About how much of the atmosphere is composed of nitrogen?

A) 23 percent B) 1 percent C) 78 percent D) 52 percent


Answer: C

Biology & Microbiology

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In which choice are the entries listed from smallest to largest?

A) DNA building block - gene - chromosome - genome B) DNA building block - RNA building block - protein C) Gene - cell - DNA - genome D) Chromosome - genome - cell - DNA building block

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Which endocrine gland is the main center for control of the internal environment?

a. pineal b. hypothalamus c. thyroid d. adrenal cortex e. thalamus

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__________ are teeth adapted primarily for tearing food

a. Bicuspids b. Canines c. Incisors d. Molars e. Premolars

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The bicuspid (mitral) valve

A. is the location of the pacemaker cells of a normal heart. B. prevents blood flow from the right ventricle to the right atrium. C. prevents blood flow from the left ventricle to the left atrium. D. prevents blood flow from the pulmonary artery to the right ventricle. E. prevents blood flow from the aorta to the left ventricle.

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