According to a study in 2013 by van Gameren-Oosterom, individuals with Down syndrome:

Correct Answer: C

Rationale: The correct answer is C. According to a study in 2013 by van Gameren-Oosterom, individuals with Down syndrome often exhibit deficits in cognitive development. This is a common characteristic of Down syndrome, along with other health challenges. Choice A is incorrect because individuals with Down syndrome are at a higher risk of cardiovascular problems, contrary to being unlikely to die from them. Choice B is incorrect as Down syndrome is associated with specific characteristic features such as distinctive facial characteristics, making the statement that they have no specific features incorrect. Choice D is incorrect as individuals with Down syndrome have an extra copy of chromosome 21, resulting in a total of 47 chromosomes, not 46.

Correct Answer: C

Rationale: Sickle-cell anemia is a genetic disorder caused by inheriting two copies of a recessive gene, one from each parent. The correct answer is C. Choice A is incorrect because sickle-cell anemia is not primarily caused by a chromosomal abnormality. Choice B is incorrect as the condition is not linked to a single segment found only on the Y chromosome. Choice D is unrelated as it mentions a decrease in estrogen levels, which is not a cause of sickle-cell anemia.

Correct Answer: C

Rationale: Cystic fibrosis is a genetic disorder caused by inheriting two copies of a recessive gene, one from each parent. This means that both parents must carry at least one copy of the faulty gene for a child to inherit the condition. Choice A is incorrect because cystic fibrosis is not linked to the sex chromosomes. Choice B is incorrect as cystic fibrosis is not caused by an abnormality in the 21st pair of chromosomes but by a specific gene mutation. Choice D is also incorrect as cystic fibrosis is not related to the Y chromosome, which is specific to males.

Correct Answer: D

Rationale: The correct answer is the Alpha-fetoprotein (AFP) assay. This blood test measures the level of AFP in a pregnant woman's blood, aiding in the detection of neural tube defects and certain chromosomal abnormalities in the fetus. Choice A, artificial insemination, is a method used to facilitate fertilization and is not related to detecting fetal abnormalities. Choice B, amniocentesis, involves collecting amniotic fluid for genetic testing, not directly measuring AFP levels. Choice C, endometriosis, is a medical condition involving abnormal tissue growth and is not a procedure for detecting fetal abnormalities. Therefore, the Alpha-fetoprotein (AFP) assay is the most appropriate option for detecting neural tube defects such as spina bifida and certain chromosomal abnormalities.

Correct Answer: D

Rationale: The correct answer is D: WBC count 32,000/mm3. A WBC count of 32,000/mm3 is significantly elevated in a newborn and could indicate an infection, which needs immediate attention and intervention. High white blood cell counts in newborns can be concerning as they may suggest an ongoing infection or other underlying issues that require prompt medical evaluation and treatment. Choices A, B, and C are within normal ranges for a newborn and would not typically warrant immediate reporting to the provider. Hgb levels of 20 g/dL (Choice A) are high for newborns, but this is not as concerning as a significantly elevated WBC count. Bilirubin levels of 2 mg/dL (Choice B) are within normal limits for a newborn and do not indicate immediate issues. Platelet count of 200,000/mm3 (Choice C) is also within the normal range for a newborn and would not require immediate reporting.