Nursing Elites

1. A water molecule contains two types of atoms that are covalently bonded. Which of the following makes up a water molecule?

• A. One hydrogen atom and one oxygen atom
• B. One hydrogen atom and two oxygen atoms
• C. Two hydrogen atoms and two oxygen atoms
• D. Two hydrogen atoms and one oxygen atom

Correct answer: D

Rationale: The correct answer is D: Two hydrogen atoms and one oxygen atom. A water molecule consists of two hydrogen atoms covalently bonded to one oxygen atom. This forms a stable structure known as H2O. Choice A is incorrect as water molecule contains two hydrogen atoms. Choices B and C are incorrect as they do not reflect the correct composition of a water molecule.

2. Which cell structure is responsible for efficiently packaging DNA into a small volume to fit into the nucleus of a cell and protect the DNA structure and sequence?

• A. Golgi apparatus
• B. Chromatin
• C. Smooth endoplasmic reticulum
• D. Mitochondria

Correct answer: B

Rationale: The correct answer is B: Chromatin. Chromatin is responsible for packaging DNA into a more compact, dense shape to fit into the nucleus of a cell. This compact packaging helps protect the DNA structure and regulate gene expression. The Golgi apparatus is involved in modifying, sorting, and packaging proteins. The smooth endoplasmic reticulum is involved in lipid metabolism and detoxification. Mitochondria are known as the powerhouse of the cell, producing energy in the form of ATP.

3. What function does cholesterol, a phospholipid, serve within the cell membrane?

• A. It builds up fats to make the structure more flexible
• B. It allows protein channels to form
• C. It makes the structure very rigid and impermeable
• D. It stabilizes the membrane structure

Correct answer: D

Rationale: Cholesterol helps to maintain the fluidity and stability of the cell membrane by fitting between the phospholipid molecules. Choice A is incorrect because cholesterol does not build up fats in the cell membrane. Choice B is incorrect as protein channels are formed by proteins, not cholesterol. Choice C is incorrect as cholesterol actually helps regulate the fluidity of the membrane, making it less rigid and more permeable.

4. In the hierarchy of biology, cells combine to form which of the following?

• A. Macromolecules
• B. Molecules
• C. Tissues
• D. Organelles

Correct answer: C

Rationale: In the hierarchy of biology, cells combine to form tissues. Tissues are groups of cells that work together to perform specific functions. This is a fundamental level of organization above individual cells but below organs and organ systems. Macromolecules and molecules are smaller components that make up cells, not what cells combine to form. Organelles are structures within cells that perform specific functions and do not result from the combination of cells.

5. What is the most important function of carbohydrates?

• A. Store and provide energy for the body
• B. Create amino acids
• C. Maintain body temperature
• D. Insulate body organs against shock

Correct answer: A

Rationale: The most important function of carbohydrates is to store and provide energy for the body through metabolic processes. Carbohydrates are broken down into glucose, which is used as the primary source of energy for various cellular functions. Choice B is incorrect because amino acids are the building blocks of proteins, not directly created by carbohydrates. Choice C is incorrect as the regulation of body temperature is primarily controlled by mechanisms such as sweating and shivering, not carbohydrates. Choice D is incorrect as insulation of body organs against shock is mainly provided by adipose tissue, not carbohydrates.

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