Which of the following allows a limited range of immune cells to detect and respond rapidly to a wide range of pathogens that share common structures?
A. Pattern recognition receptors (PRRs)
B. Cytokines
C. Chemokines
D. T cells .
Pattern recognition receptors (PRRs) are a class of receptors that can directly recognize the specific molecular structures on the surface of pathogens.
PRRs play a crucial role in the proper function of the innate immune system and are germline-encoded host sensors, which detect molecules typical for the pathogens.
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Choice B is incorrect because cytokines are not receptors but rather signaling molecules that regulate immunity.
Choice C is incorrect because chemokines are not receptors but rather signaling molecules that attract immune cells to sites of infection.
Choice D is incorrect because T cells are not receptors but rather white blood cells that assist B cells or directly kill infected cells.
Therefore, the Correct Answer is A.
More Questions on TEAS 7 Science
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Q #1: What is the organelle that encapsulates the contents of the cell and plays a vital role in regulating the movement of substances in and out of the cell?.
A. Ribosome
B. Nucleus
C. Mitochondria
D. Plasma membrane.
Answer Explanation
The plasma membrane is the organelle that encapsulates the contents of the cell and plays a vital role in regulating the movement of substances in and out of the cell.
It is a selectively permeable barrier that separates the internal environment of the cell from the external environment.
Choice A is incorrect because ribosomes are organelles involved in protein synthesis, not in regulating the movement of substances in and out of the cell.
Choice B is incorrect because the nucleus is an organelle that contains the cell’s genetic material, not in regulating the movement of substances in and out of the cell.
Choice C is incorrect because mitochondria are organelles involved in energy production, not in regulating the movement of substances in and out of the cell.
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Q #2: What is the relationship between atomic mass and mass number?
A. They are the same.
B. Atomic mass is always greater than mass number.
C. Atomic mass and mass number are not related.
D. Atomic mass is very close to mass number but with some deviation in the decimal places.
Answer Explanation
Atomic mass is very close to mass number but with some deviation in the decimal places.
Atomic mass is also known as atomic weight and is the weighted average mass of an atom of an element based on the relative natural abundance of that element’s isotopes.
The mass number, on the other hand, is a count of the total number of protons and neutrons in an atom’s nucleus.
Choice A is incorrect because atomic mass and mass number do not mean the same thing.
Choice B is incorrect because atomic mass is not always greater than mass number.
Choice C is incorrect because atomic mass and mass number are related.
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Q #3: Why is water sometimes called the "universal solvent"?.
A. Because water dissolves all solutes equally well.
B. Because water is a nonpolar solvent.
C. Because water is good at dissolving ions and polar molecules.
D. Because water is poor at dissolving nonpolar molecules.
Answer Explanation
Water is sometimes called the “universal solvent” because it dissolves more substances than any other liquid.
This is due to its polarity and ability to form hydrogen bonds, which allows it to dissolve ions and polar molecules.
Choice A) Because water dissolves all solutes equally well is incorrect because water does not dissolve all solutes equally well.
Choice B) Because water is a nonpolar solvent is incorrect because water is a polar solvent.
Choice D) Because water is poor at dissolving nonpolar molecules is incorrect because it does not explain why water is called the “universal solvent”.
