BSC-116-001 Chapter 26

12 September 2022
4.7 (114 reviews)
42 test answers
question
Animals that possess homologous structures probably _____. A. have increased genetic diversity B. evolved from the same ancestor C. are not related D. are the result of convergent evolution E. are the result of similar environmental pressures in different evolutionary lineages
answer
B. evolved from the same ancestor Homologous structures are similar because of common ancestry.
question
By definition a clade is _____. A. parsimonious B. polyphyletic C. paraphyletic D. analogous E. monophyletic
answer
E. monophyletic A clade is defined as a group that includes an ancestral species and all of its descendants.
question
Fossil evidence indicates that some dinosaurs had feathers. If birds are indeed descended from dinosaurs, feathers are what kind of character? A. analogous character B. shared derived character C. polyphyletic character D. cladistic character E. shared ancestral character
answer
E. shared ancestral character A shared ancestral character is one that originated in an ancestor of the taxon. In this case it appears that feathers originated in some dinosaur lineages and were passed down to birds.
question
What process actually increases the number of genes in an organism's genome? What process actually increases the number of genes in an organism's genome? A.mutation B.parsimony C. gene duplication D. cladistics E. independent assortment
answer
C. gene duplication Mutations that lead to duplications actually increase the number of genes in a genome. When an organism has two copies of a gene, one can perform its function while the other is free to accumulate mutations to the point that it may take on a new and advantageous function.
question
Why do researchers use rRNA in investigations of relationships between taxa that diverged hundreds of millions of years ago? A. rRNA is traditionally the nucleic acid chosen for recent comparisons. B. rRNA is never the nucleic acid chosen for comparisons. C. rRNA cannot mutate. D. DNA coding for rRNA changes relatively slowly. E. rRNA mutates rapidly.
answer
D. DNA coding for rRNA changes relatively slowly.
question
Molecular clocks are based on the idea that _____. A.directional selection occurs at a constant rate B. molecules resonate at a certain frequency that can be measured C. on average neutral mutations arise at a constant rate D. mutations occur once every generation E. advantageous mutations arise at a constant rate
answer
C. on average neutral mutations arise at a constant rate The idea of a molecular clock rests on the assumption that neutral mutations can arise and become fixed in populations. The rate of occurrence of these mutations is not affected by natural selection, so it is assumed that the rate is relatively constant over time.
question
Which process occurred frequently in the early history of the three domains on Earth, and makes determining phylogenetic relationships of that time difficult? A. horizontal gene transfer B. alternative RNA splicing C. meiosis D. binary fission E. mitosis
answer
A. horizontal gene transfer Horizontal gene transfer permits gene flow from one organism's genome to another organism's genome, It occurs commonly between prokaryotes of different species, and even between prokaryotes and eukaryotes.
question
Which observation supports the position of eukaryotes at the convergence of the "ring of life"? A. The nuclear genome of eukaryotes contains genes from archaeans and from bacteria. B. Introns are rare in both bacteria and archaeans. C. Circular chromosomes are present in both bacteria and archaeans. D. Eukaryotes and archaeans both lack peptidoglycan in their cell walls. E. Only eukaryotes perform mitosis.
answer
A. The nuclear genome of eukaryotes contains genes from archaeans and from bacteria. A leading hypothesis proposes that eukaryotes are the result of fusion involving a bacterium and an archaean, thereby explaining the presence of both kinds of genes.
question
Prokaryotic cells are found in the domain(s) _____. A. Bacteria and Archaea B. Bacteria and Eukarya C. Bacteria and Protista D. Bacteria E. Protista and Archaea
answer
A. Bacteria and Archaea Both of these domains are composed of prokaryotic cells.
question
In the five-kingdom system, prokaryotes are placed in the kingdom _____. A. Protista B. Animalia C. Fungi D. Plantae E. Monera
answer
E. Monera All monerans are prokaryotes.
question
A human is classified in domain _____ and kingdom _____. A. Eukarya ... Fungi B. Eukarya ... Protista C. Eukarya ... Plantae D. Eukarya ... Animalia E. Bacteria ... Archaea
answer
D. Eukarya ... Animalia Humans are animals, and animals are eukaryotes.
question
A rose bush is classified in domain _____ and kingdom _____. A. Eukarya ... Fungi B. Eukarya ... Protista C. Eukarya ... Plantae D. Eukarya ... Animalia E. Bacteria ... Archaea
answer
C. Eukarya ... Plantae Rose bushes are plants.
question
In the five-kingdom system, which kingdom consists primarily of unicellular eukaryotes? A. Fungi B. Protista C. Plantae D. Animalia E. Monera
answer
B. Protista Protists are mostly unicellular eukaryotes, though they also include multicellular algae.
question
In the two-kingdom system, why were fungi classified in the kingdom Plantae? A. They are sedentary. B. They are heterotrophs. C. They lack cell walls. D. They are unicellular. E. They are autotrophs.
answer
A. They are sedentary. This is why fungi were placed in the same kingdom as plants.
question
There is(are) _____ eukaryotic domain(s). A. one B. two C. three D. four E. five
answer
A. one The only eukaryotic domain is the domain Eukarya.
question
This figure shows a phylogenetic tree of birds and their close relatives. Identify the monophyletic taxon. A. Birds and the common ancestor of dinosaurs and birds B. Birds and crocodiles and their common ancestor C. Birds and dinosaurs and their common ancestor
answer
C. Birds and dinosaurs and their common ancestor This grouping is monophyletic becuase it includes the common ancestor and all of its descendents. Read about monophyletic groups called clades.
question
Homology
answer
Similarity due to shared ancestry
question
Analogy
answer
Similarity due to convergent evolution
question
Clade
answer
Is a monophyletic grouping that includes an ancestral species and all of its descendants
question
Orthologous genes
answer
Are homologous genes found in different species as a result of speciation
question
Paralogous genes
answer
are homologous genes within a species that result from gene duplication
question
The three great domains
answer
1.) Bacteria 2.) Archae 3.) Eukarya
question
In comparison of birds and mammals, the condition of having four limbs is A. a shared ancestral character. B. a shared derived character. C. a character useful for distinguishing birds from mammals D. an example of analogy rather than homology
answer
A. a shared ancestral character.
question
To apply parsimony to constructing a phylogenetic tree, A. choose a tree that assumes all evolutionary changes are equally probable. B. choose a tree in which the branch points are based on as many shared derived characters as possible. C. choose the tree the represents the fewest evolutionary changes, in either DNA sequences or morphology. D. choose the tree with the fewest branch points.
answer
C. choose the tree the represents the fewest evolutionary changes, in either DNA sequences or morphology.
question
Three living species X,Y, and Z share a common ancestor T, as do distinct species U and V. A grouping that consists of species T, X, Y, and Z (but not U or V) makes up A. a monophyletic taxon. B. an ingroup, with species U as the outgroup. C. a paraphyletic group. D. a polyphyletic group.
answer
C. a paraphyletic group.
question
If you were to build a phylogenetic tree of cats, which of the following would be the best outgroup? A. wolf B. domestic cat C. lion D. leopard
answer
A. wolf
question
Phylogeny
answer
The evolutionary history of a species or group of species.
question
Systematics
answer
A discipline focused on classifying organisms and determining their evolutionary relationships.
question
The taxonomic / Linnaean system
answer
Domain -> Kingdom -> Phylum -> Class -> Order -> Family -> Genus -> Species
question
Branch Point
answer
Represents the divergence of two evolutionary lineages from a common ancestor.
question
Sister taxa
answer
Groups of organisms that share an immediate common ancestor.
question
Basal taxon
answer
Refers to a lineage that diverges early in the history of a group.
question
Polytomy
answer
A branch point from which more than two descendant groups emerge.
question
Homoplasies
answer
Analogous structures that arose independently are also called homoplasies.
question
Cladistics
answer
An approach to systematics where ancestry is the primary criterion used to classify organisms.
question
Paraphyletic
answer
A group which consists of an ancestral species and some, but not all, of its descendants.
question
Polyphyletic
answer
A group which includes distantly related species but does not include their most common ancestor.
question
Shared ancestral character
answer
A character that originated in an ancestor of the taxon.
question
Shared derived character
answer
An evolutionary novelty unique to a clade.
question
Outgroup
answer
Is a species or group of species from an evolutionary lineage that is known to have diverged before the lineage that includes the species we are studying.
question
Ingroup
answer
The lineage that includes the species we are studying.
question
Molecular clock
answer
An approach for measuring the absolute time of evolutionary change based on the observation that some genes and other regions of genomes appear to evolve at constant rates.
1 of 42

Unlock all answers in this set

Unlock answers (38)
question
Animals that possess homologous structures probably _____. A. have increased genetic diversity B. evolved from the same ancestor C. are not related D. are the result of convergent evolution E. are the result of similar environmental pressures in different evolutionary lineages
answer
B. evolved from the same ancestor Homologous structures are similar because of common ancestry.
question
By definition a clade is _____. A. parsimonious B. polyphyletic C. paraphyletic D. analogous E. monophyletic
answer
E. monophyletic A clade is defined as a group that includes an ancestral species and all of its descendants.
question
Fossil evidence indicates that some dinosaurs had feathers. If birds are indeed descended from dinosaurs, feathers are what kind of character? A. analogous character B. shared derived character C. polyphyletic character D. cladistic character E. shared ancestral character
answer
E. shared ancestral character A shared ancestral character is one that originated in an ancestor of the taxon. In this case it appears that feathers originated in some dinosaur lineages and were passed down to birds.
question
What process actually increases the number of genes in an organism's genome? What process actually increases the number of genes in an organism's genome? A.mutation B.parsimony C. gene duplication D. cladistics E. independent assortment
answer
C. gene duplication Mutations that lead to duplications actually increase the number of genes in a genome. When an organism has two copies of a gene, one can perform its function while the other is free to accumulate mutations to the point that it may take on a new and advantageous function.
question
Why do researchers use rRNA in investigations of relationships between taxa that diverged hundreds of millions of years ago? A. rRNA is traditionally the nucleic acid chosen for recent comparisons. B. rRNA is never the nucleic acid chosen for comparisons. C. rRNA cannot mutate. D. DNA coding for rRNA changes relatively slowly. E. rRNA mutates rapidly.
answer
D. DNA coding for rRNA changes relatively slowly.
question
Molecular clocks are based on the idea that _____. A.directional selection occurs at a constant rate B. molecules resonate at a certain frequency that can be measured C. on average neutral mutations arise at a constant rate D. mutations occur once every generation E. advantageous mutations arise at a constant rate
answer
C. on average neutral mutations arise at a constant rate The idea of a molecular clock rests on the assumption that neutral mutations can arise and become fixed in populations. The rate of occurrence of these mutations is not affected by natural selection, so it is assumed that the rate is relatively constant over time.
question
Which process occurred frequently in the early history of the three domains on Earth, and makes determining phylogenetic relationships of that time difficult? A. horizontal gene transfer B. alternative RNA splicing C. meiosis D. binary fission E. mitosis
answer
A. horizontal gene transfer Horizontal gene transfer permits gene flow from one organism's genome to another organism's genome, It occurs commonly between prokaryotes of different species, and even between prokaryotes and eukaryotes.
question
Which observation supports the position of eukaryotes at the convergence of the "ring of life"? A. The nuclear genome of eukaryotes contains genes from archaeans and from bacteria. B. Introns are rare in both bacteria and archaeans. C. Circular chromosomes are present in both bacteria and archaeans. D. Eukaryotes and archaeans both lack peptidoglycan in their cell walls. E. Only eukaryotes perform mitosis.
answer
A. The nuclear genome of eukaryotes contains genes from archaeans and from bacteria. A leading hypothesis proposes that eukaryotes are the result of fusion involving a bacterium and an archaean, thereby explaining the presence of both kinds of genes.
question
Prokaryotic cells are found in the domain(s) _____. A. Bacteria and Archaea B. Bacteria and Eukarya C. Bacteria and Protista D. Bacteria E. Protista and Archaea
answer
A. Bacteria and Archaea Both of these domains are composed of prokaryotic cells.
question
In the five-kingdom system, prokaryotes are placed in the kingdom _____. A. Protista B. Animalia C. Fungi D. Plantae E. Monera
answer
E. Monera All monerans are prokaryotes.
question
A human is classified in domain _____ and kingdom _____. A. Eukarya ... Fungi B. Eukarya ... Protista C. Eukarya ... Plantae D. Eukarya ... Animalia E. Bacteria ... Archaea
answer
D. Eukarya ... Animalia Humans are animals, and animals are eukaryotes.
question
A rose bush is classified in domain _____ and kingdom _____. A. Eukarya ... Fungi B. Eukarya ... Protista C. Eukarya ... Plantae D. Eukarya ... Animalia E. Bacteria ... Archaea
answer
C. Eukarya ... Plantae Rose bushes are plants.
question
In the five-kingdom system, which kingdom consists primarily of unicellular eukaryotes? A. Fungi B. Protista C. Plantae D. Animalia E. Monera
answer
B. Protista Protists are mostly unicellular eukaryotes, though they also include multicellular algae.
question
In the two-kingdom system, why were fungi classified in the kingdom Plantae? A. They are sedentary. B. They are heterotrophs. C. They lack cell walls. D. They are unicellular. E. They are autotrophs.
answer
A. They are sedentary. This is why fungi were placed in the same kingdom as plants.
question
There is(are) _____ eukaryotic domain(s). A. one B. two C. three D. four E. five
answer
A. one The only eukaryotic domain is the domain Eukarya.
question
This figure shows a phylogenetic tree of birds and their close relatives. Identify the monophyletic taxon. A. Birds and the common ancestor of dinosaurs and birds B. Birds and crocodiles and their common ancestor C. Birds and dinosaurs and their common ancestor
answer
C. Birds and dinosaurs and their common ancestor This grouping is monophyletic becuase it includes the common ancestor and all of its descendents. Read about monophyletic groups called clades.
question
Homology
answer
Similarity due to shared ancestry
question
Analogy
answer
Similarity due to convergent evolution
question
Clade
answer
Is a monophyletic grouping that includes an ancestral species and all of its descendants
question
Orthologous genes
answer
Are homologous genes found in different species as a result of speciation
question
Paralogous genes
answer
are homologous genes within a species that result from gene duplication
question
The three great domains
answer
1.) Bacteria 2.) Archae 3.) Eukarya
question
In comparison of birds and mammals, the condition of having four limbs is A. a shared ancestral character. B. a shared derived character. C. a character useful for distinguishing birds from mammals D. an example of analogy rather than homology
answer
A. a shared ancestral character.
question
To apply parsimony to constructing a phylogenetic tree, A. choose a tree that assumes all evolutionary changes are equally probable. B. choose a tree in which the branch points are based on as many shared derived characters as possible. C. choose the tree the represents the fewest evolutionary changes, in either DNA sequences or morphology. D. choose the tree with the fewest branch points.
answer
C. choose the tree the represents the fewest evolutionary changes, in either DNA sequences or morphology.
question
Three living species X,Y, and Z share a common ancestor T, as do distinct species U and V. A grouping that consists of species T, X, Y, and Z (but not U or V) makes up A. a monophyletic taxon. B. an ingroup, with species U as the outgroup. C. a paraphyletic group. D. a polyphyletic group.
answer
C. a paraphyletic group.
question
If you were to build a phylogenetic tree of cats, which of the following would be the best outgroup? A. wolf B. domestic cat C. lion D. leopard
answer
A. wolf
question
Phylogeny
answer
The evolutionary history of a species or group of species.
question
Systematics
answer
A discipline focused on classifying organisms and determining their evolutionary relationships.
question
The taxonomic / Linnaean system
answer
Domain -> Kingdom -> Phylum -> Class -> Order -> Family -> Genus -> Species
question
Branch Point
answer
Represents the divergence of two evolutionary lineages from a common ancestor.
question
Sister taxa
answer
Groups of organisms that share an immediate common ancestor.
question
Basal taxon
answer
Refers to a lineage that diverges early in the history of a group.
question
Polytomy
answer
A branch point from which more than two descendant groups emerge.
question
Homoplasies
answer
Analogous structures that arose independently are also called homoplasies.
question
Cladistics
answer
An approach to systematics where ancestry is the primary criterion used to classify organisms.
question
Paraphyletic
answer
A group which consists of an ancestral species and some, but not all, of its descendants.
question
Polyphyletic
answer
A group which includes distantly related species but does not include their most common ancestor.
question
Shared ancestral character
answer
A character that originated in an ancestor of the taxon.
question
Shared derived character
answer
An evolutionary novelty unique to a clade.
question
Outgroup
answer
Is a species or group of species from an evolutionary lineage that is known to have diverged before the lineage that includes the species we are studying.
question
Ingroup
answer
The lineage that includes the species we are studying.
question
Molecular clock
answer
An approach for measuring the absolute time of evolutionary change based on the observation that some genes and other regions of genomes appear to evolve at constant rates.