ATI RN
Pediatrics Genetics Questions
Question 1 of 5
Which of the following causes female pseudohermaphroditism?
Correct Answer: C
Rationale: Congenital adrenal hyperplasia (e.g., 21-hydroxylase deficiency) causes excess androgens, masculinizing XX females.
Question 2 of 5
The figure below is the pedigree demonstrating the recurrence of Osteogenesis imperfecta in children with their father unaffected (arrow)
Correct Answer: A
Rationale: OI is AD. Unaffected father with affected kids suggests germline mosaicism; figure unavailable.
Question 3 of 5
Which P arm of the following chromosomes carries rDNA genes?
Correct Answer: B
Rationale: Chromosome 15’s p-arm carries ribosomal DNA (rDNA) genes, part of the nucleolar organizer regions (NORs) on acrocentric chromosomes (13, 14, 15, 21, 22). Answer 'B' is correct. Rationale: rDNA encodes ribosomal RNA, located in the short arms of these chromosomes, with 15 being a known carrier.
Question 4 of 5
A cell is in GO phase. How many chromosomes does it have?
Correct Answer: A
Rationale: G0 is a quiescent phase with no division; a human somatic cell has 46 chromosomes (A). Rationale: G0 cells are diploid (2n=46), not haploid (23) or replicated (92, G2 phase). Answer matches normal somatic count.
Question 5 of 5
Which of the following genetic changes is associated with a female whose karyotype is 46, XY?
Correct Answer: A
Rationale: 46, XY female indicates SRY mutation (A). Rationale: SRY on Y determines maleness; mutations prevent testis development, resulting in female phenotype despite XY karyotype. Monosomy X is 45, X; Triple X is 47, XXX.