Nursing Elites

1. An atom has 17 protons, 20 neutrons, and 17 electrons. What is its mass, in amu?

• A. 17
• B. 20
• C. 37
• D. 54

Correct answer: C

Rationale: The atomic mass of an atom is the sum of the protons and neutrons in its nucleus. In this case, the atom has 17 protons and 20 neutrons, totaling 37 particles in the nucleus. Electrons are not considered in the atomic mass calculation as their mass is negligible compared to protons and neutrons. Therefore, the mass of the atom in atomic mass units (amu) is 37.

2. What is the function of ribosomal RNA (rRNA)?

• A. Carries amino acids to the ribosomes
• B. Reads the genetic code on mRNA
• C. Forms the structural framework of ribosomes
• D. Controls the rate of protein synthesis

Correct answer: C

Rationale: Ribosomal RNA (rRNA) plays a crucial role in forming the structural framework of ribosomes. Ribosomes are the cellular organelles responsible for protein synthesis and consist of both protein and rRNA components. The primary function of rRNA is to provide the structural support necessary for ribosomes to function properly. This structural framework allows the ribosome to interact with messenger RNA (mRNA) and transfer RNA (tRNA) during translation, where genetic information encoded in mRNA is used to assemble proteins from amino acids. Therefore, rRNA's main role is in contributing to the structure and function of ribosomes, rather than directly carrying amino acids, reading the genetic code, or controlling the rate of protein synthesis. Choices A, B, and D are incorrect because rRNA does not carry amino acids to the ribosomes (tRNA does this), read the genetic code (this is the role of ribosomes and tRNA), or control the rate of protein synthesis (this is regulated by various factors but not directly by rRNA).

3. Where does the maturation of T-cells and the production of T-cell receptors occur?

• A. Thymus
• B. Spleen
• C. Lymph nodes
• D. Bone marrow

Correct answer: A

Rationale: The correct answer is the Thymus. T-cells mature and develop their receptors in the thymus gland, making it a vital organ for the immune system. The thymus provides the necessary environment for T-cells to differentiate and acquire their specific receptors and functions, which are essential for their role in the adaptive immune response. The spleen, lymph nodes, and bone marrow are all important components of the immune system, but they do not primarily serve as sites for T-cell maturation and T-cell receptor production.

4. What happens to the gravitational potential energy of an object as it falls freely?

• A. It decreases
• B. It increases
• C. It remains constant
• D. It becomes zero

Correct answer: A

Rationale: The correct answer is A: 'It decreases.' When an object falls freely, its height decreases, resulting in a decrease in gravitational potential energy. The potential energy is converted into kinetic energy as the object accelerates due to gravity. This conversion process continues until the object reaches the ground or its lowest point, where the gravitational potential energy is minimal or zero. Choice B is incorrect because gravitational potential energy decreases, not increases, during free fall. Choice C is incorrect as gravitational potential energy changes due to the change in height. Choice D is incorrect as the gravitational potential energy does not instantly become zero but decreases gradually as the object falls.

5. What is the bottom number in a blood pressure reading?

• A. Diastolic pressure
• B. Systolic pressure
• C. Pulse rate
• D. Mean arterial pressure

Correct answer: A

Rationale: The correct answer is A: Diastolic pressure. The bottom number in a blood pressure reading represents the diastolic pressure, which indicates the lowest pressure in the arteries when the heart is resting between beats. This value is important in understanding the overall health of the cardiovascular system. Choice B, Systolic pressure, is the top number in a blood pressure reading and represents the pressure in the arteries when the heart is contracting. Choice C, Pulse rate, refers to the number of times the heart beats in a minute. Choice D, Mean arterial pressure, is a calculated value using both systolic and diastolic pressures to provide an average pressure in the arteries during a cardiac cycle, but it is not the bottom number in a blood pressure reading.

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