and aligned, allowing visualization of deletions. Rationale: Colcemid arrests cells in metaphase, enabling clear banding and structural analysis, unlike anaphase (separating) or S phase (replicating).
Question 4 of 5
The figure depicts two possible graphs of an assumed population genetic diversity. In comparison to each other:
Correct Answer: D
Rationale: Crossing over in meiosis increases diversity (D is correct). Rationale: Crossing over (prophase I) shuffles alleles, favoring higher diversity (graph B likely shows more variation). A and B are false (crossing over is meiotic), C reverses logic.
Question 5 of 5
A patient with Klinefelter syndrome can be seen as:
Correct Answer: A
Rationale: Klinefelter is 47, XXY male (A). Rationale: Extra X causes male infertility, tall stature, etc. Females cannot be XXY (SRY on Y); 45, X is Turner syndrome (female).