Nursing Elites

1. What are substances that stimulate adaptive immunity called?

• A. Peptides
• B. Phagocytes
• C. Prions
• D. Platelets

Correct answer: A

Rationale: Substances that stimulate adaptive immunity are called peptides. Peptides are short chains of amino acids that play a crucial role in activating the immune response by interacting with immune cells such as T cells and B cells. Peptides are important in antigen presentation and recognition, leading to the development of specific immune responses against pathogens. Choice B, phagocytes, are cells that engulf and digest pathogens but are not substances that stimulate adaptive immunity. Choice C, prions, are infectious agents made of misfolded proteins and are not related to stimulating adaptive immunity. Choice D, platelets, are cell fragments involved in blood clotting and have no direct role in stimulating adaptive immunity.

2. Which property of a substance refers to its ability to undergo a chemical change and form new substances?

• A. Density
• B. Mass
• C. Reactivity
• D. Volume

Correct answer: C

Rationale: Reactivity is the property of a substance that describes its ability to undergo a chemical change and form new substances through chemical reactions. Density, mass, and volume are physical properties of a substance and do not directly relate to its ability to undergo chemical changes. Density is the mass of a substance per unit volume, mass is the amount of matter present, and volume is the amount of space occupied by the substance. Reactivity specifically deals with how likely a substance is to engage in chemical reactions. Therefore, the correct answer is C - Reactivity.

3. Which type of chemical reaction produces a salt?

• A. An oxidation reaction
• B. A neutralization reaction
• C. A synthesis reaction
• D. A decomposition reaction

Correct answer: B

Rationale: The correct answer is B, a neutralization reaction. In a neutralization reaction, an acid and a base react to produce a salt and water. This process involves the combination of H+ ions from the acid and OH- ions from the base to form water, while the remaining ions combine to form a salt. Therefore, a neutralization reaction is the specific type of chemical reaction that produces a salt. Choices A, C, and D are incorrect. An oxidation reaction involves the loss of electrons, a synthesis reaction involves the formation of a compound from simpler substances, and a decomposition reaction involves the breakdown of a compound into simpler substances. None of these reactions directly lead to the production of a salt, making them incorrect choices in this context.

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

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

Correct answer: B

Rationale: Myosin is the protein complex responsible for the thick filament in the sarcomere. It interacts with actin, another protein in the sarcomere, to generate the sliding movement that results in muscle contraction. Actin is a thin filament protein that interacts with myosin to create the sliding filament mechanism. Tropomyosin and troponin are regulatory proteins that regulate muscle contraction by controlling the interaction between actin and myosin, rather than directly being responsible for the thick filament.

5. 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.

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