which of the following types of cells is primarily responsible for the destruction of old cells and invasive micro organisms

ATI RN

ATI Anatomy and Physiology

1. Which of the following types of cells is primarily responsible for the destruction of old cells and invasive micro-organisms?

A. Basophils
B. Eosinophils
C. B-cells
D. Macrophages

Correct answer: D

Rationale: Macrophages are a type of white blood cell that plays a crucial role in the immune system by engulfing and digesting cellular debris, foreign substances, microbes, cancer cells, and old or damaged cells. Basophils are primarily involved in allergic reactions and parasitic infections, eosinophils combat multicellular parasites and have a role in allergic reactions, and B-cells are responsible for producing antibodies. Therefore, the correct answer is macrophages as they are specialized in phagocytosis and removal of unwanted cells and microorganisms.

2. Living organisms use oxygen to __________________.

A. reduce heat production
B. accept electrons for cellular metabolism
C. release energy stored in the molecules of food
D. remove metabolic wastes

Correct answer: C

Rationale: The correct answer is C. Living organisms use oxygen to release energy stored in the molecules of food through a process called cellular respiration. This process involves breaking down glucose molecules in the presence of oxygen to produce energy in the form of ATP. Choice A is incorrect because oxygen does not directly reduce heat production in organisms. Choice B is incorrect because oxygen is involved in accepting electrons rather than donating them in cellular metabolism. Choice D is incorrect because the removal of metabolic wastes is not the primary role of oxygen in living organisms.

3. The maintenance of a steady body temperature in the face of fluctuating environmental conditions illustrates homeostasis.

A. TRUE
B. FALSE
C. Not Sure
D. None of the above

Correct answer: A

Rationale: The correct answer is True. Homeostasis is the body's ability to maintain a stable internal environment despite external changes. In this case, the maintenance of a steady body temperature despite fluctuations in environmental conditions is a clear example of homeostasis. The body regulates temperature through processes like sweating when it's hot and shivering when it's cold. Choices B, C, and D are incorrect because the statement provided does indeed illustrate the concept of homeostasis, making them inaccurate.

4. What is homeostasis?

A. The inability to keep body weight within normal limits.
B. Room temperature decreasing because a window is open.
C. Ingestion of more food than needed.
D. The tendency of the body to maintain a stable internal environment.

Correct answer: D

Rationale: The correct answer is D: Homeostasis refers to the body's ability to maintain a stable internal environment despite external changes. Choices A, B, and C are incorrect. Choice A describes obesity, choice B describes a specific scenario with room temperature, and choice C refers to overeating, which is not related to homeostasis.

5. What function is associated with the dermal layer of the skin?

A. Sensory perception
B. To provide support and structure to the skin
C. Protection from UV rays
D. Insulation

Correct answer: B

Rationale: The correct function associated with the dermal layer of the skin is to provide support and structure to the skin. The dermis is the thickest layer of the skin and is responsible for maintaining the skin's integrity and firmness. Choices A, C, and D are incorrect as sensory perception, protection from UV rays, and insulation are functions associated with other layers of the skin, such as the epidermis and subcutaneous tissue.