Nursing Elites

1. Melanin, the pigment responsible for skin color, is produced by

• A. Keratinocytes (These cells produce keratin)
• B. Melanocytes
• C. Sebocytes (These cells produce sebum)
• D. Langerhans cells (These cells are part of the immune system)

Correct answer: B

Rationale: The correct answer is B: Melanocytes. Melanin, the pigment responsible for skin color, is produced by melanocytes, which are specialized cells located in the skin's epidermis. Melanocytes transfer melanin to keratinocytes, the predominant cell type in the epidermis, where it provides protection against UV radiation. Sebocytes produce sebum, an oily substance that helps moisturize the skin and hair. Langerhans cells are a type of immune cell that play a role in the skin's immune response. Therefore, the correct answer is B as melanocytes are specifically responsible for producing melanin.

2. A prism separates white light into its constituent spectral components because:

• A. It absorbs certain colors
• B. Different colors experience varying speeds within the prism
• C. It bends all colors with the same magnitude
• D. It reflects specific colors

Correct answer: B

Rationale: The correct answer is B because different colors experience varying speeds when passing through a prism due to their differing wavelengths. This causes them to refract at different angles, resulting in the separation of white light into its constituent spectral components. The phenomenon of dispersion occurs as a result of this wavelength-dependent refraction, allowing us to see the full spectrum of colors. Absorbing certain colors (option A) or reflecting specific colors (option D) would not explain how a prism separates white light. Additionally, if a prism were to bend all colors with the same magnitude (option C), it would not result in the distinct separation of colors that we observe.

3. Which structure in the respiratory system serves as a passageway for both air and food, with a flap-like structure that prevents food from entering the trachea during swallowing?

• A. Larynx
• B. Pharynx
• C. Trachea
• D. Bronchi

Correct answer: B

Rationale: The correct answer is B: Pharynx. The pharynx is a structure in the respiratory system that serves as a passageway for both air and food. It has a flap-like structure called the epiglottis, which prevents food from entering the trachea during swallowing. The larynx is commonly known as the voice box and is responsible for sound production. The trachea is a tube that carries air to and from the lungs, and the bronchi are the two main branches that lead from the trachea to the lungs. Therefore, the pharynx is the correct answer as it specifically fits the description provided in the question.

4. The fundamental units of structure and function in all living organisms, including humans, are termed:

• A. Muscles
• B. Organs
• C. Tissues
• D. Cells

Correct answer: D

Rationale: The correct answer is D: Cells. Cells are the fundamental units of structure and function in all living organisms, including humans. They are the building blocks of life, performing various functions necessary for an organism to survive and thrive. Muscles (A) are composed of muscle tissue, which is made up of muscle cells. Organs (B) are structures made up of different types of tissues working together. Tissues (C) are groups of cells that work together to perform specific functions within an organism. However, cells are the smallest unit of life and are responsible for carrying out all the essential processes needed for an organism to function.

5. What is the name for the tiny particles that make up atoms?

• A. Protons
• B. Electrons
• C. Neutrons
• D. Subatomic particles

Correct answer: D

Rationale: Protons, neutrons, and electrons are all subatomic particles that make up atoms.

6. A ball is thrown upwards. At the peak of its trajectory, which of the following forces is acting on the ball?

• A. Gravity only
• B. Gravity and air resistance only
• C. Neither gravity nor air resistance
• D. All of the above

Correct answer: C

Rationale: At the peak of its trajectory, the ball has momentarily stopped moving upwards and has not yet started to fall back down. Therefore, there is no longer a net force acting on the ball at that instant. Gravity is acting downwards, but since the ball is not moving, the force of gravity is balanced by an equal and opposite force, resulting in a net force of zero. Similarly, air resistance only affects the ball when it is in motion, so at the peak where the ball momentarily stops, there is no air resistance force. Therefore, at the peak of its trajectory, neither gravity nor air resistance is acting on the ball, making option C the correct answer.

Similar Questions