FINAL EXAM - EVOLUTION

a.Eukaryotes shared a common ancestor with species in the domain Archaea. B.Eukaryotic "informational" genes are most closely related to archaeal genes, while their "operational" genes are most closely related to bacterial genes.

A number of evolutionary studies show a strong phylogenetic link between prokaryotic and eukaryotic cells. Which of the following is the best statement about the evolutionary origins of eukaryotic cells?

A.Eukaryotic cells probably evolved through endosymbiosis, in which either the archaeal or bacterial cell was engulfed within the other. b.The eukaryotic lineage probably began when an archaeal cell became integrated into a bacterial cell. c.Eukaryotic cells probably evolved when a parasitic species of bacteria residing in another prokaryotic cell became less harmful. d.The eukaryotic lineage probably began when a bacterial cell became integrated into an archaeal cell.

An analysis by Maria Rivera and James Lake suggests that ancient eukaryotic cells emerged from the fusion of an archaeal cell (most likely from the phylum Eocyta) and a bacterium (Rivera and Lake 2004). Which of the following is correct regarding this working hypothesis?

a.Cretaceous-Paleogene boundary B.Permian c.Devonian d.Triassic

As opposed to background extinction, a mass extinction typically refers to the loss of many groups of organisms over a broad geographic range. Which of the following mass extinctions in Earth's geological history was the most devastating for the marine families?

a. The Excavate clade is the only eukaryotic group where all clade members are unicellular . b. The Amoebozoa clade is the only eukaryotic group with clades including members that are both unicellular and multicellular. C. Animals are the only group within the Opisthokont clade whose members are all multicellular. d. All plants and algae are multicellular.

Based on the figure shown, which of the following statements is correct?

a.ancient protozoa b.cyanobacteria c.archaea D.proteobacteria

In 1970, Lynn Margulis proposed that the origin of two eukaryotic organelles, mitochondria and chloroplasts, occurred through endosymbiosis. According to more recent phylogenetic analyses based on molecular genetic data, which of these prokaryotic lineages is a candidate for the ancestral source of mitochondria?

a.He found ribose in very low supply. b.He found that a mechanism for joining the amino acids together to make proteins was completely absent. c.He added CO and had success with creating polypeptides. D.He found some peptide-like structures, but the bonds between the amino acids were weak and unstable.

In 1977, Sidney Fox tried a different approach to testing the prebiotic synthesis of biological molecules. He mixed a number of different amino acids together at a high temperature (120°C) in an environment lacking water. When he subsequently placed the mixture into water to investigate what the amino acids would form, what happened next?

a.punctuated equilibrium b.global warming extinctions c.mass extinctions D.background extinctions

In all of the extinctions that have ever occured on Earth, the majority of species loss was due to ________.

A.all of the answer options are correct b.atmospheric scientists c.geologists d.chemists

In order to understand the origin of life on Earth, evolutionary biologists collaborate with _________.

a.MADS-box genes B.Hox genes c.enhancers d.silencers

In the early 1980s, studies of fruit flies led to the discovery of the master-switch genes involved in animal development. Which of these genes are essential for the development of different body segments of fruit flies?

A.cyclic adenosine monophosphate (cAMP) b.lactose c.steroid hormones d.small RNAs

In the slime mold species Dictyostelium discoideum, single-celled individuals gather in the migratory slug stage of development, in response to environmental cues. Which molecule is associated with this signaling?

A.Paleontologists typically select novel, unexplored areas to search for fossils as this is the best method to fill gaps in information that we see in the fossil record. b.Paleontologists typically focus on the sites that best match the geological and abiotic conditions in which fossilization may have occurred. c.Paleontologists are unlikely to be the first researchers to be searching for fossils from their organism of interest. Instead, they often choose sites where others have already uncovered related fossils. d.Paleontologists often use predictions derived from phylogenetic reconstruction, biogeography, or molecular genetics to explore a particular area.

It is very difficult to find the fossil remains of an entire organism. Which of the following is NOT a factor that paleontologists use when choosing sites to search for the best fossils?

a.Adding a large fraction of phospholipid molecules resulted in vesicles with lower phospholipid content; these cells tended to be reduced in size, conferring a selective advantage. b.Adding a large fraction of phospholipid molecules resulted in vesicles with higher phospholipid content; these cells tended to grow in size conferring a selective advantage. C.Adding a small fraction of phospholipid molecules resulted in vesicles with higher phospholipid content; these cells tended to grow in size conferring a selective advantage. d.Adding a small fraction of phospholipid molecules resulted in vesicles with lower phospholipid content; these cells tended to be reduced in size, conferring a selective advantage.

Itay Budin and Jack Szostak sought to understand how cell membranes composed of single-chain lipid molecules could possibly evolve to the more complex phospholipids seen in modern cell membranes (Budin and Szostak 2009). Which statement best summarizes their results?

a.Embryos display characteristics of embryos from species that preceded them on the scala naturae. B.General characteristics of embryos in closely related species develop before specific characteristics, and embryos of higher taxa do not resemble the adult form of ancestral lower-taxa species. c.Developmental stages of an organism progress through all the animal species that came before it on the scala naturae. d.Embryos of organisms progress through the adult stages of species that preceded them on the scala naturae.

Karl Ernst von Baer, a German naturalist, biologist, and embryologist, rejected both the scala naturae and the Meckel-Serres law. Instead, von Baer's law states which of the following?

a.When populations of a host species become geographically isolated from one another, the parasite populations have to adapt to new hosts, and this usually leads to speciation in the parasite as it adapts. b.When geographically isolated, both species experience divergence leading to a reduction in parasite load in the former host species as it becomes less habitable to the parasite. c.When populations of a parasite species become geographically isolated from one another, divergence results in speciation of the parasite species with subsequent colonization of new host species. D.When populations of a host species become geographically isolated from one another, the parasite populations that the host carries also become geographically isolated, leading to potential divergence of both species.

Kellogg (1896) and Fahrenholz (1909) both hypothesized that phylogenies of parasites and hosts often change in parallel. Why do we expect that?

social

Major transitions of Life Smith & Szarthmary: They listed at least 8 major transition of life on Earth - Compartments; Groups of genes; Genetic code; Eukaryotes; Sex, Cell differentiation; ________ colonies; Language.

a.Four pairs of legs develop in the thoracic region. b.Abdominal parts develop in the anterior. c.Antennae are replaced by wings. D.Antennae are replaced by legs.

One of the first sudied Hox gene mutations in Drosophilla was a mutation in the Antennapedia gene, which controls leg formation. This mutation is abbreviated as Antp. What is the phenotypic effect of this mutation?

a.Extinction of an endemic amphibian species results in global extinction of that species. B.The extinctions seem to be due to the increased predation of amphibians around the world. c.The current rate of extinction in amphibians is much higher than typical background extinction rates. d.One of the major factors driving these extinctions may be infectious disease.

Over the last few decades, there has been a major decline in amphibian populations worldwide, including the extinction of many amphibian species. Which of the following is FALSE regarding the amphibian decline?

a.cladogenesis B.punctuated equilibrium c.anagenesis d.phyletic gradualism

Paleontological studies on a lineage of bryozoans (whose fossils preserve many of their morphological characteristics) show a pattern of evolution with little or no change for long stretches of time. Occasionally, however, speciation occurred in a burst of change and diversification. This is an example of __________.

punctuated equilibrium

Pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change.

a.Natural selection will only favor those traits that help prey escape predation, resulting in an evolutionary arms race. b.Natural selection will only favor those traits that help predators capture their prey, resulting in a cessation of an evolutionary arms race. c.Natural selection will favor traits that help the prey species and negatively impact the predator species. D.Natural selection will favor traits in prey that increase the chance of escaping predation and traits in predators that increase their chance of capturing and killing prey, resulting in an evolutionary arms race.

Predator-prey interactions are one type of antagonistic coevolution. Which of the following traits would natural selection favor in these interactions?

a.Slime molds first appeared about 1 billion years ago. b.Dictyostelium discoideum is an important human pathogen. C.Slime molds provide clues as to how multicellularity may have evolved. d.Dictyostelium discoideum is one of the most abundant organisms on Earth.

Slime molds are unusual eukaryotes. They spend most of their life cycle as single-celled organisms, and yet under certain conditions, they form a slug-like multicellular stage and then a fruiting body composed of both somatic cells and reproductive spores. The best known species of slime mold is a soil dweller, Dictyostelium discoideum. Why is it important to study this and related species of slime molds?

A.amino acids b.single-stranded RNA molecules c.complex proteins d.ribosomes

Stanley Miller and Harold Urey developed and conducted experimental tests for a "prebiotic soup" model of the origin of life, which had been proposed a few decades earlier by Aleksandr Oparin and J.B.S. Haldane. What did Miller and Urey show could be synthesized abiotically?

a.This mass extinction occurred gradually over the course of millions of years, likely as a result of gradual changes in temperature, humidity, sea level, and other environmental properties. B.This mass extinction occurred as a result of an impact with an extraterrestrial body, such as an asteroid, as evidenced by the layer of clay demarcating the K-Pg boundary that contains iridium. c.The K-Pg mass extinction was the result of multiple volcanic eruptions in Siberia. d.The K-Pg mass extinction was the result of a large supernova that had exploded near Earth, producing radiation and triggering climate changes.

The famous Cretaceous-Paleogene (K-Pg) extinction occurred about 65 million years ago, close to the boundary between the Cretaceous and Paleogene periods, with profound effects on many different taxa, including the dinosaurs. Which of the following is widely accepted as the cause of this extinction?

a.a small protein b.a large lipid C.RNA d.DNA

The first geentic material on Earth was most likely ________.

a.Graphs B and C only b.Graph B c.Graph A D.Graph C

The following graphs show three different types of evolutionary change in a hypothetical clade. The y axis represents time, while the x axis represents a character (body size, in this example). Which of the following graphs represents an active evolutionary trend?

a.diffuse coevolution b.Batesian mimicry c.mosaic coevolution D.evolutionary arms race

The fossil record of the Sinistrofulgur-Mercenaria system shows that selection has favored an increased shell size and shell thickness in Mercenaria prey, which reduced the probability of it being eaten by Sinistrofulgur. Subsequently, the fossil record indicated there was an increase in size ofSinistrofulgur; larger Sinistrofulgur were more likely to be able to killMercenaria. What type of coevolutionary dynamic does this illustrate?$

polyploidization often occurred prior to or simultaneously with major evolutionary transitions and adaptive radiation of species, supporting the concept that polyploidy plays a predominant role in bursts of adaptive speciation. Polyploidy results in immediate genetic redundancy and represents, with the emergence of new gene functions, an important source of novelty. Along with recombination, gene mutation, transposon activity and chromosomal rearrangement, polyploidy and whole-genome duplication act as drivers of evolution and divergence in plant behaviour and gene function, enabling diversification, speciation and hence plant evolution.

We discussed polyploidy in the context of speciation. How might a particular plant lineage become a polyploidy? (Abstract)

A.Many of the clades that survive a period of mass extinction go extinct during the following geological time period. b.More susceptible clades die off very early and quickly at the beginning of mass extinction events. c.New clades that emerge following mass extinction quickly die out due to a lack of nutrients and other resources. d.Following mass extinctions, such as in the Permian, there is nothing to be found in many rock strata.

What is the meaning of the phrase "dead clade walking," which was coined by David Jablonski in 2002?

a.mutualistic coevolution B.antagonistic coevolution c.cospeciation d.none of these

What type of coevolution produces an evolutionary arms race between a predator and its prey or a parasite and its host, which may go on indefinitely, producing a wide array of adaptations?

a.NH3 B.O2 c.H2 d.CH4

Which gas was most likely the LEAST abundant in early Earth's atmosphere?$

a.Homeotic genes encode proteins that control the cellular environment in a differentiated cell tissue. B.Homeotic genes are "master-switch" genes that control other genes in a set sequence and thereby affect cell size, shape, division, and the positioning of the cells within the organism. c.Homeotic genes are DNA sequences that turn off, but not on, the expression of other genes and are controlled by "master-switch" genes. d.Homeotic genes are DNA sequences that turn on, but not off, the expression of other genes and are controlled by "master-switch" genes.

Which of the following correctly defines "homeotic genes"?$

a.Chloroplasts are derived from ancient free-living photosynthetic cyanobacteria. b.Cyanobacteria are related to algal plastids. c.RNA shows that the chloroplasts of plants are closely related to cyanobacteria. D.Chloroplasts are derived from ancient free-living photosynthetic archaebacteria.

Which of the following is FALSE regarding the evolution of chloroplasts?

a.The evolution of multicellularity represents one of the major transitions in the history of life on Earth. b.The transition has occurred independently many times, in many taxa, over evolutionary history. c.In the early steps toward an obligate multicellularity, cells may have often joined together temporarily and then disbanded. D. The transition from unicellular to multicellular life occurred only once in evolutionary history, giving rise to all multicellular organisms today.

Which of the following is FALSE regarding the evolution of multicellularity?

a.Extinctions are not very common in endemic species. b.There is no difference between global and endemic species when it comes to the study of extinction. C.It is much easier to study extinction in endemic species because such local extinction becomes synonymous with global extinction for that species. d.It is much better to focus on species that live throughout the world and prevent their extinction.

Which of the following is correct regarding the endemic species as they relate to the study of background extinction?

a.nucleic acids b.polypeptides C.fatty acids d.steroid hormones

Which of the following molecules involved in membrane structure was likely favored by natural selection in the evolution of early cells?

a.The acronym stands for "last universal common ancestor." B.It refers to a single, ancestral organism. c.It represents a base to the tree of life. d.It represents a phylogenetic event horizon.

Which of the following statements about LUCA is NOT correct?

A.The self-replicating ribozymes that had more efficient catalytic activities would soon began to dominate their populations. b.In the self-replicating ribozymes, variation in the rate of replication was not heritable. c.Truly self-replicating enzymes had not evolved in Earth's early environment. d.Ribozymes produced true protein-based enzymes.

Which of the following statements about the Lincoln and Joyce experiment on self-replicating ribozymes is most likely correct?

a. When the mouse Hox-2.2 gene is experimentally inserted into the fruit fly genome and expressed in the head of developing fruit flies, adults produce legs in place of antennae. B.Hox genes can be transplanted between vertebrate species, but not from vertebrate to invertebrate or vice versa. c.Homeobox regions of the Hox genes allow the transcription factor of one species to function in the other species. d.When a Hox gene product from an appropriate chromosomal region in chickens is inserted into a fruit fly embryo, it results in normal regulation of the fruit fly development.

Which of the following statements is FALSE about Hox genes experiments?

a.Replication of RNA is too fast to be favored by natural selection. B.DNA is a more stable molecule because deoxyribose is less reactive than is ribose. c.DNA replication systems do not have the proofreading capabilities that are usually present in RNA replication. d.The double stranded structure of DNA has a much greater potential for interaction with outside molecules.

Which of the following statements regarding the benefit of making the switch from an RNA- to a DNA-based genetic system during the evolution of life is correct?

a. The body size of the largest living organisms has increased over evolutionary time. b. The complexity of multicellular organisms, as measured by the number of cell types, has increased over evolutionary time. C. Natural selection always results in an increase of complexity over evolutionary time. d. Modern bacteria and archaea are not always more complex than their ancestors that lived before the origin of multicellular life.

Which of the following statements regarding the complexity of living organisms is FALSE?

A. formation of the solar system including Earth b. origin of self-replicating molecules capable of heredity c. evolution of sexual reproduction d. evolution of multicellular organisms from single-celled ancestors

Which one of the following is NOT a major transition in the evolution of life, according to biologists John Maynard Smith and Eörs Szathmary?

a.Cech and Altman B.Oparin and Haldane c.Miller and Urey d.Wallace and Lyell

Which two scientists elaborated on Darwin's idea of the "warm little pond" and formulated the "prebiotic soup hypothesis" as the first hypothesis for the abiotic origin of life on Earth?

a.The evolution of multicellularity made it impossible for horizontal gene transfer to occur in modern organisms. B.As cells became more complicated, they also became more integrated, less modular and less likely to take up new genes by horizontal gene transfer. c.As cells became more simplified, they became more streamlined and efficient in functioning, so there was no selective advantage to the uptake of additional genetic material via horizontal gene transfer. d.The evolution from an RNA-based world to a DNA-based world made it impossible for horizontal gene transfer to occur in modern organisms.

Why did the role of horizontal gene transfer ultimately become diminished over evolutionary time?

Oxygen

_______. This element, at least in the form of two covalently bonded atoms, was rare in the Earth's atmosphere for the first 2.4 billion years of Earth history.

Dinosaurs

________. Contemporary phylogenetic analyses have shown that Birds are part of this group, most of whose members are extinct, and have been for - 65 million years.

Hox

________. Our understanding of diversification associated with developmental patterns has been revolutionized by the discovery of: A. 16s rRNA; B. Hox genes; C. Horizontal Gene Transfer (HGT); D. Widespread Gene Duplication.

diffuse coevolution

a network of species undergoes reciprocal evolutionary change through natural selection

mosaic coevolution

a situation in which the same two species interact mutualistically in some communities but antagonistically in others

phyletic gradualism

a theory arguing that one species gradually transforms itself into a new species over time, yet the actual boundary between species can never be detected and can only be drawn arbitrarily

Meckel-Serres Law

embryos display characteristics of embryos from species that preceded them

Anagenesis

single species evolves into a different species

Von Baer's Law

the features that distinguish between different species tend to arise later in development

Cladogenesis

the formation of a new group of organisms or higher taxon by evolutionary divergence from an ancestral form.