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. What do positive feedback mechanisms do?

A. Cause long-term changes.
B. Move conditions away from the normal state.
C. Bring conditions back to the normal state.
D. Usually produce stable conditions.

Correct answer: B

Rationale: Positive feedback mechanisms amplify or increase changes in a system, moving conditions away from the normal state. This makes choice B the correct answer. Choice A is incorrect as positive feedback does not cause long-term changes but rather accelerates deviations from the norm. Choice C is incorrect because positive feedback does not bring conditions back to normal; instead, it amplifies deviations. Choice D is incorrect as positive feedback does not usually lead to stable conditions but rather to further deviations from the normal state.

3. Is a cell the basic unit of structure and function of an organism?

A. True
B. False
C. Not Sure
D. None of the above

Correct answer: A

Rationale: The correct answer is A: True. A cell is indeed the basic unit of structure and function of an organism. Cells are the smallest independently functioning unit in the structure of an organism and carry out vital functions necessary for life. Choice B, False, is incorrect because cells are universally recognized as the fundamental unit of life. Choice C, Not Sure, is incorrect as the role of a cell as the basic unit of an organism's structure and function is a well-established scientific fact. Choice D, None of the above, is incorrect as the statement provided in the question is true.

4. When does cell death first occur?

A. At age 60.
B. At age 50.
C. At puberty.
D. In the fetus.

Correct answer: D

Rationale: Cell death, also known as apoptosis, first occurs during fetal development when specific cells are programmed to die. This process is essential for shaping and organizing tissues and organs. Choices A, B, and C are incorrect because cell death begins much earlier, during fetal development, rather than later in life or at puberty. Understanding the timing of cell death in different stages of life is crucial in developmental biology.

5. What is the function of the gallbladder?

A. Filters all of the blood in the body and breaks down poisonous substances, such as alcohol and drugs
B. Make enzymes
C. Store and concentrate bile, a fluid produced by the liver that helps with fat digestion
D. Helps to further digest food

Correct answer: C

Rationale: The correct answer is C: Store and concentrate bile, a fluid produced by the liver that helps with fat digestion. The gallbladder stores bile produced by the liver and releases it to aid in the digestion of fats. Choice A is incorrect as the liver, not the gallbladder, filters blood and detoxifies harmful substances. Choice B is incorrect because the production of enzymes primarily occurs in the pancreas, not the gallbladder. Choice D is incorrect as the gallbladder's main role is not to further digest food but to store and release bile.