Nursing Elites

1. How does the human eye focus light?

• A. Cornea
• B. Iris
• C. Lens
• D. Retina

Correct answer: C

Rationale: The human eye focuses light by adjusting the shape of its lens. The lens changes shape to allow the eye to focus on objects at different distances, a process known as accommodation. The cornea is the transparent outer covering of the eye that helps to focus light but does not change shape like the lens. The iris controls the size of the pupil to regulate the amount of light entering the eye. The retina is the light-sensitive layer at the back of the eye that receives and processes images but does not adjust the focus of light.

2. What is the difference between a sensory neuron and a motor neuron?

• A. Sensory neurons carry signals from sensory receptors towards the central nervous system, while motor neurons carry signals away from the central nervous system to muscles and glands.
• B. Sensory neurons control voluntary muscles, while motor neurons control involuntary muscles.
• C. Sensory neurons are located in the peripheral nervous system, while motor neurons are located in the central nervous system.
• D. Sensory neurons detect light, while motor neurons detect sound.

Correct answer: A

Rationale: Sensory neurons are responsible for carrying signals from sensory receptors towards the central nervous system (brain and spinal cord), allowing the brain to receive information about the external environment. On the other hand, motor neurons carry signals away from the central nervous system to muscles and glands, enabling the brain to control voluntary and involuntary movements. Choice B is incorrect because sensory neurons do not control muscles, and motor neurons control both voluntary and involuntary muscles. Choice C is incorrect as sensory neurons are located in the peripheral nervous system, while motor neurons are located in the central nervous system. Choice D is incorrect because sensory neurons detect various stimuli such as touch, taste, smell, and sound, while motor neurons are not involved in detecting sensory stimuli.

3. What is the process of breaking down glucose into pyruvate called?

• A. Glycolysis
• B. Gluconeogenesis
• C. Krebs cycle
• D. Oxidative phosphorylation

Correct answer: A

Rationale: A) Glycolysis is the process of breaking down glucose into pyruvate. This occurs in the cytoplasm of cells and is the first step in cellular respiration. B) Gluconeogenesis is the process of synthesizing glucose from non-carbohydrate sources, such as amino acids or glycerol, and is the opposite of glycolysis. C) The Krebs cycle, also known as the citric acid cycle, is a series of chemical reactions that occur in the mitochondria and is involved in the oxidation of acetyl-CoA to produce ATP and other energy carriers. D) Oxidative phosphorylation is the final stage of cellular respiration where ATP is produced through the transfer of electrons in the electron transport chain.

4. Which state of matter has both a definite volume and a definite shape?

• A. Solid
• B. Liquid
• C. Gas
• D. Plasma

Correct answer: A

Rationale: The correct answer is 'Solid.' Solids have both a definite volume and a definite shape because the particles are closely packed together and vibrate in fixed positions. This close arrangement of particles allows solids to maintain their shape and volume, unlike liquids and gases which do not have a definite shape. Liquids take the shape of their container but have a definite volume. Gases, on the other hand, do not have a definite shape or volume as they expand to fill the space available to them. Plasma is a high-energy state of matter where atoms are stripped of their electrons and is not characterized by definite shape or volume.

5. Which of the following is a strong acid?

• A. Acetic acid (CH₃COOH)
• B. Hydrochloric acid (HCl)
• C. Citric acid
• D. Carbonic acid (H₂CO₃)

Correct answer: B

Rationale: Hydrochloric acid (HCl) is a strong acid because it completely ionizes in water to produce hydrogen ions, leading to a high concentration of H⁺ ions in solution. This characteristic makes it a strong acid. Acetic acid (CH₃COOH), citric acid, and carbonic acid (H₂CO₃) are weak acids as they only partially ionize in water, resulting in a lower concentration of H⁺ ions compared to strong acids. Therefore, hydrochloric acid is the correct choice as a strong acid.

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