Ques:Answer the following question given this paragraph: The lungs of mammals are unique in having alveoli. These are tiny, sac-like structures. Each alveolus is surrounded by a network of very small blood vessels (see Figure below ). Because there are millions of alveoli in each lung, they greatly increase the surface area for gas exchange between the lungs and bloodstream. Human lungs, for example, contain about 300 million alveoli. They give the lungs a total surface area for gas exchange of up to 90 square meters (968 square feet). That's about as much surface area as one side of a volleyball court!. Q: What in mammalian lungs, increases the surface area for gas exchange? Choices: - bronchi - thorax - bronchioles - alveoli A:

Ans:alveoli
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Ques:Answer the following question given this paragraph: Q: What is the respiratory pigment of almost every vertebrate? Choices: - insulin - plasma - iron - hemoglobin A:

Ans:hemoglobin
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Ques:Answer the following question given this paragraph: Cytokinins promote cell division and are necessary for growing plants in tissue culture. A small piece of a plant is placed in sterile conditions to regenerate a new plant. Q: What promotes cell division and are necessary for growing plants in tissue culture? Choices: - polyamines - auxins - mitochondria - cytokinins A:

Ans:cytokinins
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Ques:Answer the following question given this paragraph: An atom has negatively-charged electrons in orbit around its nucleus. Q: What orbits an atoms' nucleus? Choices: - neutrally charged ions - positively charged protons - isotopes - negatively charged electrons A:

Ans:
negatively charged electrons
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