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. What is the work done by a force of 20 N acting on an object that moves 5 meters in the direction of the force?

• A. 100 Joules (J)
• B. 25 Joules (J)
• C. 4 Joules (J)
• D. Work cannot be determined without knowing the object's mass.

Correct answer: A

Rationale: The work done is calculated using the formula: Work = Force x Distance x cos(theta), where theta is the angle between the force and the direction of motion. In this case, the force and the direction of motion are in the same direction, so cos(theta) = 1. Therefore, Work = 20 N x 5 m x 1 = 100 Joules. Since the force and distance are given and are in the same direction, the work done can be directly calculated without needing to know the object's mass. Choice A, 100 Joules, is the correct answer as calculated. Choice B and C are incorrect as they do not correspond to the correct calculation. Choice D is incorrect because knowing the object's mass is not necessary to calculate work in this scenario, as work is dependent on force, distance, and the angle between them, not mass.

3. What type of epithelium lines the inner surface of blood vessels?

• A. Simple squamous epithelium
• B. Simple columnar epithelium
• C. Stratified squamous epithelium
• D. Stratified columnar epithelium

Correct answer: A

Rationale: The correct answer is simple squamous epithelium (Choice A). The inner surface of blood vessels is lined by a single layer of flattened cells, known as simple squamous epithelium. This epithelium type is thin and allows for efficient diffusion and filtration, which is essential for the exchange of gases and nutrients across blood vessel walls. Simple columnar epithelium (Choice B) is typically found in the lining of the gastrointestinal tract and is responsible for absorption and secretion. Stratified squamous epithelium (Choice C) is commonly found in the skin, providing protection against mechanical stress. Stratified columnar epithelium (Choice D) is not a characteristic epithelium type found in the lining of blood vessels, as it is more commonly present in specific regions of the body like parts of the male urethra and the conjunctiva of the eye.

4. Which of the following structures is unique to eukaryotic cells?

• A. Cell walls
• B. Nuclei
• C. Cell membranes
• D. Vacuoles

Correct answer: B

Rationale: Nuclei are structures that are unique to eukaryotic cells. Prokaryotic cells lack a defined nucleus, and their genetic material floats freely in the cytoplasm. Eukaryotic cells have nuclei that house the genetic material in the form of chromosomes, separated from the cytoplasm by a nuclear membrane. This distinct organelle is a key feature that sets eukaryotic cells apart from prokaryotic cells. Cell walls (Choice A) are found in plant cells, fungi, and some prokaryotes but are not unique to eukaryotic cells. Cell membranes (Choice C) are present in both prokaryotic and eukaryotic cells, serving as a barrier that encloses the cell contents. Vacuoles (Choice D) are membrane-bound organelles found in both plant and animal cells, making them not unique to eukaryotic cells.

5. Adaptive radiation refers to the evolutionary process where:

• A. A single ancestral species diversifies into multiple descendant species due to ecological pressures in a heterogeneous environment.
• B. Two unrelated species evolve similar adaptations in response to similar environments, leading to convergent evolution.
• C. A population becomes increasingly well-adapted to its current environment through continued natural selection.
• D. The fossil record exhibits gaps or missing links in the evolutionary history of a lineage.

Correct answer: A

Rationale: - Adaptive radiation is a process where a single ancestral species diversifies into multiple descendant species to exploit different ecological niches within a heterogeneous environment. - This diversification occurs due to the different selective pressures present in various habitats, leading to the evolution of distinct traits and adaptations in different descendant species. - Option A accurately describes the process of adaptive radiation, where the initial species undergoes rapid speciation to occupy different ecological roles and adapt to diverse environmental conditions. - Options B, C, and D do not accurately describe adaptive radiation but refer to other evolutionary processes such as convergent evolution, natural selection, and gaps in the fossil record, respectively.

Similar Questions