Question 1

The most important feature that permits a gene to act as a molecular clock is

Accepted Answer

A) having a large number of base pairs. 
B) having a larger proportion of exonic DNA than of intronic DNA. 
C) having a reliable average rate of mutation. 
D) its recent origin by a gene-duplication event. 
E) its being acted upon by natural selection. 
A) having a large number of base pairs. 
B) having a larger proportion of exonic DNA than of intronic DNA. 
C) having a reliable average rate of mutation. 
D) its recent origin by a gene-duplication event. 
E) its being acted upon by natural selection.

Question 2

The following questions refer to the information below.
A researcher compared the nucleotide sequences of a homologous gene from five different species of mammals with the homologous human gene. The sequence homology between each species' version of the gene and the human gene is presented as a percentage of similarity.
 $$\begin{array} { l c } 
\text { Species } & \text { Percentage } \
\hline \text { Chimpanzee } & 99.7 \
\text { Orangutan } & 98.6 \
\text { Baboon } & 97.2 \
\text { Rhesus Monkey } & 96.9 \
\text { Rabbit } & 93.7
\end{array}$$

-The reason that paralogous genes can diverge from each other within the same gene pool, whereas orthologous genes diverge only after gene pools are isolated from each other, is that

Accepted Answer

A) having multiple copies of genes is essential for the occurrence of sympatric speciation in the wild. 
B) paralogous genes can occur only in diploid species; thus, they are absent from most prokaryotes. 
C) polyploidy is a necessary precondition for the occurrence of sympatric speciation in the wild. 
D) having an extra copy of a gene permits modifications to the copy without loss of the original gene product. 
A) having multiple copies of genes is essential for the occurrence of sympatric speciation in the wild. 
B) paralogous genes can occur only in diploid species; thus, they are absent from most prokaryotes. 
C) polyploidy is a necessary precondition for the occurrence of sympatric speciation in the wild. 
D) having an extra copy of a gene permits modifications to the copy without loss of the original gene product.

Question 3

The following questions refer to the hypothetical patterns of taxonomic hierarchy shown in Figure 26.2.

-If this figure is an accurate depiction of relatedness, then which taxon is unacceptable, based on cladistics?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 5 
A) 1 
B) 2 
C) 3 
D) 4 
E) 5

Question 4

The following questions refer to the information below.
A researcher compared the nucleotide sequences of a homologous gene from five different species of mammals with the homologous human gene. The sequence homology between each species' version of the gene and the human gene is presented as a percentage of similarity.
 $$\begin{array} { l c } 
\text { Species } & \text { Percentage } \
\hline \text { Chimpanzee } & 99.7 \
\text { Orangutan } & 98.6 \
\text { Baboon } & 97.2 \
\text { Rhesus Monkey } & 96.9 \
\text { Rabbit } & 93.7
\end{array}$$

-What probably explains the inclusion of rabbits in this research?

Accepted Answer

A) Their short generation time provides a ready source of DNA. 
B) They possess all of the shared derived characters as do the other species listed. 
C) They are the closest known relatives of rhesus monkeys. 
D) They are the outgroup. 
E) They are the most recent common ancestor of the primates. 
A) Their short generation time provides a ready source of DNA. 
B) They possess all of the shared derived characters as do the other species listed. 
C) They are the closest known relatives of rhesus monkeys. 
D) They are the outgroup. 
E) They are the most recent common ancestor of the primates.

Question 5

The following questions refer to this phylogenetic tree, depicting the origins of life and of the three domains. Horizontal lines indicate instances of gene or genome transfer.
  
-Which process is observed in prokaryotes and is responsible for the vertical components of the various bacterial and archaean lineages?

Accepted Answer

A) mitosis 
B) meiosis 
C) sexual reproduction 
D) binary fission 
A) mitosis 
B) meiosis 
C) sexual reproduction 
D) binary fission

Question 6

The following questions refer to the hypothetical patterns of taxonomic hierarchy shown in Figure 26.2.

-When using a cladistic approach to systematics, which of the following is considered most important for classification?

Accepted Answer

A) shared primitive characters 
B) analogous primitive characters 
C) shared derived characters 
D) the number of homoplasies 
E) overall phenotypic similarity 
A) shared primitive characters 
B) analogous primitive characters 
C) shared derived characters 
D) the number of homoplasies 
E) overall phenotypic similarity

Question 7

The various taxonomic levels (viz, genera, classes, etc.)of the hierarchical classification system differ from each other on the basis of

Accepted Answer

A) how widely the organisms assigned to each are distributed throughout the environment. 
B) the body sizes of the organisms assigned to each. 
C) their inclusiveness. 
D) the relative genome sizes of the organisms assigned to each. 
E) morphological characters that are applicable to all organisms. 
A) how widely the organisms assigned to each are distributed throughout the environment. 
B) the body sizes of the organisms assigned to each. 
C) their inclusiveness. 
D) the relative genome sizes of the organisms assigned to each. 
E) morphological characters that are applicable to all organisms.

Question 8

The following questions refer to the table below, which compares the % sequence homology of four different parts (2 introns and 2 exons) of a gene that is found in five different eukaryotic species. Each part is numbered to indicate its distance from the promoter (e.g., Intron I is that closest to the promoter). The data reported for Species A were obtained by comparing DNA from one member of species A to another member of Species A.
 $\quad $$\quad $$\quad $$\quad $$\quad $$\quad $$\quad $$\text { \%/ Sequence Homology  } $
$\begin{array} { l l l l l } 
\text { Species } & \text { Intron I } & \text { Exon I } & \text { Intron VI } & \text { Exon V } \
\text { A } & 100 \% & 100 \% & 100 \% & 100 \% \
\text { B } & 98 \% & 99 \% & 82 \% & 96 \% \
\text { C } & 98 \% & 99 \% & 89 \% & 96 \% \
\mathrm { D } & 99 \% & 99 \% & 92 \% & 97 \% \
\mathrm { E } & 98 \% & 99 \% & 80 \% & 94 \%
\end{array}$
-Members of which kingdom have cell walls and are all heterotrophic?

Accepted Answer

A) Plantae 
B) Fungi 
C) Animalia 
D) Protista 
E) Monera 
A) Plantae 
B) Fungi 
C) Animalia 
D) Protista 
E) Monera

Question 9

Some molecular data place the giant panda in the bear family (Ursidae)but place the lesser panda in the raccoon family (Procyonidae). Consequently, the morphological similarities of these two species are probably due to

Accepted Answer

A) inheritance of acquired characteristics. 
B) sexual selection. 
C) inheritance of shared derived characters. 
D) possession of analogous structures. 
E) possession of shared primitive characters. 
A) inheritance of acquired characteristics. 
B) sexual selection. 
C) inheritance of shared derived characters. 
D) possession of analogous structures. 
E) possession of shared primitive characters.

Question 10

The following questions refer to the information below.
A researcher compared the nucleotide sequences of a homologous gene from five different species of mammals with the homologous human gene. The sequence homology between each species' version of the gene and the human gene is presented as a percentage of similarity.
 $$\begin{array} { l c } 
\text { Species } & \text { Percentage } \
\hline \text { Chimpanzee } & 99.7 \
\text { Orangutan } & 98.6 \
\text { Baboon } & 97.2 \
\text { Rhesus Monkey } & 96.9 \
\text { Rabbit } & 93.7
\end{array}$$

-When sufficient heat is applied, double-stranded DNA denatures into two single-stranded molecules as the heat breaks all of the hydrogen bonds. In an experiment, molecules of single-stranded DNA from species X are separately hybridized with putatively homologous single-stranded DNA molecules from five species (A-E). The hybridized DNAs are then heated, and the temperature at which complete denaturation occurs is recorded. Based on the data below, which species is probably most closely related to species X?
$\begin{array}{cc}
&\text { Temperature at Which } \
\text { Species } & \begin{array}{c}
\text { Hybridized DNA Denatures }
\end{array} \
\hline \text { A } & 30^{\circ} \mathrm{C} \
\text { B } & 85^{\circ} \mathrm{C} \
\text { C } & 74^{\circ} \mathrm{C} \
\text { D } & 60^{\circ} \mathrm{C} \
\text { E } & 61^{\circ} \mathrm{C}
\end{array}$

Accepted Answer

The answer of The following questions refer to the information...

Exam 26: Phylogeny and the Tree of Life

The most important feature that permits a gene to act as a molecular clock is

The following questions refer to the hypothetical patterns of taxonomic hierarchy shown in Figure 26.2. -If this figure is an accurate depiction of relatedness, then which taxon is unacceptable, based on cladistics?

The following questions refer to the hypothetical patterns of taxonomic hierarchy shown in Figure 26.2. -When using a cladistic approach to systematics, which of the following is considered most important for classification?

The various taxonomic levels (viz, genera, classes, etc.)of the hierarchical classification system differ from each other on the basis of

Some molecular data place the giant panda in the bear family (Ursidae)but place the lesser panda in the raccoon family (Procyonidae). Consequently, the morphological similarities of these two species are probably due to

Introduction: Themes in the Study of Life

The Chemical Context of Life

Water and the Fitness of the Environment

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration: Harvesting Chemical Energy

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Control of Gene Expression

Viruses

Biotechnology

Genomes and Their Evolution

Descent With Modification: a Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity Ii: the Evolution of Seed Plants

Fungi

An Introduction to Animal Diversity

Invertebrates

Vertebrates

Plant Structure, Growth, and Development

Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems

Conservation Biology and Restoration Ecology

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