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: D

Rationale: The correct answer is D: 1 cup of cooked broccoli. Broccoli is an excellent source of calcium, making it a suitable choice for a vegan diet. Avocado (Choice A), banana (Choice B), and potato (Choice C) are not significant sources of calcium compared to broccoli. Avocado and banana are primarily sources of other nutrients like healthy fats and potassium, respectively. Potato is a good source of vitamin C and potassium but not calcium. Therefore, for a pregnant client following a vegan diet and seeking calcium-rich foods, cooked broccoli is the most appropriate choice.

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: C

Rationale: Nasal stuffiness is a common symptom during pregnancy due to increased blood flow and hormonal changes. This symptom is caused by the increased blood volume and hormonal changes that lead to swelling of the nasal passages. Choices A, B, and D are incorrect. Stomach emptying rate does not significantly change during pregnancy; the uterus does not double in size at 24 weeks but rather grows steadily, and nipples typically darken in color due to increased pigmentation.

Correct Answer: B

Rationale: Syphilis is the correct answer. Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum. If left untreated, it can progress through various stages and potentially attack major organ systems, causing severe complications. Rubella, Cystic fibrosis, and Phenylketonuria are not sexually transmitted infections. Rubella is a viral infection, Cystic fibrosis is a genetic disorder affecting the lungs and digestive system, and Phenylketonuria is a genetic metabolic disorder. These conditions do not typically affect major organ systems in the same way as untreated syphilis.