Ques:Answer the following question given this paragraph: Flame Cells of Planaria and Nephridia of Worms As multi-cellular systems evolved to have organ systems that divided the metabolic needs of the body, individual organs evolved to perform the excretory function. Planaria are flatworms that live in fresh water. Their excretory system consists of two tubules connected to a highly branched duct system. The cells in the tubules are called flame cells (or protonephridia) because they have a cluster of cilia that looks like a flickering flame when viewed under the microscope, as illustrated in Figure 41.10a. The cilia propel waste matter down the tubules and out of the body through excretory pores that open on the body surface; cilia also draw water from the interstitial fluid, allowing for filtration. Any valuable metabolites are recovered by reabsorption. Flame cells are found in flatworms, including parasitic tapeworms and free-living planaria. They also maintain the organism's osmotic balance. Q: How are valuable metabolites recovered? Choices: - replication reaction - osmosis - metabolism - reabsorption A:

Ans:reabsorption
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Ques:Answer the following question given this paragraph: Aldehydes and ketones can work weak hydrogen bonds with water through the carbonyl oxygen atom. The lower members of both series (3 carbons or fewer) are soluble in water in all proportions. As the length of the carbon chain increases, water solubility decreases. Similar to ethers, neither aldehydes nor ketones can hydrogen bond with themselves. As a result, their boiling points are generally lower than those of alcohols. Unlike alkanes however, aldehydes and ketones are polar molecules due to the more electronegative oxygen atom. The dipole-dipole interactions are stronger than the dispersion forces present in alkanes. The boiling points of aldehydes and ketones are intermediate between those of alkanes and alcohols. For example, the boiling point of ethane is -89C, ethanal is 20C, and ethanol is 78C. Q: Aldehydes and ketones can work weak hydrogen bonds with water through what atom? Choices: - basalt oxygen atom - pyridinium oxygen atom - carbon carbon atom - carbonyl oxygen atom A:

Ans:carbonyl oxygen atom
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Ques:Answer the following question given this paragraph: Hydrocarbons are compounds that contain only carbon and hydrogen atoms. The smallest hydrocarbon, methane (CH 4 ), contains just one carbon atom and four hydrogen atoms. Larger hydrocarbons contain many more. Hydrocarbons with four or more carbon atoms can have different shapes. Although they have the same chemical formula, with the same numbers of carbon and hydrogen atoms, they form different compounds, called isomers . Isomers are compounds whose properties are different because their atoms are bonded together in different arrangements. Q: What do you call compounds whose properties are different because their atoms are bonded together in different arrangements? Choices: - isotopes - mixtures - ionic compounds - isomers A:

Ans:isomers
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Ques:Answer the following question given this paragraph: A heat wave over the United States as indicated by heat radiated from the ground. The bright yellow areas are the hottest, and the blue and white are coolest. Q: In a heat map, what color represents the hottest temperatures? Choices: - bright red - orange - pink - bright yellow A:

Ans:
bright yellow
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