Which of the following actions allows for repolarization of a neuron?
A. The inhibition of sodium and potassium pumps, stopping all ion movement into the neuron
B. The opening of sodium channels, allowing sodium to enter the neuron
C. The closing of both sodium and potassium channels to restrict movement of ions into and out of the neuron
D. The opening of potassium channels allowing potassium to leave the neuron
D. The opening of potassium channels allowing potassium to leave the neuron
The correct answer is d. The opening of potassium channels allowing potassium to leave the neuron. Repolarization of a neuron occurs after an action potential, when the neuron's membrane potential returns to its resting state. This is achieved by the opening of potassium channels, which allows potassium ions to flow out of the neuron. This movement of positively charged ions out of the neuron helps to restore the negative membrane potential.
A. The inhibition of sodium and potassium pumps would not allow for repolarization because these pumps are necessary for maintaining the resting membrane potential.
B. The opening of sodium channels would cause depolarization, not repolarization.
C. The closing of both sodium and potassium channels would restrict ion movement, but it would not allow for repolarization.
Therefore, the Correct Answer is D.
More Questions on TEAS 7 Science
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Q #1: If a mother's____________ cell contains mutated DNA, this mutation can be passed to her offspring. Which of the following options correctly completes the sentence above?
A. somatic
B. white blood
C. germ.
D. Stem
Answer Explanation
The correct answer is c. germ. If a mother's germ cell contains mutated DNA, this mutation can be passed to her offspring. Germ cells are the reproductive cells (eggs in females and sperm in males) that carry genetic information from one generation to the next.
a. Somatic cells are all the other cells in the body that are not germ cells. Mutations in somatic cells are not passed on to offspring.
b.White blood cells are a type of somatic cell that plays a role in the immune system.
d. Stem cells are undifferentiated cells that have the ability to develop into different types of cells in the
body.
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Q #2: Which of the following is a function of bone?
A. Storage of minerals
B. Detoxification of alcohol
C. Secretion of hormones
D. Production of otoliths
Answer Explanation
The correct answer is a. Storage of minerals. Bones serve as a storage site for minerals such as calcium and phosphorus. These minerals are essential for various bodily functions and can be released from the bones into the bloodstream when needed.
b. Detoxification of alcohol is not a function of bone. This process occurs primarily in the liver.
c. Secretion of hormones is not a function of bone. Hormones are produced and secreted by glands such as the pituitary gland, thyroid gland, and adrenal glands.
d. Production of otoliths is not a function of bone. Otoliths are small calcium carbonate structures found in the inner ear of fish and other vertebrates that help with balance and hearing.
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Q #3: Which of the following is correct regarding the pH scale?
A. A substance with a pH of 3 is two times more alkaline than a substance with a pH of 4.
B. A substance with a pH of 3 is 10 times more alkaline than a substance with a pH of 4.
C. A substance with a pH of 3 is two times more acidic than a substance with a pH of 4.
D. A substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4.
Answer Explanation
The correct answer is d. A substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4. The pH scale is a logarithmic scale, which means that each change of one pH unit represents a tenfold change in the hydrogen-ion concentration. A substance with a pH of 3 has a hydrogen-ion concentration that is 10 times greater than that of a substance with a pH of 4.
A. A substance with a pH of 3 is not two times more alkaline than a substance with a pH of 4.
B. A substance with a pH of 3 is not 10 times more alkaline than a substance with a pH of 4.
C. A substance with a pH of 3 is not two times more acidic than a substance with a pH of 4.
