Which of the following terms describes the relaxation of the chambers of the heart during the cardiac cycle?
A. Tachycardia
B. Diastole
C. Systole
D. Bradycardia
The relaxation of the chambers of the heart during the cardiac cycle is called diastole ¹. The cardiac cycle is a sequence of events that occurs when the heart beats ². It consists of two phases: systole, when the heart contracts and pumps blood into circulation, and diastole, when the heart relaxes and fills with blood ².
The other options are not correct because they do not accurately describe the relaxation of the chambers of the heart during the cardiac cycle. Tachycardia is a rapid heart rate, bradycardia is a slow heart rate, and systole is the contraction of the heart chambers.
Therefore, the Correct Answer is B.
More Questions on TEAS 7 Science
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Q #1: 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.
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Q #2: Which of the following layers of skin lack blood vessels?
A. Papillary
B. Epidermis
C. Reticular
D. Hypodermis
Answer Explanation
The layer of skin that lacks blood vessels is the epidermis. The epidermis is the thin outer layer of the skin and does not have any blood vessels within it. It is composed of keratinized, stratified squamous epithelium and is made of four or five layers of epithelial cells, depending on its location in the body.
The other options are not correct because they do contain blood vessels. The papillary layer is part of the dermis, which contains blood vessels. The reticular layer is also part of the dermis and contains blood vessels . The hypodermis is a layer below the dermis and also contains blood vessels.
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Q #3: The mitochondrial inner membrane carries out the same function in cellular respiration as the ________ membrane of chloroplasts in photosynthesis. Which of the following correctly completes the sentence above?
A. Thylakoid
B. Epithelial
C. Nuclear
D. Tonoplast
Answer Explanation
The thylakoid membrane of chloroplasts is where the light-dependent reactions of photosynthesis take place, while the mitochondrial inner membrane is where the electron transport chain and ATP synthesis occur during cellular respiration.
The tonoplast is the membrane that surrounds the central vacuole in plant cells. It is not involved in cellular respiration or photosynthesis.
The other options, epithelial and nuclear, are not related to these processes.
