Term Test 1 2006 - Term Test 1 page 1 of 8 1. A key point...

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Term Test 1 page 1 of 8 1. A key point in Darwin’s explanation of evolution is that the biological structures most likely inherited are those that have become better suited to the environment because a. extinction is nature’s way of weeding out undeserving organisms. b. genes change in order to help organisms cope with problems encountered within their environments. c. mutations that occur are those that will help future generations fit into their environments. d. slight variations among individuals significantly affect the chance that a given individual will survive in its environment and be able to reproduce. 2. Over time, mutations are important to evolution because a. Mutations are usually beneficial to offspring. b. Whether good or bad, mutations increase the fitness of an individual. c. Most mutation rates are about 1 in 10 6 - 10 9 cell divisions. d. Mutations are the original source of variation. e. Once an allele is changed through mutation, another mutation to that same allele cannot happen. 3. Selection acts on ________ variation; however, evolution depends on ______ variation in the population. a. phenotypic; genetic b. genetic; phenotypic c. genetic; environmentally-induced d. environmentally-induced; phenotypic e. environmentally-induced; genetic 4. Consider the example of sickle-cell anemia discussed in lecture and your text. Which of the following can be concluded from this example? a. Changes in the nucleotide sequences of a gene must involve several nucleotides for there to be an effect on the phenotype of the individual. b. Changes to the genotype of even one nucleotide can affect the phenotype. c. Only one form of a particular gene can be found within diploid individuals. d. Most mutations have no effect on the organism. 5. Evolution by natural selection is a powerful force of change. What keeps organisms from becoming perfectly adapted to their environment? a. Environments change, so different alleles become more fit. b. Genetic drift causes random changes in allele frequencies. c. Mutations introduce new variation into a population. d. All of the above processes impede, constrain, or accelerate evolution by natural selection. e. Many organisms have become perfectly adapted to their environment. 6. Which of the following processes is not the result of chance, random events? a. mutation b. natural selection c. genetic drift by a bottleneck d. genetic drift by a founder effect BIO152H5F Term Test 1 2006
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Term Test 1 page 2 of 8 Read this passage for the following 3 questions BIOLOGICAL EVOLUTION What exactly do biologists mean when they say that they have observed evolution or that humans and chimps have evolved from a common ancestor? One of the most respected evolutionary biologists has defined biological evolution as follows: “In the broadest sense, evolution is merely change, and so is all-pervasive; galaxies, languages, and political systems all evolve. Biological evolution is change in the properties of organisms that transcend the lifetime of a single individual. The developmental changes of an
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This note was uploaded on 12/03/2009 for the course BIO BIO152 taught by Professor Cordon during the Spring '09 term at University of Toronto- Toronto.

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Term Test 1 2006 - Term Test 1 page 1 of 8 1. A key point...

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