Nursing Elites

1. What is the primary function of the myelin sheath that surrounds some axons in the nervous system?

• A. To initiate nerve impulses
• B. To transmit sensory information
• C. To speed up the transmission of nerve impulses
• D. To connect neurons at synapses

Correct answer: C

Rationale: The primary function of the myelin sheath is to speed up the transmission of nerve impulses. The myelin sheath acts as an insulating layer around the axon, allowing for faster conduction of electrical impulses along the nerve fiber. This insulation prevents the electrical signal from dissipating or 'leaking' out, which helps in the rapid and efficient transmission of nerve impulses along the axon. Choice A is incorrect because the myelin sheath does not initiate nerve impulses; it helps in conducting them. Choice B is incorrect as the myelin sheath's main role is not in transmitting sensory information but rather in facilitating the transmission of nerve impulses. Choice D is incorrect because the myelin sheath's function is not to connect neurons at synapses; instead, it is primarily involved in enhancing the speed of nerve impulse transmission.

2. Where is the major site for nutrient absorption in the digestive system?

• A. Mouth
• B. Stomach
• C. Small intestine
• D. Large intestine

Correct answer: C

Rationale: The small intestine is recognized as the major site for nutrient absorption in the digestive system. It plays a crucial role in the digestion and absorption of nutrients from food. The small intestine's villi and microvilli provide a large surface area specialized for absorbing nutrients like carbohydrates, proteins, fats, vitamins, and minerals. This efficient absorption process is essential for supplying the body with the necessary nutrients for energy production, growth, and overall functioning. The mouth is primarily involved in the initial stages of digestion through mechanical and chemical breakdown of food. The stomach aids in further mechanical and chemical digestion but is not the primary site for nutrient absorption. The large intestine's main function is to absorb water and electrolytes, not nutrients.

3. What type of bond connects sugar and phosphate in DNA?

• A. Hydrogen
• B. Ionic
• C. Covalent
• D. Overt

Correct answer: C

Rationale: The correct answer is Covalent (C). In DNA, a covalent bond connects sugar and phosphate molecules. This bond involves the sharing of electron pairs between the atoms, providing stability to the DNA structure. Hydrogen bonds are important in DNA structure but are not the primary bond connecting sugar and phosphate. Ionic bonds involve the transfer of electrons, and 'overt' is not a term related to the bond connecting sugar and phosphate in DNA.

4. What do large intestines absorb?

• A. Water, sodium, and potassium ions
• B. Proteins and carbohydrates
• C. Water, vitamin K, and bile salts
• D. Vitamins A, D, E, K

Correct answer: C

Rationale: The correct answer is C. The large intestine absorbs water, vitamin K, bile salts, sodium, and chloride ions. It helps in maintaining the body's water and electrolyte balance, and also plays a role in absorbing certain vitamins and nutrients such as vitamin K. Choices A, B, and D are incorrect because proteins, carbohydrates, vitamins A, D, E, and K are primarily absorbed in the small intestine, not the large intestine.

5. Which type of cell division is responsible for growth and repair?

• A. Meiosis
• B. Mitosis
• C. Binary fission
• D. Osmosis

Correct answer: B

Rationale: Mitosis is the correct type of cell division responsible for growth and repair. During mitosis, a cell divides to produce two identical daughter cells, contributing to growth and tissue repair in multicellular organisms. Meiosis, on the other hand, is involved in the formation of gametes (sperm and egg cells) for sexual reproduction. Binary fission is a form of asexual reproduction in single-celled organisms, and osmosis is the movement of water molecules across a selectively permeable membrane. Therefore, choices A, C, and D are incorrect as they are not directly related to growth and repair in multicellular organisms.

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