is a fatal genetic neurologic disorder whose onset is in middle age

HESI LPN

HESI Maternal Newborn

1. Which of the following is a fatal genetic neurologic disorder whose onset is in middle age?

A. Tay-Sachs disease
B. Duchenne muscular dystrophy
C. Hemophilia
D. Huntington’s disease

Correct answer: D

Rationale: Huntington's disease is a fatal genetic neurologic disorder characterized by progressive nerve cell degeneration in the brain. It typically manifests in middle age with symptoms such as involuntary movements, cognitive decline, and psychiatric disturbances. Tay-Sachs disease (Choice A) is a genetic disorder that primarily affects the nervous system in early childhood, not middle age. Duchenne muscular dystrophy (Choice B) is a genetic disorder that primarily affects muscle function and usually presents in early childhood. Hemophilia (Choice C) is a genetic disorder related to blood clotting, and its onset is not typically in middle age.

2. Which of the following statements is true of sickle-cell anemia?

A. It is typically managed with treatments such as pain relief medications.
B. It is caused by a mutation in the beta-globin gene.
C. It leads to the obstruction of small blood vessels and decreased oxygen delivery.
D. It is more prevalent in individuals of African, Mediterranean, Middle Eastern, and Indian descent.

Correct answer: C

Rationale: The correct answer is C. Sickle-cell anemia results from a mutation in the beta-globin gene, causing red blood cells to become sickle-shaped. These misshapen cells can obstruct small blood vessels, leading to reduced oxygen delivery to tissues. Choices A, B, and D are incorrect because sickle-cell anemia is typically managed with treatments such as pain relief medications, hydration, and in severe cases, blood transfusions. It is caused by a specific mutation in the beta-globin gene, not by the inability to metabolize phenylalanine. Additionally, sickle-cell anemia is more prevalent in individuals of African, Mediterranean, Middle Eastern, and Indian descent, not exclusive to any specific gender.

3. Monozygotic (MZ) twins share _________ percent of their genes.

A. 100
B. 75
C. 50
D. 25

Correct answer: A

Rationale: Monozygotic (MZ) twins share 100% of their genes because they originate from the same fertilized egg that splits into two, resulting in identical genetic material for both twins. Choice B (75%) is incorrect as it implies a partial genetic similarity, which is not the case for MZ twins. Choice C (50%) is incorrect as it suggests half of the genes are shared, which is applicable to dizygotic (DZ) twins, not MZ. Choice D (25%) is incorrect as it indicates minimal genetic sharing, which is not true for MZ twins.

4. A client who has mild preeclampsia and will be caring for herself at home during the last 2 months of pregnancy is receiving teaching from a healthcare provider. Which statement by the client indicates an understanding of the teaching?

A. “I will count baby’s kicks every other day.”
B. “I will alternate the arm used to check my blood pressure.”
C. “I will consume 50 grams of protein daily.”
D. ---

Correct answer: B

Rationale: The correct answer is B. Alternating arms for blood pressure checks ensures more accurate readings and helps monitor preeclampsia. Option A, counting baby's kicks every other day, is not specific to managing preeclampsia. Option C, consuming 50 grams of protein daily, is important for a healthy diet during pregnancy but does not directly relate to preeclampsia management.

5. In the context of an average ejaculation, which of the following statements is true about sperm?

A. The average count of sperm in the ejaculate is 2.5 billion.
B. Sperm in the ejaculate find the ovum by following the current of the fluid coming from the cervix.
C. Only 1 in 1,000 sperm in the ejaculate will ever approach an ovum.
D. Most of the sperm in the ejaculate move about in a random pattern in the vagina.

Correct answer: C

Rationale: Out of millions of sperm released during ejaculation, only a small fraction, about 1 in 1,000, will approach the ovum. This statement is true as sperm face many obstacles and challenges on their journey to reach and fertilize an ovum. Choice A is incorrect because the average count of sperm in an ejaculate is typically in the millions, not billions. Choice B is incorrect as sperm do not find the ovum by following the current of fluid; they navigate using other mechanisms. Choice D is incorrect because while some sperm may move randomly in the vagina, the ones that approach the ovum do so through a more purposeful and directed movement.