Nursing Elites

1. Which of the following situations represents work being done on an object?

• A. Pushing against a wall without moving it
• B. Carrying a heavy object without lifting it
• C. Lifting a box to place it on a shelf
• D. Holding a book stationary in your hand

Correct answer: C

Rationale: Work is defined as the product of the force applied to an object and the distance over which the force is applied. In the situation of lifting a box to place it on a shelf, work is being done on the object. This is because lifting the box involves applying a force over a distance (the height of the shelf). The force applied to lift the box results in work being done on the object by raising it against the force of gravity. Choices A, B, and D do not involve work being done on the object as they either do not involve movement against a force (A, D) or do not cover distance against a force (B).

2. Which transport mechanism uses vesicles to move materials out of the cell?

• A. Endocytosis
• B. Active transport
• C. Diffusion
• D. Exocytosis

Correct answer: D

Rationale: Exocytosis is the transport mechanism that uses vesicles to move materials out of the cell. Vesicles carry substances to the cell membrane, fuse with it, and release their contents outside the cell. This process is essential for secreting molecules such as hormones, enzymes, or neurotransmitters. Endocytosis, on the other hand, is the process of bringing materials into the cell by engulfing them in vesicles. Active transport involves the movement of molecules across a cell membrane against their concentration gradient, requiring energy. Diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration.

3. What is the name of the regulatory region in a gene that controls its expression?

• A. Exon
• B. Intron
• C. Promoter
• D. Enhancer

Correct answer: C

Rationale: A) Exon: Exons are the coding regions of a gene that are transcribed into mRNA and eventually translated into proteins. Exons do not regulate gene expression. B) Intron: Introns are non-coding regions of a gene that are removed during RNA processing and do not play a direct role in controlling gene expression. C) Promoter: The promoter is a regulatory region located at the beginning of a gene that initiates the process of transcription by binding transcription factors and RNA polymerase. It plays a crucial role in controlling gene expression. D) Enhancer: Enhancers are regulatory regions that can be located far from the gene they regulate and can increase the transcription of a gene. While enhancers are important for gene expression, the specific region that controls gene expression is the promoter. Therefore, the correct answer is C) Promoter, as it is the regulatory region in a gene that controls its expression by initiating transcription.

4. Which part of the digestive system is responsible for absorbing nutrients?

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

Correct answer: C

Rationale: The small intestine is the correct answer because it is the primary site for nutrient absorption in the digestive system. It contains specialized structures such as villi and microvilli that maximize the absorption of nutrients from digested food. The esophagus is responsible for transporting food from the mouth to the stomach; the stomach primarily aids in digestion by secreting enzymes and acids; and the large intestine mainly absorbs water and electrolytes from the remaining indigestible food matter. Therefore, the small intestine plays a crucial role in absorbing essential nutrients for the body's functions, making it the correct choice in this context.

5. The number of protons in an atom determines its:

• A. Mass number
• B. Atomic number
• C. Atomic weight
• D. Valence electron count

Correct answer: B

Rationale: The number of protons in an atom is known as the atomic number. The atomic number uniquely identifies an element and determines its position on the periodic table. It is a fundamental property of an element and directly influences its chemical behavior and interactions. The mass number, on the other hand, is the sum of protons and neutrons in the nucleus of an atom, not just protons. Atomic weight is the average mass of an element's isotopes considering their relative abundance, not solely based on the number of protons. Valence electron count refers to the number of electrons in the outermost energy level of an atom, influencing its ability to form bonds and participate in chemical reactions, but it is not determined by the number of protons in the atom.

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