Nursing Elites

1. Which of the following is a characteristic of alkenes?

• A. They have a double bond between carbon atoms.
• B. They are saturated hydrocarbons.
• C. They contain only single bonds.
• D. They are derivatives of ammonia.

Correct answer: A

Rationale: Alkenes are hydrocarbons that contain at least one carbon-carbon double bond. This double bond is a key characteristic that distinguishes alkenes from other types of hydrocarbons. Option A correctly identifies this defining feature of alkenes, making it the correct answer. Choices B, C, and D are incorrect. Choice B is incorrect because alkenes are unsaturated hydrocarbons due to the presence of double bonds. Choice C is incorrect as alkenes do not contain only single bonds; they have at least one double bond. Choice D is incorrect because alkenes are not derivatives of ammonia; they are a distinct class of organic compounds with carbon-carbon double bonds.

2. What is the product of translation from an RNA template?

• A. DNA
• B. Lipid
• C. Polypeptide
• D. Carbohydrate

Correct answer: C

Rationale: Translation is the process by which the genetic information carried by mRNA is decoded to synthesize a polypeptide chain. This essential process occurs at the ribosomes within the cell. The product of translation from an RNA template is a polypeptide, not DNA, lipid, or carbohydrate. DNA is involved in transcription, lipids are not directly produced in translation, and carbohydrates are not synthesized through translation. Therefore, the correct product resulting from translation from an RNA template is a polypeptide, making choice C, 'Polypeptide,' the correct answer.

3. How many chromosomes must a normal human sperm cell contain?

• A. An X chromosome.
• B. A Y chromosome.
• C. 23 chromosomes.
• D. Both an X and Y chromosome.

Correct answer: C

Rationale: A normal human sperm cell contains a total of 23 chromosomes, half the number found in a typical human cell which has 46 chromosomes. This includes 22 autosomes and one sex chromosome, which can be either an X or a Y chromosome. Therefore, the correct answer is that a normal human sperm cell must contain 23 chromosomes. Choices A and B are incorrect because a single sex chromosome alone does not represent the total number of chromosomes in a sperm cell. Choice D is incorrect because a sperm cell carries only one sex chromosome, either X or Y, not both.

4. When calcium chloride (CaCl2) dissolves in water, it separates into its ions (Ca2+ and Cl-). This is an example of:

• A. Chemical change
• B. Physical change
• C. Precipitation
• D. Neutralization

Correct answer: B

Rationale: When calcium chloride dissolves in water, it separates into its ions without forming a new substance, which is characteristic of a physical change. A physical change involves alterations in the substance's physical properties without changing its chemical composition. In this scenario, the chemical formula of calcium chloride remains unchanged, and only its physical state changes by creating ions in the solution. Therefore, the dissolution of calcium chloride in water is an example of a physical change. Choice A, 'Chemical change,' is incorrect because no new substances are formed during the dissolution process. Choice C, 'Precipitation,' is incorrect as precipitation involves the formation of an insoluble solid when two solutions react. Choice D, 'Neutralization,' is incorrect as it refers to a reaction between an acid and a base to form salt and water, which is not the case in the given scenario.

5. What is the function of the epiglottis?

• A. Produces saliva
• B. Senses taste
• C. Prevents food from entering the windpipe
• D. Filters blood

Correct answer: C

Rationale: The epiglottis is a flap of cartilage located at the base of the tongue that covers the opening of the windpipe (trachea) during swallowing to prevent food and liquids from entering the airway. This action ensures that food and liquids are directed to the esophagus and down into the stomach, rather than entering the respiratory system, which could lead to choking or aspiration pneumonia. Options A, B, and D are incorrect as they describe functions of other structures in the body that are not related to the role of the epiglottis.

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