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Which of the following substances is responsible for donating H+ ions to act as a buffer when blood pH rises?  

A. Carbon dioxide

B. Carbon monoxide

C. Carbonic acid

D. Oxygen

Answer Explanation:

Carbonic acid.

In the human body, maintaining the pH of the blood within a narrow range is critical for proper physiological functioning.

One of the buffering systems that helps to regulate blood pH involves the conversion of carbon dioxide (CO2) and water (H2O) into carbonic acid (H2CO3), which then dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3-).

 

Carbonic acid (H2CO3) is responsible for donating H+ ions to act as a buffer when blood pH rises.

When blood pH rises (becomes more alkaline), carbonic acid dissociates, and the H+ ions combine with bicarbonate ions to form more carbonic acid.

This helps to remove excess H+ ions from the blood and prevent the pH from rising too much.

Option A, carbon dioxide, is involved in the buffering system through its conversion to carbonic acid.

However, it does not directly donate H+ ions to act as a buffer when blood pH rises.

Option B, carbon monoxide, is a toxic gas that binds to hemoglobin in red blood cells, preventing them from carrying oxygen.

It is not involved in the buffering system and does not donate H+ ions.

Option D, oxygen, is carried by hemoglobin in red blood cells and is essential for respiration.

It is not involved in the buffering system and does not donate H+ ions.

Therefore, the Correct Answer is C.

More Questions on TEAS 7 Science

  • Q #1: Which of the following physiological responses is caused by the release of antidiuretic hormone?

    A. Increase in the concentration of calcium in the glomerulus.

    B. Increase in water reabsorption in the collecting duct

    C. Decrease in the concentration of calcium in the glomerulus.

    D. Decrease in water reabsorption in the collecting duct

    Answer Explanation

    Antidiuretic hormone (ADH), also known as vasopressin, is a hormone that helps regulate the amount of water in your body.

    It works to control the amount of water your kidneys reabsorb as they filter out waste from your blood.

     

    Choice A is not correct because an increase in the concentration of calcium in the glomerulus is not a physiological response caused by the release of antidiuretic hormone.

    Choice C is not correct because a decrease in the concentration of calcium in the glomerulus is not a physiological response caused by the release of antidiuretic hormone.

    Choice D is not correct because a decrease in water reabsorption in the collecting duct is not a physiological response caused by the release of antidiuretic hormone.

     

  • Q #2: Which of the following is the number of protons in a lithium atom?

    A. 7

    B. 3

    C. 12

    D. 4

    Answer Explanation

    The atomic number of an element represents the number of protons in the nucleus of an atom of that element.

    Since lithium has an atomic number of 3, it has 3 protons in its nucleus.

     

    Choice A is not correct because 7 is the mass number of lithium, not the number of protons.

    Choice C is not correct because 12 is not the atomic number or mass number of lithium.

    Choice D is not correct because 4 is not the atomic number or mass number of lithium.

     

  • Q #3: Stimulus: 1of 1. A group of students performed an experiment to test terminal velocity, which is the greatest speed obtained by a falling object. The students dropped different numbers of coffee filters and measured the resulting terminal velocity. Which of the following conclusions is supported by the data in the following data table? #OF FILTERS MASS (g) TERMINAL VELOCITY (m/s) 1 1.01 1.74 2 1.99 2.48 3 3.02 3.04 4 4.0 3.50 5 5.01 3.80  

    A. Terminal velocity is when the force of gravity is equal to air resistance.

    B. Heavier objects take more time to reach terminal velocity.

    C. Heavier objects fall faster than lighter objects.

    D. The greater the number of filters, the smaller the terminal velocity.

    Answer Explanation

    Heavier objects fall faster than lighter objects.

    The data in the table shows that as the number of filters (and therefore the mass) increases, the terminal velocity also increases.

    This means that the heavier objects (with more filters) are falling faster than the lighter objects (with fewer filters).

    Choice A is not supported by the data in the table as much as it is true.

    Terminal velocity is indeed when the force of gravity is equal to air resistance, but this definition does not provide any information about the relationship between mass and terminal velocity.

    Choice B is also not supported by the data in the table.

    The data does not provide any information about the time it takes for an object to reach terminal velocity.

    Choice D is not supported by the data in the table.

    The data shows that as the number of filters increases, the terminal velocity also increases.

    This means that the greater the number of filters, the greater (not smaller) the terminal velocity.