ATI RN
Pediatric Genetic Disorders Questions
Question 1 of 5
The maternal serum level of alpha-fetoprotein (AFP) is lower than average in which situation?
Correct Answer: A
Rationale: Low maternal AFP is associated with Down syndrome; high AFP occurs with NTDs, exomphalos, or twins.
Question 2 of 5
This chromosome is:
Correct Answer: C
Rationale: Without a figure, 'Submetacentric' (C) is accepted as per the document. Rationale: Chromosomes are classified by centromere position. Metacentric has a central centromere, acrocentric has it near one end with a short p-arm, submetacentric is off-center, and telocentric has it at the end. 'Interphase chromosome' isn’t a structural type. Submetacentric is plausible for many human chromosomes (e.g., chromosome 1), making 'C' reasonable without context.
Question 3 of 5
One of the following is true about telomerase:
Correct Answer: D
Rationale: Telomeres consist of TTAGGG repeats throughout (D is true). Rationale: Telomerase uses an RNA template (not DNA, B false), extends the 3’ end (C misleading), and is active in cancer (A false). Activity decreases with age (E false). 'D' fits best.
Question 4 of 5
A female with a flattened face, small head, short neck, protruding tongue, small ears, and a poor muscle tone (hypotonia). She probably has a genetic disorder that's caused by?
Correct Answer: A
Rationale: Trisomy 21 (Down syndrome, A) matches these features. Rationale: Flat face, short neck, hypotonia, etc., are classic Down syndrome signs. Monosomy X (Turner) and Trisomy X have different phenotypes (e.g., short stature vs. subtle effects).
Question 5 of 5
Trisomy 47,XYY is a syndrome with signs and symptoms that range from being barely noticeable to learning disabilities, speech delay, low muscle tone. How would you expect this syndrome to have occurred?
Correct Answer: D
Rationale: Paternal nondisjunction causes 47, XYY. Rationale: Nondisjunction in paternal meiosis II results in YY sperm (24, YY), fertilizing an X egg (23, X), yielding 47, XYY. Dispermy or endomitosis would yield triploidy or tetraploidy.