Biology

If natural selection in a particular environment favored genetic systems that pe

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An organism has a relatively large number of Hox genes in its genome. Which of t

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Bagworm moth caterpillars feed on evergreens and carry a silken case or bag arou

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A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolut

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A genetic change that caused a certain Hox gene to be expressed along the tip of

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Which of the following steps has not yet been accomplished by scientists studyin

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Adaptive radiations can be a direct consequence of four of the following five fa

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Which factor most likely caused animals and plants in India to differ greatly fr

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The oxygen revolution changed Earth's environment dramatically. Which of the fol

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Fossilized stromatolites A) all date from 2.7 billion years ago. B) formed aroun

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Fossil evidence indicates that several kinds of flightless dinosaurs possessed f

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Larval flies (maggots) express the Ubx gene in all of their segments, and thereb

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The loss of ventral spines by modern freshwater sticklebacks is due to natural s

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Several scientific laboratories across the globe are involved in research concer

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Recent evidence indicates that the first major diversification of multicellular

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If it were possible to conduct sophisticated microscopic and chemical analyses o

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What is thought to be the correct sequence of these events, from earliest to mos

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What is true of the Cambrian explosion? A) There are no fossils in geological st

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The synthesis of new DNA requires the prior existence of oligonucleotides to ser

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The first genes on Earth were probably A) DNA produced by reverse transcriptase

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Which of the following is a defining characteristic that all protobionts had in

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Which of the following is the correct sequence of events in the origin of life?

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What is true of the amino acids that might have been delivered to Earth within c

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How were conditions on the early Earth of more than 3 billion years ago differen

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Which of these observations gives the most support to the endosymbiotic theory f

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