Nursing Elites

1. What is the difference between a pure substance and a mixture?

• A. Pure substances have fixed composition, mixtures don't.
• B. Mixtures have fixed composition, pure substances don't
• C. Pure substances are always solids, mixtures can be any state
• D. Pure substances are always elements, mixtures are always compounds

Correct answer: A

Rationale: Rationale: - Pure substances have a definite and constant composition, meaning they are made up of only one type of atom or molecule. This composition does not vary. - Mixtures, on the other hand, are composed of two or more substances physically combined. The components of a mixture can be present in varying proportions, leading to a variable composition. - Option A correctly distinguishes between pure substances and mixtures based on the fixed composition of pure substances and the variable composition of mixtures.

2. Which of the following is an example of stabilizing selection?

• A. Selection that favors extreme traits in a population
• B. Selection that removes individuals with extreme traits
• C. Selection that maintains the current average trait in a population
• D. Selection that favors one specific trait over all others

Correct answer: C

Rationale: Rationale: - Stabilizing selection is a type of natural selection that favors the intermediate variants in a population, while selecting against the extreme traits. This results in the maintenance of the current average trait in the population. - Option A is incorrect because stabilizing selection does not favor extreme traits; instead, it favors the average trait. - Option B is incorrect because stabilizing selection does not remove individuals with extreme traits; it acts against extreme traits by favoring the intermediate variants. - Option D is incorrect because stabilizing selection does not favor one specific trait over all others; it favors the average trait by selecting against extreme traits.

3. Which vitamin deficiency can lead to kidney stones?

• A. Vitamin A
• B. Vitamin B12
• C. Vitamin D
• D. Vitamin K

Correct answer: D

Rationale: The correct answer is D, Vitamin K. Vitamin K plays a role in blood clotting and bone health. A deficiency in Vitamin K can lead to an increased risk of kidney stones due to the improper regulation of calcium in the body. Calcium can accumulate in the kidneys and form stones if not properly managed. Vitamin K deficiency can disrupt the balance of calcium in the body, contributing to the development of kidney stones. Therefore, it is important to ensure an adequate intake of Vitamin K to prevent kidney stone formation.

4. What property of a substance refers to its ability to be drawn into thin wires?

• A. Conductivity
• B. Ductility
• C. Viscosity
• D. Malleability

Correct answer: b

Rationale: Ductility refers to a substance's ability to be drawn into thin wires without breaking.

5. An IV drip delivers medication at a rate of 40 drops per minute. Each drop contains 0.05 milliliters of the medication. How many milliliters of medication are delivered in one hour?

• A. 12 milliliters
• B. 24 milliliters
• C. 60 milliliters
• D. 120 milliliters

Correct answer: B

Rationale: First convert minutes to hours (1 hour * 60 minutes). Then, multiply the number of drops per minute (40 drops/minute) by the volume per drop (0.05 ml/drop) and by the conversion factor (60 minutes/hour) to find the total volume delivered: 40 drops/minute * 0.05 ml/drop * 60 minutes/hour = 24 milliliters.

6. Which protein complex in the sarcomere is responsible for the thick filament?

• A. Actin
• B. Myosin
• C. Tropomyosin
• D. Troponin

Correct answer: B

Rationale: The correct answer is B: Myosin. In the sarcomere, the thick filament is composed of myosin protein. Myosin is responsible for the interaction with actin filaments during muscle contraction, forming cross-bridges that generate the force required for muscle movement. Actin (choice A) is a component of the thin filament in the sarcomere, while tropomyosin (choice C) and troponin (choice D) are regulatory proteins associated with muscle contraction but are not part of the thick filament. Understanding the specific components of the sarcomere is crucial for comprehending muscle contraction mechanisms.

Similar Questions