Nursing Elites

1. Which type of cell is responsible for carrying oxygen throughout the body?

• A. Nerve cell
• B. Muscle cell
• C. Skin cell
• D. Red blood cell

Correct answer: D

Rationale: The correct answer is D: Red blood cell. Red blood cells, also known as erythrocytes, are specifically designed to carry oxygen throughout the body. They contain hemoglobin, a protein that binds to oxygen in the lungs and transports it to tissues and organs in the body. Nerve cells, muscle cells, and skin cells do not have the specialized function of carrying oxygen like red blood cells do. Nerve cells transmit electrical signals, muscle cells are involved in movement, and skin cells provide a protective barrier and regulate body temperature. Therefore, choices A, B, and C are incorrect in the context of carrying oxygen throughout the body.

2. Which valve prevents blood from entering the left atrium when the ventricles contract?

• A. Pulmonary valve
• B. Tricuspid valve
• C. Mitral valve
• D. Aortic valve

Correct answer: C

Rationale: The correct answer is the mitral valve, also known as the bicuspid valve. The mitral valve prevents blood from flowing back into the left atrium during ventricular contraction. The tricuspid valve is located between the right atrium and right ventricle, the pulmonary valve is between the right ventricle and the pulmonary artery, and the aortic valve is situated between the left ventricle and the aorta. Therefore, choices A, B, and D are incorrect as they are not related to preventing blood from entering the left atrium during ventricular contraction.

3. What happens to the potential energy of an object when it is lifted higher above the ground?

• A. Potential energy decreases
• B. Potential energy remains the same
• C. Potential energy increases
• D. Potential energy becomes zero

Correct answer: C

Rationale: When an object is lifted higher above the ground, its potential energy increases. This is because the higher the object is lifted, the greater its potential energy due to the increased distance from the ground. The formula for gravitational potential energy is PE = mgh, where m is the mass of the object, g is the acceleration due to gravity, and h is the height above the reference point. Therefore, as the height (h) increases, the potential energy (PE) also increases, making choice C the correct answer. Choices A, B, and D are incorrect because when an object is lifted higher, it gains potential energy rather than losing it, keeping it the same, or becoming zero. Thus, the correct answer is that the potential energy of an object increases when it is lifted higher above the ground.

4. When ethanol (Câ‚‚Hâ‚…OH) reacts with sodium metal (Na), what is the product?

• A. Ethene (Câ‚‚Hâ‚„)
• B. Sodium ethoxide (Câ‚‚Hâ‚…ONa)
• C. Ethane (Câ‚‚H₆)
• D. Sodium acetate (CH₃COONa)

Correct answer: B

Rationale: When ethanol (C₂H₅OH) reacts with sodium metal (Na), the product formed is Sodium ethoxide (C₂H₅ONa). This reaction is a classic example of a metal displacing hydrogen in an alcohol to form an alkoxide. In this specific case, sodium replaces the hydrogen in ethanol, resulting in the formation of sodium ethoxide. Choice A, Ethene (C₂H₄), is incorrect as it is a different compound formed from the dehydration of ethanol, not its reaction with sodium. Choice C, Ethane (C₂H₆), is incorrect as it is a saturated hydrocarbon, not the product of the reaction of ethanol with sodium metal. Choice D, Sodium acetate (CH₃COONa), is incorrect as it involves acetic acid, not ethanol, reacting with sodium to form the salt sodium acetate.

5. Which of the following is a type of white blood cell that plays a key role in adaptive immunity by seeking out, attacking, and destroying targeted pathogens?

• A. memory B cells
• B. neutrophils
• C. antibodies
• D. cytotoxic T cells

Correct answer: D

Rationale: The correct answer is cytotoxic T cells. Cytotoxic T cells are a type of white blood cell that is crucial in adaptive immunity. They are specialized in recognizing and destroying infected or abnormal cells in the body. Neutrophils are primarily involved in innate immunity, providing rapid response to infections. Antibodies are proteins produced by B cells and are essential in specific immune responses, but they do not directly attack pathogens. Memory B cells are part of the adaptive immune response, responsible for mounting a quicker and stronger response upon re-exposure to a pathogen. However, they do not directly seek out and destroy pathogens like cytotoxic T cells do.

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