Biology Exam #1

Phylogeny

The evolutionary history of a species or a group of species is referred is termed a _____.

c. Triazine-resistant weeds were more likely to survive and reproduce

A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these statements explains why the pigweed reappeared? a. Natural selection caused the pigweed to mutate, creating a new triazine-resistant species b. The herbicide company lost its triazine formula and started selling poor-quality triazine. c. Triazine-resistant weeds were more likely to survive and reproduce d. Triazine-resistant pigweed has less-efficient photosynthesis metabolism.

b. increased variation in beak size and shape over time

After the drought of 1977, researchers hypothesized that on the Galápagos Island Daphne Major, medium ground finches with large, deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus cistoides fruits. A tourist company sets up reliable feeding stations with a variety of bird seeds (different types and sizes) so that tourists can get a better look at the finches. Which of these events is now most likely to occur to finch beaks on this island? a. evolution of smaller, pointier beaks over time, until all birds have relatively small, pointy beaks b. increased variation in beak size and shape over time c. no change in beak size and shape over time d. evolution of yet larger, deeper beaks over time, until all birds have relatively large, deep beaks

Hybrids

Barriers that block gene flow between the species limit the formation of ____, offspring that result from an interspecific mating.

b. Wallace

During his first voyage, ___________________ lost nearly all of his collected specimens and suffered severe rope burns to his hands as he escaped his burning ship that eventually sunk. a. Hutton b. Wallace c. Darwin d. Lyell e. Lamarck

Microevolution is the process by which a population may change, but does not lead to changes in allele frequency that cause speciation. Antibiotic resistance is an example of microevolution in that the selection for a mutation that allows for antibiotic resistance upon the introduction of antibiotics to a virus or bacteria results in a process of selection for the mutation that allows this resistance, as the nonresistant types will die out in a body with antibiotics, and the resistant will survive. This process will not lead to speciation, however, as it is the response to the immediate introduction of antibiotics, and both resistant and nonresistant types will continue to survive and remain one in the end, unaffected by the periodic, quicker fluctuations of the microevolution process. The allele frequencies will not change over the generations, and will not lead to speciation.

Explain how the development of antibiotic resistance is an example of microevolution.

d. Gradual evolutionary change explains why organisms are well-suited to their environments

For which one of the following observations were both Lamarck's hypothesis and Darwin's hypothesis in complete agreement? a. Acquired characteristics are inherited b. Use and disuse of organs determines their size in progeny c. More complex species are descended from less complex species d. Gradual evolutionary change explains why organisms are well-suited to their environments

b. older strata carry fossils that differ greatly from living organisms

Fossils found in strata reveal that ________. a. geologic changes occur quickly on Earth b. older strata carry fossils that differ greatly from living organisms c. innate drive to complexity of life d. unused body parts decrease in size

2 → 4 → 1 → 3

Given a population that contains genetic variation, what is the correct sequence of the following events under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly-adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly-adapted individuals have decreased survivorship.

b. microevolution

Increase in average beak depth of soap berry bugs following the introduction of the goldenrain tree in central Florida is a good example of: a. macroevolution b. microevolution c. inheritance of acquired characteristics d. hybridization e. speciation

Adaptations

Inherited characteristics of organisms that enhance their survival and reproduction in specific environments are termed ______.

c. Relationships between DNA sequences among the species did not match relationships between skeletal patterns

Logically, which of these should cast the most doubt on the relationships depicted by an evolutionary tree? a. The skeletal remains of the organisms depicted by the tree were incomplete (in other words, some bones were missing). b. Transitional fossils had not been found c. Relationships between DNA sequences among the species did not match relationships between skeletal patterns d. None of the organisms depicted by the tree ate the same foods. e. Some of the organisms depicted by the tree had lived in different habitats

a. the same as microevolution, but includes the origin of new species, c. evolution above the species level

Macroevolution is ________. a. the same as microevolution, but includes the origin of new species b. defined as the evolution of microscopic organisms into organisms that can be seen with the naked eye c. evolution above the species level d. defined as a change in allele or gene frequency over the course of many generations

c. Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits.

Over long periods of time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses? a. The ancestors of these organisms experienced harmful mutations that forced them to lose these structures. b. Natural selection accounts for these losses by the principle of use and disuse. c. Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits. d. Natural selection cannot account for losses, but accounts only for new structures and functions.

Allopatric speciation, the process by which a species diverges and its separate populations become unable to interbreed and become two separate species as defined by the biological species concept through geographic isolation. One hypothetical scenario that could exemplify this process could be the destruction of a land bridge that connected two masses of land surrounded by water. A land-bound species that once populated both land masses become separated geographically, and are unable to meet or breed. Over time, through mutation or genetic drift or other means, each population may become increasingly different from the other, especially if one land mass is significantly different in habitat to the other. If these species were to be reintroduced, they may be met with reproductive barriers, and be unable to produce viable, fertile offspring. Through this process, the species would become two separate species through geographic isolation.

Provide a hypothetical scenario in which allopatric speciation could occur.

a. hybrids have lower fitness than either parent population

Reinforcement is most likely to occur when ________. a. hybrids have lower fitness than either parent population b. gene flow is low c. prezygotic isolating mechanisms are in place d. the environment is changing

c. convergent evolution

Some beetles and flies have antler-like structures on their heads, much like male deer do. The existence of antlers in beetle, fly, and deer species with strong male-male competition is an example of ________. a. homology b. a synapomorphy c. convergent evolution d. parsimony

Darwin's four postulates, the premises for his key ideas regarding natural selection, required that (1) there be variability within a population, which allows for differences to be selected for. (2) These variabilities must be heritable, as the traits that vary among a population must be able to be passed down through the genes of the parents in order to have an impact on the population. (3) These traits must determine biological fitness, or the differing abilities of individuals to survive and reproduce. (4) The survival and reproduction must be nonrandom- it must depend on the variation in the population. These four postulates serve as premises for natural selection, as a population must experience some variety, (whether by mutation, or genetic drift, or other means), and the traits that appear in this variation must either help or hinder the individual's survival. Natural selection is then able to act on these individuals, as individuals with traits better fit for their environment will be better able to survive and reproduce, and thus pass on more of their genes (and thus their heritable variation) to their offspring, gradually shifting the allele frequency of the population as a whole through the process of evolution. These four postulates serve as the premises for Darwin's four key ideas regarding natural selection, including the ideas that natural selection acts on individuals, not for the good of the species, but the consequences are seen in the population. Natural selection also acts on phenotype, whereas evolution is the shift in allele frequencies over time.

The following four key words are from Darwin's postulates: variability, heritable, differential survivorship or reproductive rate, nonrandom. Summarize the process of natural selection in terms of Darwin's four postulates.

e. homology

The presence of a pharyngeal pouches during some part of the life cycle of the chordates is considered evidence of: a. homoplasy b. development c. genetic drift d. analogy e. homology

d. reduced hybrid fertility

The production of sterile mules by interbreeding between female horses (mares) and male donkeys (jacks) is an example of ________. a. hybrid breakdown b. mechanical isolation c. reduced hybrid viability d. reduced hybrid fertility

a. a vestigial structure

The structural remnants of a pelvic bone (pelvic spur) in boas and pythons is an example of: a. a vestigial structure b. mutation c. convergent evolution d. structural homology e. sympatric speciation

c. The legless condition found in various lineages of extant lizards

The term "homoplasy" is most applicable to which of the following features? a. The five-digit condition of human hands and bat wings b. The bones of bat forelimbs and the bones of bird forelimbs c. The legless condition found in various lineages of extant lizards d. The fur that covers Australian moles and North American moles e. The β hemoglobin genes of mice and of humans

d. Linnaeus

This individual established a nested hierarchical classification system and the binomial nomenclature still used today for naming species. a. Darwin b. Cuvier c. Lamarck d. Linnaeus e. Wallace

c. A behavioral reproductive isolating mechanism

Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact? a. A postzygotic isolating mechanism b. A temporal reproductive isolating mechanism c. A behavioral reproductive isolating mechanism d. A gametic reproductive isolating mechanism

c. Habitat isolation

Two populations of birds with somewhat different coloration live on opposite sides of a peninsula. The habitat between the populations is not suitable for these birds. When birds from the two populations are brought together, they produce young whose appearance is intermediate between the two parents. These offspring will breed with each other or with birds from either parent population, and all offspring of these pairings appear intermediate to various degrees. What keeps the two populations separate? a. Lack of hybrid viability b. Behavioral reproductive isolation c. Habitat isolation d. Temporal reproductive isolation

a. Genetic isolation, genetic drift, and divergence

Which of the following describes the most likely order of events in allopatric speciation? a. Genetic isolation, genetic drift, and divergence b.Genetic isolation, divergence, and genetic drift c. Divergence, genetic isolation, and genetic drift d. Genetic drift, genetic isolation, and divergence e. Divergence, genetic drift, and genetic isolation

b. Cell walls in plants and fungi

Which of the following is an example of homoplasy? a. Scales in snakes and lizards b. Cell walls in plants and fungi c. Chlorophyll in flowering plants and algae d. Fur in bears and seals

a. I and III

Which of the following statements about species, as defined by the biological species concept, is (are) correct? I. Biological species are defined by reproductive isolation. II. Biological species are the model used for grouping extinct forms of life. III. All members of a species can potentially interbreed. a. I and III b. II and III c. I, II, and III d. I and II

b. hybrid breakdown

Which postzygotic barriers prevent formation of hybrids beyond the first generations? a. hybrid gamete isolation b. hybrid breakdown c. increased hybrid fertility d. increased hybrid vulnerability

c. morphological

You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use? a. genetic b. ecological c. morphological d. biological

b. To serve as an outgroup

Your professor wants you to construct a phylogenetic tree of orchids. She gives you tissue from seven orchid species and one lily. What is the most likely reason he gave you the lily? a. To see if the lily and the orchids show all the same shared derived characters b. To serve as an outgroup c. To demonstrate likely homoplasies d. To see if the lily is a cryptic orchid species

Natural selection

___ is a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than do other individuals because of those traits.

Vestigial

___ structures are remnant of features that served a function in the organism's ancestors.