The analytical approach to understanding the diversity and relatedness of both extant and extinct organisms is called _____.
A)systematics
B)evolution
C)taxonomy
D)binomial nomenclature
E)phylogeny
A)systematics
Systematists study morphological and behavioral resemblances as well as molecular similarities and differences to devise theories about relationships.
What is the focus of the branch of biology called taxonomy?
A)evolution
B)the classification of life-forms by their similarities and differences
C)genetics
D)the history of the field of biology
E)the environment
B) the classification of life-forms by their similarities and differences.
This is exactly what the study of taxonomy seeks to accomplish.
The binomial system assigns to each organism a unique name that describes its _____.
A)order and family
B)body plan and habitat
C)genus and species
D)family and species
E)evolutionary history
C)genus and species
Each species is assigned a two-part Latin name, or binomial. The first word is the genus and the second word is the species. Species that are very similar are grouped into the same genus.
The two-part format of the scientific name, referred to as binomial, ensures that _____.
A)each species is assigned a unique name
B)each species has a name that is understandable regardless of language barriers among scientists
C)systematists can easily specify the closest relatives of any species
D)all of the above
E)none of the above
D)all of the above
Scientific names avoid ambiguity.
All the members of which one of the following groups have the greatest number of characteristics in common?
A)class
B)genus
C)kingdom
D)phylum
e)species
e)species
A taxon _____.
A)is a formal grouping at any given level
B)is a formal grouping in any level from phylum to species
C)is a clade
D)is a species
E)of one type of organism at one level is comparable to another type of organism at the same level.
A)is a formal grouping at any given level
A taxon is a formal grouping of organisms at any given level, such as species, genus, or phylum.
Two worms in the same class must also be grouped in the same _____.
A)order
B)phylum
C)genus
D)family
E)species
B)phylum
Class is less inclusive than phylum; organisms that are in the same class are also in the same phylum.
Species A and species B are in the same phylum. Species A and species C, but not species B, are in the same order. From this information you can conclude that _____.
A)species C could be in the same class as species A and B
B)species A and species B are in the same family
C)species B and species C share a less recent ancestor than do species A and B
D)all three species are members of the same genus
E)all three species are not members of the same phylum
A)species C could be in the same class as species A and B
If species A and species C are in the same order, then they must also be in the same class. Since you know that species A and species B are in the same phylum, it is possible that they are in the same class, but different orders.
What does a branch point in a phylogenetic tree represent?
A)A branch point represents a split between two phyla.
B)A branch point represents a gene duplication event.
C)A branch point represents a place where one species branches off from another.
D)A branch point represents the absolute time at which two evolutionary lineages split from a common ancestor.
E)A branch point represents a point at which two evolutionary lineages split from a common ancestor.
E)A branch point represents a point at which two evolutionary lineages split from a common ancestor.
A branch point shows evolutionary relationships as a dichotomy.
Which one of the following methods to establish phylogenetic relationships among organisms has been developed most recently?
A)comparing morphology (shape and structure)
B)comparing physiology (the functioning of structures and systems)
C)comparing the component sequences of proteins and nucleic acids
D)comparing behavioral patterns
E)comparing embryonic development
C)comparing the component sequences of proteins and nucleic acids
The comparison of nucleic acids and proteins has become a powerful addition to the other comparative methods that systematists use to measure evolutionary relationships among species.
The wings of a hummingbird and a bee are _____.
A)homologous
B)phylogenetic
C)analogous
D)binomial
E)taxonomic
C)analogous
Structures that are similar as a result of convergent evolution are referred to as analogous structures.
Which of the following would be the least useful in determining the relationships among various species?
A)a comparison of DNA base sequences
B)homologous structures
C)fossils
D)amino acid sequences of proteins
E)analogous structures
E)analogous structures
Analogous structures are the result of convergent evolution and may not reflect the relationships among the species that share them.
Researchers can use molecular homologies to _____.
A)estimate how long ago the common ancestor lived
B)reveal the amount of mutations in a particular sequence that have occurred between the species since they diverged from a common ancestor
C)hypothesize about the morphological structures of a common ancestor
D)hypothesize about the behavior of a common ancestor
E)all of the above
B)reveal the amount of mutations in a particular sequence that have occurred between the species since they diverged from a common ancestor
Over long periods of time, insertions and deletions accumulate.
A phylogenetic tree of bird families constructed by cladistic analysis would be a hypothesis about which of the following?
A)characteristics shared by all bird families
B)evolutionary relationships among bird families
C)families that look most alike
D)analogous structures shared by various species
E)relative ages of living species of birds
B)evolutionary relationships among bird families
Phylogenetic trees are constructed to reflect the evolutionary relationships among organisms.
Looking at the table and phylogenetic tree in Figure 26.11, which of the following is a true statement?
A)Four walking legs is a shared ancestral character in salamanders and a shared derived character in turtles.
B)Four walking legs is a shared derived character in salamanders and a shared ancestral character in turtles.
C)Hinged jaws are derived from lampreys.
D)Four walking legs is a shared derived character in leopards.
E)The amniotic egg is a shared derived character in salamanders.
B)Four walking legs is a shared derived character in salamanders and a shared ancestral character in turtles.
Four walking legs first appears in amphibians and was then inherited by reptiles.
Many researchers who study the kingdom Protista argue that all of these organisms should not be placed in the same kingdom, because these organisms could not have evolved from a common ancestor. In other words, they argue that the kingdom Protista is _____.
A)polyphyletic
B)paraphyletic
C)monophyletic
D)heterophyletic
E)none of the above
A)polyphyletic
A taxon is polyphyletic if its members are derived from ancestors that are not common to all members.
Using cladistic analysis, a taxonomist wishes to construct a phylogenetic tree showing the relationships among various species of mammals. Which of the following would be the least useful for this purpose?
A)descriptions of various types of limbs (wings, legs, flippers, etc.)
B)the fact that all mammals have hair
C)data about skull bones
D)the fact that teeth vary among types of mammals
E)DNA base sequences
B)the fact that all mammals have hair
As a shared derived character, hair cannot be used to determine the phylogeny of mammals.
Which statement below is true about an outgroup?
A)Outgroup comparison is based on the assumption that homologies present in both the outgroup and ingroup must be derived characters.
B)The outgroup would be found at one of the highest branches of a phylogenetic tree.
C)The outgroup and ingroup display a mixture of shared and derived characters.
D)The outgroup should be less closely related to any members of the ingroup than they are to each other.
E)none of the above
D)The outgroup should be less closely related to any members of the ingroup than they are to each other.
The outgroup should be known to be less closely related than any ingroup members are to each other based on other evidence such as paleontology, embryonic development, and gene sequences.
Phylogenetic trees with branch lengths proportional to time can be used to _____.
A)estimate the amount of time since two groups diverged from a common ancestor
B)represent the chronological time that has passed since two groups diverged from a common ancestor
C)reflect the number of evolutionary changes that have taken place in a lineage
D)reflect the rate of evolutionary change
E)tie polyphyletic clades to a common ancestor
B)represent the chronological time that has passed since two groups diverged from a common ancestor
In this type of tree, called an ultrametric tree, the branching pattern is the same as in a normal phylogenetic tree, but all the branches that can be traced from the common ancestor to the present are of equal length.
Which statement below is true of parsimonious trees?
A)The best tree requires the fewest evolutionary events to have occurred in the form of shared derived characters.
B)The best tree requires the fewest evolutionary events to have occurred in the form of shared ancestral characters.
C)Given the rules of how morphological traits change over time, a tree can be found that reflects the most likely sequence of evolutionary events.
D)Given the rules of how DNA changes over time, a tree can be found that reflects the most likely sequence of evolutionary events.
E)Trees can be constructed that are parsimonious or the most likely, but not both at the same time.
A)The best tree requires the fewest evolutionary events to have occurred in the form of shared derived characters.
This statement is true regarding trees based on morphological characters. For phylograms based on DNA, the most parsimonious tree requires the smallest number of base changes in DNA.
Birds and mammals have a four-chambered heart, but reptiles have a three-chambered heart. How does this fact affect the construction of phylogenetic trees for these groups?
A)it shows that the common ancestor of birds and mammals must have had a four-chambered heart.
B)This represents a problem with the principle of parsimony, rather than a problem with the analogy-homology issue.
C)The most likely tree is always the most parsimonious.
D)The most likely tree is not always the most parsimonious.
E)none of the above
D)The most likely tree is not always the most parsimonious.
If you wanted to determine the lineage of plants that have evolved on a relatively young archipelago—approximately 15,000 years old—what type of nucleic acid should you compare?
A)mRNA
B)rRNA
C)mtDNA
D)tRNA
E)miRNA
C)mtDNA
Mitochondrial DNA (mtDNA) evolves rapidly and can be used to explore more recent evolutionary events.
Paralogous genes _____.
A)are passed from generation to generation in a straight line
B)result from gene duplication
C)can only diverge after speciation has taken place
D)are responsible for the differences in beta hemoglobin in humans and mice
E)cannot diverge in the same gene pool
B)result from gene duplication
Paralogous genes are found in more than one copy in the same genome. An example is the olfactory receptor genes in vertebrates, which have undergone many gene duplications.
What is the evolutionary significance of paralogous genes?
A)They increase the size of the genome and provide more opportunity for the evolution of novel characteristics.
B)They give the absolute time that the gene duplication occurred.
C)They give the absolute time that two species diverged.
D)The fact that many paralogous genes are found in vastly different organisms emphasizes the many biochemical and developmental pathways shared by all organisms.
E)none of the above
A)They increase the size of the genome and provide more opportunity for the evolution of novel characteristics.
What is the evolutionary significance of orthologous genes?
A)They increase the size of the genome and provide more opportunity for the evolution of novel characteristics.
B)They are passed from generation to generation in a straight line, and as such they change very little.
C)The high percentage of orthologous genes found in vastly different organisms emphasizes the many biochemical and developmental pathways shared by all organisms.
D)They always provide the evolutionary explanation with the maximum parsimony.
E)all of the above
C)The high percentage of orthologous genes found in vastly different organisms emphasizes the many biochemical and developmental pathways shared by all organisms.
The prevalence of orthologous genes supports the idea of descent with modification.
Which is an assumption of the neutral theory?
A)Much evolutionary change in genes and proteins has no effect on fitness and therefore is not influenced by Darwinian selection.
B)Most harmful mutations are removed from a population quickly.
C)Differences in the rate of the clock in different genes are a function of how important each gene is.
D)If a particular sequence of amino acids is critical for survival, most new mutations will be harmful and fewer will be neutral. These genes will change slowly over time.
E)all of the above
A)Much evolutionary change in genes and proteins has no effect on fitness and therefore is not influenced by Darwinian selection.
This theory states that these changes are mostly neutral-neither adaptive nor detrimental.
The idea of using molecules as clocks to time evolutionary events is very attractive, but there are many problems in actually applying the technique. What seems to be the best way to get reliable results?
A)It is important to use a gene that has been affected by natural selection to ensure that evolution will be observed.
B)It is important to use as many genes as possible. With this approach, fluctuations in evolutionary rate will tend to average out.
C)It is important to use one gene in which the changes are clearly neutral.
D)It is best to use a gene that is essential to survival because they change more slowly.
E)all of the above
B)It is important to use as many genes as possible. With this approach, fluctuations in evolutionary rate will tend to average out.
By applying a molecular clock, researchers at Los Alamos National Laboratory have proposed that the first HIV-1 M invasion into humans occurred in the _____.
A)1830s
B)1890s
C)1930s
D)1950s
E)1980s
C)1930s
This is the point in time when some scientists estimate that HIV jumped from simians to humans.
To which domain is the domain Eukarya (the domain to which humans belong) most closely related?
A)Bacteria
B)Fungi
C)Archaea
D)Protista
E)It is not clear whether eukaryotes are more closely related to bacteria or archaea.
E)It is not clear whether eukaryotes are more closely related to bacteria or archaea.
Universal phylogenetic trees built from different genes sometimes give inconsistent results. What basic assumption on which phylogenetic trees are based has probably been violated during the history of life?
A)Analogous traits come about because of convergent evolution.
B)Homologous traits come about because of common ancestry.
C)The greater the difference in gene sequences, the longer two species have diverged.
D)Genes are often passed from one organism to another without the occurrence of reproduction.
E)Genes are passed vertically from one generation to the next.
E)Genes are passed vertically from one generation to the next.