BIO 112 exam 1

Plants and fungi first became established on land during the A) Archaean. B) Proterozoic. C) Paleozoic. D) Cenozoic.

C) Paleozoic.

which of the following is a defining characteristic that all protocells had in common? 1-a surrounding membrane like structure 2-RNA genes 3- ability to synthesize enzymes 4- the ability to replicate RNA

1- A surrounding membrane like structure

Reinforcement is most likely to occur when ______. 1- hybrids have lower fitness than either parent population 2- The environment is changing 3- prezygotic isolation mechanisms are in place 4- gene flow Is low

1- hybrids have lower fitness than either parent population

Who developed a theory of evolution almost identical to Darwin's? 1-Wallace 2-Lamarck 3-Aristotle 4-Lyell

1-Wallace

Which of the following was derived from an ancestral cyanobacterium? 1-mitochondria 2- chloroplast 3- flagella 4- mitosome

2- chloroplast

Which specie concept distinguishes species based on the genetic exchange between gene pools? 1-phylogenetic 2-biological 3-ecological 4-morphological

2-biological

Macroevolution is___. 1-unlike microevolution, including a macroscopic species 2-evolution above the species level 3-defined as the change in allele frequency of a population 4-defined as a change in the gene frequency over time

2-evolution above the species level

which of the following organisms would be most likely to fossilize? 1-a rare worm 2- a common worm 3- a common squirrel 4- a rare squirrel

3- a common squirrel

Species on islands are different but related to, those on land. This is evidence that___. 1-common environments are inhabited by the same organisms 2-the islands forms and mainland forms are converging 3-the island forms and descended from mainland forms 4-island forms and mainland forms have identical gene pools

3-Island forms and descended from mainland forms

Which most strongly supports the common origin of life on earth? All organisms____. 1-reproduce 2-require energy 3-have a common genetic code 4-show heritable variation

3-have a common genetic code

Unlike Earth today, early Earth _____. 1- Had an oxidizing atmosphere 2- experienced little high energy radiation from the sun 3- had an atmosphere with significant quantities of ozone 4- had an atmosphere rich in gases released from volcanos

4- Had an atmosphere rich in gases released from volcanos

which of the following describes the most likely order of events in allopatric speciation? 1-Genetic drift, genetic isolation, divergence 2-divergence, genetic drift, genetic isolation 3- genetic isolation, divergence, genetic drift 4- genetic isolation, genetic drift, divergence

4- genetic isolation, genetic drift, divergence

Which of the following would prevent an organism from becoming part of the fossil record when it dies? A) It is fully decomposed by bacteria and fungi. B) It is buried in fine sediments at the bottom of a lake. C) It gets trapped in sap. D) It is frozen in ice.

A) It is fully decomposed by bacteria and fungi.

Miller was the first to show that A) amino acids and other organic molecules could have formed under conditions thought to resemble those of early Earth. B) the earliest forms of life were photosynthetic. C) eukaryotic life evolved from early prokaryotes. D) the earliest forms of life had an RNA genome.

A) amino acids and other organic molecules could have formed under conditions thought to resemble those of early Earth.

How were conditions on the early Earth of more than three billion years ago different from those on today's Earth? Unlike Earth today, early Earth _____. A) had an atmosphere rich in gases released from volcanic eruptions B) had an oxidizing atmosphere C) experienced little high energy radiation from the sun D) had an atmosphere with significant quantities of ozone

A) had an atmosphere rich in gases released from volcanic eruptions

Sympatric speciation commonly occurs through ________ in plants but is more likely to occur through ________ in animals. A) polyploidy; habitat differentiation and sexual selection B) habitat differentiation and sexual selection; polyploidy C) asexual reproduction; chromosome duplications D) self-pollination; polyploidy and other genetic mechanisms

A) polyploidy; habitat differentiation and sexual selection

Which of the following types of reproductive barriers separates a pair of species that could interbreed but for the fact that one mates at dusk and the other at dawn? A) temporal isolation B) habitat isolation C) behavioral isolation D) mechanical isolation

A) temporal isolation

One of the finest available sequences of fossils shows how horses have changed slowly and by subtle steps from small shrub-browsing ancestors to the large, grass-grazing modern horse. A large number of fossil species have been named, and it is often difficult to decide on the identity of a fossil horse because transitional forms are common. This record of evolution best fits the idea of A) the gradual model of speciation. B) punctuated equilibrium. C) adaptive radiation. D) hybrid breakdown.

A) the gradual model of speciation.

Rank the following in order from most general to most specific: 1. gametic isolation2. reproductive isolating mechanism3. sperm-egg incompatibility in sea urchins 4. prezygotic isolating mechanism A) 2, 3, 1, 4 B) 2, 4, 1, 3 C) 4, 1, 2, 3 D) 4, 2, 1, 3

B) 2, 4, 1, 3

A population of 1,000 birds exists on a small Pacific island. Some of the birds are yellow, a characteristic determined by a recessive allele. The others are green, a characteristic determined by a dominant allele. A hurricane on the island kills most of the birds from this population. Only 10 remain, and those birds all have yellow feathers. Which of the following statements is true? A) Assuming that no new birds come to the island and no mutations occur, future generations of this population will contain both green and yellow birds. B) The hurricane has caused a population bottleneck and a loss of genetic diversity. C) This situation illustrates the effect of a mutation event. D) The 10 remaining birds will mate only with each other, and this will contribute to gene flow in the population.

B) The hurricane has caused a population bottleneck and a loss of genetic diversity

A dog breeder wishes to develop a breed that does not bark. She starts with a diverse mixture of dogs. Generation after generation, allows only the quietest dogs to breed. After 30 years of work she has a new breed of dog with interesting traits, but on average, the dogs still bark at about the same rate as other dog breeds. Which of the following would be a logical explanation for her failure? A) There is no variation for the trait (barking). B) The tendency to bark is not a heritable trait. C) The selection was artificial, not natural, so it did not produce evolutionary change. D) There was no selection (differential reproductive success) related to barking behavior.

B) The tendency to bark is not a heritable trait.

The largest unit within which gene flow can readily occur is _____. A) a population B) a species C) the entire range of a genus D) the hybrid zone

B) a species

You find the frozen remains of a woolly mammoth in an Alaskan glacier. You analyze a bit of the tusk and find that its 14C:12C ratio is about one-fourth (25%) of the baseline level typically found in living organisms. Given that the half-life of 14C is 5,730 years, when did the mammoth die? A) 5,730 years ago B) almost 12,000 years ago C) at least 25,000 years ago D) approximately 75,000 years ago

B) almost 12,000 years ago

Imagine that you are studying a very large population of moths that is isolated from gene flow. A single gene controls wing color. Half of the moths have white-spotted wings (genotype WW or Ww) and half of the moths have plain brown wings (ww). There are no new mutations, individuals mate randomly, and there is no natural selection on wing color. How will p, the frequency of the dominant allele, change over time? A) p will increase; the dominant allele will eventually take over and become most common in the population. B) p will neither increase nor decrease; it will remain more or less constant under the conditions described. C) p will decrease because of genetic drift. D) p will fluctuate rapidly and randomly because of genetic drift.

B) p will neither increase nor decrease; it will remain more or less constant under the conditions described.

A current leading hypothesis about the first system of inheritance in the earliest life-forms involves A) self-replicating DNA molecules (the "DNA world" hypothesis). B) self-replicating RNA molecules aided by ribozymes. C) proteins that served as templates for RNA molecules, leading to the formation of DNA. D) self-replicating polypeptides aided by ribosomes.

B) self-replicating RNA molecules aided by ribozymes.

Which of these observations gives the most support to the endosymbiotic theory for the origin of eukaryotic cells? A) the existence of structural and molecular differences between the plasma membranes of prokaryotes and the internal membranes of mitochondria and chloroplasts B) the similarity in size between the cytosolic ribosomes of prokaryotes and the ribosomes within mitochondria and chloroplasts C) the size disparity between most prokaryotic cells and most eukaryotic cells D) the observation that some eukaryotic cells lack mitochondria

B) the similarity in size between the cytosolic ribosomes of prokaryotes and the ribosomes within mitochondria and chloroplasts

Which of the following disciplines has found evidence for evolution based on the native distributions (locations) of living species? A) molecular biology B) comparative anatomy C) biogeography D) paleontology

C) Biogeography

Lyell's book Principles of Geology, which Darwin read on board the H.M.S. Beagle, argued in favor of which of the following concepts? A) Earth's surface is shaped mainly by occasional catastrophic events. B) Meteori te impacts may have been a major cause of periodic mass extinctions. C) Earth's surface is shaped by natural forces that act gradually and are still acting. D) The processes that shape Earth today are very different from those that were at work in the past

C) Earth's surface is shaped by natural forces that act gradually and are still acting.

Which of the following statements regarding the definition of species is false? A) The ecological species concept identifies species in terms of their ecological niches. B) The phylogenetic species concept defines a species as a set of organisms that shares a common ancestor and forms one branch on the tree of life. C) The morphological species concept relies upon comparing the DNA sequences of organisms. D) Under the biological species concept, the gap between species is maintained by reproductive isolation.

C) The morphological species concept relies upon comparing the DNA sequences of organisms.

House finches were found only in western North America until 1939, when a few individuals were released in New York City. These individuals established a breeding population and gradually expanded their range. The western population also expanded its range somewhat eastward, and the two populations have recently come in contact. If the two forms were unable to interbreed when their expanding ranges met, it would be an example of _____. A) prezygotic isolation B) reinforcement C) allopatric speciation D) sympatric speciation

C) allopatric speciation

which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools? A) phylogenetic B) ecological C) biological D) morphological

C) biological

Two species that occasionally mate and produce zygotes, but that have incompatible genes that prevent the resulting embryo from developing, are affected by A) gametic isolation. B) reduced hybrid fertility. C) reduced hybrid viability. D) hybrid breakdown.

C) reduced hybrid viability.

Aristotle believed that A) species evolve through natural selection and other mechanisms. B) an individual's use of a body part causes it to further evolve. C) species are fixed (permanent) and perfect. D) the best evidence for change within species is seen in fossils

C) species are fixed (permanent) and perfect.

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) a change in the gene pool of a population from one generation to the next

D) a change in the gene pool of a population from one generation to the next

Which of the following organisms would be most likely to fossilize? A) a rare worm B) a common worm C) a rare squirrel D) a common squirrel

D) a common squirrel

Microevolution, or evolution at its smallest scale, occurs when A) an individual's traits change in response to environmental factors. B) a community of organisms changes due to the extinction of several dominant species. C) a new species arises from an existing species. D) a population's allele frequencies change over a span of generations.

D) a population's allele frequencies change over a span of generations.

If a fossil is encased in a stratum of sedimentary rock without any strata of volcanic rock (for example, lava or ash) nearby, then it should be _____. A) easy to determine the absolute age of the fossil, because the radioisotopes in the sediments will not have been "reset" by the heat of the igneous rocks B) easy to determine the absolute age of the fossil, because the igneous rocks will not have physically obstructed the deposition of sediment of a single age next to the fossil C) difficult to determine the absolute age of the fossil, because the "marker fossils" common to igneous rock will be absent D) difficult to determine the absolute age of the fossil, because radiometric dating of sedimentary rock is less accurate than that of igneous rock

D) difficult to determine the absolute age of the fossil, because radiometric dating of sedimentary rock is less accurate than that of igneous rock

Which of the following steps has yet to be accomplished by scientists studying the origin of life? A) synthesis of small RNA polymers by ribozymes B) abiotic synthesis of polypeptides C) formation of molecular aggregates with selectively permeable membranes D) formation of protocells that use DNA to direct the polymerization of amino acids

D) formation of protocells that use DNA to direct the polymerization of amino acids