ATI RN
Pediatric Genetics Questions
Question 1 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 2 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 3 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).
Question 4 of 5
A child person with clinical features that include: cardiovascular, brain with neurological, renal, gastrointestinal, respiratory, and skeletal malformations, craniofacial abnormalities such as prominent occiput, hand and feet anomalies including clenched hand. This patient is most probably affected with:
Correct Answer: A
Rationale: Trisomy 18 (Edwards syndrome, A) fits. Rationale: Clenched hands, multiple organ defects, and craniofacial issues (e.g., prominent occiput) are hallmark Edwards features. Down (B, D) lacks these specifics; Turner (C) differs (e.g., lymphedema).
Question 5 of 5
The chromatin in interphase and in M phase
Correct Answer: C
Rationale: Chromatin is decondensed in interphase (for gene expression) and condensed in M phase (mitosis, for segregation). 'C' (Decondensed, Condensed) is correct. Rationale: Interphase chromatin is diffuse to allow transcription, while M phase (prophase to metaphase) condenses chromosomes into visible, compact structures for division.