Nursing Elites

1. What is a contraceptive method that uses hormones to prevent ovulation?

• A. Spermicide
• B. Barrier method (condom, diaphragm)
• C. Combined oral contraceptive pill
• D. Intrauterine device (IUD)

Correct answer: C

Rationale: The correct answer is the Combined oral contraceptive pill (C). This method contains hormones (estrogen and progestin) that prevent ovulation, making it an effective contraceptive. Spermicide (A) is a substance that kills sperm and does not use hormones to prevent ovulation. Barrier methods (B) like condoms and diaphragms physically block sperm but do not involve hormone-induced prevention of ovulation. Intrauterine devices (IUDs) (D) prevent pregnancy through different mechanisms, such as altering the uterine environment and preventing sperm from fertilizing the egg, not by hormone-induced prevention of ovulation.

2. Two objects with equal masses collide head-on, both initially moving at the same speed. After the collision, they stick together. What is their final velocity?

• A. Zero
• B. Half their initial velocity
• C. Their initial velocity
• D. Twice their initial velocity

Correct answer: C

Rationale: In an inelastic collision where two objects stick together after colliding, momentum is conserved. Since the two objects have equal masses and equal initial velocities but opposite directions, their momenta cancel out. Therefore, after the collision, the combined mass will move at the same speed as the initial velocity, but in the direction of one of the objects. Choice A ('Zero') is incorrect because momentum is conserved, and the objects must move after the collision. Choice B ('Half their initial velocity') is incorrect as the final velocity is the same as the initial velocity due to momentum conservation. Choice D ('Twice their initial velocity') is incorrect as the final velocity cannot be twice the initial velocity based on the conservation of momentum principle.

3. What is the stage of mitosis during which the nuclear envelope reforms?

• A. Prophase
• B. Metaphase
• C. Telophase
• D. Cytokinesis

Correct answer: C

Rationale: During telophase, the nuclear envelope reforms around the separated sister chromatids at opposite poles of the cell. This stage marks the reversal of the processes that occurred during prophase, where the nuclear envelope breaks down. Metaphase is characterized by the alignment of chromosomes along the metaphase plate in the cell's center. Cytokinesis is the final step of cell division involving cytoplasmic division to form two daughter cells, but it does not involve the reformation of the nuclear envelope. Therefore, choice C (Telophase) is the correct answer as it specifically involves the reformation of the nuclear envelope, distinguishing it from the other stages of mitosis.

4. Which of the following meninges is a thin membrane containing numerous nerves and blood vessels that supply nourishment to the underlying brain cells and spinal cord?

• A. Arachnoid mater
• B. Dura mater
• C. Periosteum
• D. Pia mater

Correct answer: D

Rationale: The pia mater is the correct answer. It is a thin, innermost layer of the meninges that contains numerous nerves and blood vessels, providing nourishment to the underlying brain cells and spinal cord. The arachnoid mater (Choice A) is the middle layer of the meninges and does not contain as many nerves and blood vessels as the pia mater. The dura mater (Choice B) is the tough, outermost layer of the meninges and is not responsible for supplying nourishment. The periosteum (Choice C) is a connective tissue membrane covering bones, not part of the meninges.

5. Which blood type is considered a universal donor?

• A. A
• B. B
• C. AB
• D. O

Correct answer: D

Rationale: Blood type O is considered the universal donor because individuals with type O blood can donate red blood cells to individuals with any ABO blood type (A, B, AB, or O) without causing an adverse reaction. Type O blood lacks A or B antigens on the surface of red blood cells, minimizing the risk of an immune response when transfused into individuals with different blood types. Therefore, type O blood is in high demand for blood transfusions in emergency situations when the recipient's blood type is unknown or when there is a shortage of specific blood types. Choices A, B, and AB are not considered universal donors. Individuals with blood types A, B, or AB can only donate to individuals with compatible blood types to avoid adverse reactions since they have A and/or B antigens on the surface of their red blood cells, making them incompatible with all blood types.

Similar Questions