1. Mendel conducted his most memorable experiments on A) peas. B) roses. C) guinea pigs. D) fruit flies. E) clones. 2. Varieties of plants in which self-fertilization produces offspring that are identical to the parents are referred to as A) hybrids. B) the F2 generation. C) monohybrid crosses. D) independent crosses. E) true-breeding. 3. Which of the following statements regarding cross-breeding and hybridization is false? A) The offspring of two different varieties are called hybrids. B) Hybridization is also called a cross. C) The parental plants of a cross are the P generation. D) The hybrid offspring of a cross are the P1 generation. E) The hybrid offspring of an F1 cross are the F2 generation. 4. Which of the following statements regarding genotypes and phenotypes is false? A) The genetic makeup of an organism constitutes its genotype. B) An organism with two different alleles for a single trait is said to be heterozygous for that trait. C) Alleles are alternate forms of a gene. D) An allele that is fully expressed is referred to as recessive. E) The expressed physical traits of an organism are called its phenotype. 5. The alleles of a gene are found at chromosomes. A) the same locus on homologous mitochondrial B) the same locus on heterologous C) different loci on homologous D) different loci on heterologous E) the same locus on homologous 6. The phenotypic ratio resulting from a dihybrid cross showing independent assortment is expected to be A) 1:2:1. B) 3:1. C) 9:1:1:3. D) 3:9:9:1. E) 9:3:3:1. Page 1 of 7 BIO 110 SM 2015 67163 Q 4 Genetics and Evolution 150709.3
7. Most genetic disorders of humans are caused by A) multiple alleles. B) recessive alleles. C) drinking during pregnancy. D) a mutation that occurs in the egg, sperm, or zygote. E) dominant alleles. 8. The vast majority of people afflicted with recessive disorders are born to parents who were A) both affected by the disease. B) not affected at all by the disease. C) slightly affected by the disease, showing some but not all of the symptoms. D) subjected to some environmental toxin that caused the disease in their children. E) affected by the disease but had subclinical symptoms. 9. All the offspring of a cross between a red-flowered plant and a white-flowered plant have pink flowers. This means that the allele for red flowers is to the allele for white flowers. A) dominant B) codominant C) pleiotropic D) incompletely dominant E) recessive 10. The individual features of all organisms are the result of A) genetics. B) the environment. C) genetics and cytoplasmic determinants. D) the environment and individual needs. E) genetics and the environment. 11. The chromosome theory of inheritance states that A) chromosomes that exhibit mutations are the source of genetic variation. B) the behavior of chromosomes during meiosis and fertilization accounts for patterns of inheritance. C) the behavior of chromosomes during mitosis accounts for inheritance patterns. D) humans have 46 chromosomes. E) the inheritance pattern of humans is predetermined from chromosomes. 12. Crossing over genes into assortments of not found in the parents. A) recombines unlinked... genes B) recombines linked... alleles C) combines unlinked... alleles D) combines linked... genes E) recombines unlinked... chromosomes Page 2 of 7 BIO 110 SM 2015 67163 Q 4 Genetics and Evolution 150709.3
13. The sex chromosome complement of a normal human male is A) XO. B) XX. C) XY. D) YY. E) YO. 14. How many sex chromosomes are in a human gamete? A) one B) two C) three D) four E) five 15. The core theme of biology is A) taxonomy. B) genetics. C) ecology. D) evolution. E) metabolism. 16. Darwin found that some of the species on the Galápagos islands resembled species of the South American mainland A) less than they resembled animals on ecologically similar but distant islands. B) more than they resembled animals on ecologically similar but distant islands. C) less than they resembled animals in Europe. D) less than they resembled animals from Australia. E) very closely; in most cases, the species from the mainland and the islands were identical. 17. Broccoli, cabbages, and brussels sprouts all descend from the same wild mustard and can still interbreed. These varieties were produced by A) speciation. B) artificial selection. C) natural selection. D) genetic drift. E) inheritance of acquired characteristics. 18. Which of the following best expresses the concept of natural selection? A) differential reproductive success based on inherited characteristics B) inheritance of acquired characteristics C) change in response to need D) a process of constant improvement, leading eventually to perfection E) survival of the fittest Page 3 of 7 BIO 110 SM 2015 67163 Q 4 Genetics and Evolution 150709.3
19. Humans share several features with salamanders. Certain genes and proteins are nearly identical between the two species; both species have four limbs with a similar skeletal structure; the species' early embryos are very similar; and where the salamander has a functional tail, humans have a vestigial tailbone. In evolutionary terms, these are examples of A) biogeographic similarity. B) homology. C) independently acquired characteristics. D) adaptation by natural selection. E) coincidental similarity. 20. Which of the following represents a pair of homologous structures? A) the wing of a bat and the scales of a fish B) the wing of a bat and the flipper of a whale C) the antennae of an insect and the eyes of a bird D) the feathers of a bird and the wing membrane of a bat E) the wing of a bat and the wing of a butterfly 21. Darwin was the first person to draw an evolutionary tree, a diagram that represents A) records of breeding in domesticated animals. B) records of lineages in humans (also known as a family tree). C) final, factually established evolutionary relationships among different groups of organisms. D) evidence-based hypotheses regarding our understanding of patterns of evolutionary descent. E) groupings of organisms based on overall similarity. 22. A population is A) a group of individuals of the same species living in the same place at the same time. B) all individuals of a species, regardless of location or time period in which they live. C) a group of individuals of different species living in the same place at the same time. D) a group of individuals of a species plus all of the other species with which they interact. E) a group of species that share a common characteristic. 23. Microevolution, or evolution at its smallest scale, occurs when A) an individual's traits change in response to environmental factors. B) a geographic area is altered by erosion, volcanic eruptions, or other geological forces. C) a community of organisms changes due to the extinction of several dominant species. D) a new species arises from an existing species. E) a population's allele frequencies change over a span of generations. 24. The ultimate source of all new alleles is A) mutation in parent cells (asexual organisms) or in cells that produce gametes (sexual organisms). B) any form of mutation, regardless of the cell type. C) chromosomal duplication. D) genetic drift. E) natural selection. Page 4 of 7 BIO 110 SM 2015 67163 Q 4 Genetics and Evolution 150709.3
25. Genetic drift resulting from a disaster that drastically reduces population size is called A) natural selection. B) gene flow. C) the bottleneck effect. D) nonrandom mating. E) the founder effect. 26. Thirty people are selected for a long-term mission to colonize a planet many light years away from Earth. The mission is successful and the population rapidly grows to several hundred individuals. However, certain genetic diseases are unusually common in this group, and their gene pool is quite different from that of the Earth population they have left behind. Which of the following phenomena has left its mark on this population? A) founder effect B) bottleneck effect C) gene flow D) high rates of mutation E) natural selection 27. Genetic differences between populations tend to be reduced by A) gene flow. B) mutation. C) the founder effect. D) the bottleneck effect. E) natural selection. 28. Which sentence best describes the true nature of natural selection? A) Survival of the fittest. B) Only the strongest survive. C) The strong eliminate the weak in the race for survival. D) Organisms change by random chance. E) Heritable traits that promote reproduction become more frequent in a population from one generation to the next. 29. Which of the following will tend to produce adaptive changes in populations? A) genetic drift B) gene flow C) mutation D) natural selection E) the founder effect Page 5 of 7 BIO 110 SM 2015 67163 Q 4 Genetics and Evolution 150709.3
30. An elk herd is observed over many generations. Most of the full-grown bull elk have antlers of nearly the same size, although a few have antlers that are significantly larger or smaller than this average size. The average antler size remains constant over the generations. Which of the following effects probably accounts for this situation? A) directional selection B) stabilizing selection C) a bottleneck effect that resulted in low genetic diversity D) a founder effect E) a high rate of gene flow 31. Speciation, or the formation of new species, is A) a form of microevolution. B) completed when the new species is able to interbreed with at least one additional species. C) the bridge between microevolution and macroevolution. D) a process that requires at least 1 million years, as seen in the Lake Victoria cichlids. E) an event that has occurred only a few times in the history of the planet. 32. Which of the following would a biologist describe as microevolution? A) the formation of new species B) the extinction of species C) dramatic biological changes, such as the origin of flight, within a taxon D) the generation of biodiversity E) a change in allele frequencies within the gene pool of a population 33. A biological species is defined as a group of organisms that A) are physically similar. B) are genetically similar. C) share a recent common ancestor. D) live together in a location and carry out identical ecological roles. E) have the potential to interbreed in nature and produce fertile offspring. 34. The biological species concept is A) applicable to all forms of life, past and present. B) applicable to all present life forms, but not to fossil organisms whose reproductive behavior cannot be observed. C) easy to apply to all present sexually reproducing organisms, but harder to apply to asexual organisms and fossils. D) difficult to put into practice even for present sexual organisms, and useless for asexual organisms and fossils. E) based on DNA, so it applies to all forms of life from which a DNA sample can be collected. Page 6 of 7 BIO 110 SM 2015 67163 Q 4 Genetics and Evolution 150709.3
35. In most but not all cases, Two populations of organisms belong to the same biological species when they A) can't mate with each other, because mating occurs at different times. B) mate with each other, but produce offspring that are not vigorous (suffer reduced viability). C) use different types of behaviors or physical features to attract mates. D) have anatomical features that make it difficult for organisms from the different populations to mate. E) encounter each other, mate, and produce viable, fertile offspring under natural conditions. 36. Which of the following types of reproductive barriers separates a pair of species that could interbreed except that one mates at dusk and the other at dawn? A) temporal isolation B) habitat isolation C) behavioral isolation D) mechanical isolation E) gametic isolation 37. The emergence of a new plant species over a brief period of time, followed by a long period of little change, is consistent with which of the following theories? A) the gradualism model B) allopatric speciation C) punctuated equilibrium D) phylogenetic divergence E) adaptive radiation 38. When the Earth first solidified, what were conditions like? A) The atmosphere was similar to today's atmosphere, but there was more volcanic activity. B) The atmosphere was rich in gases released in volcanic eruptions, but otherwise physical conditions were similar to those seen on Earth today. C) The atmosphere was rich in gases released in volcanic eruptions, and volcanic activity was intense, but very little ultraviolet light reached Earth's surface because of the thick atmosphere. D) The atmosphere was rich in gases released in volcanic eruptions; volcanic activity, lightning, and ultraviolet radiation were all much more intense than on today's Earth. E) It was just like Earth today, except there was no life. 39. The earliest discovered fossils are of dating back to years ago. A) single-celled eukaryotes... 4.5 billion B) prokaryotes... 3.5 billion C) algae... 1 billion D) fish... 600 million E) dinosaurs... 180 million Page 7 of 7 BIO 110 SM 2015 67163 Q 4 Genetics and Evolution 150709.3