Question 1

Fossil evidence indicates that prokaryotic cells first existed on the Earth at least
A)350 years ago.
B)3500 years ago.
C)35000 years ago.
D)3.5 billion years ago.
E)3.5 × 10¹² years ago.

Accepted Answer

Fossil evidence suggests that the oldest prokaryotic cells, similar to modern-day bacteria, existed on Earth approximately 3.5 billion years ago.

Question 2

Figure 10.1
 
-In Figure 10.1,the closest ancestor for both species "a." and species "b." would be which of the following?
A)1
B)2
C)3
D)4
E)5

Accepted Answer

E

Question 3

Which one of the following provides taxonomic information that includes the information obtained in each of the other options listed?
A)nucleic acid hybridization
B)nucleic acid-base composition
C)amino acid sequencing
D)biochemical tests
E)cladogram

Accepted Answer

A cladogram is a diagram that shows the evolutionary relationships among a group of organisms, incorporating various types of data including nucleic acid hybridization, nucleic acid-base composition, amino acid sequencing, and results from biochemical tests. It provides a comprehensive overview of taxonomic relationships.

Question 4

If two organisms have similar rRNA sequences,you can conclude that they
A)live in the same place.
B)evolved from a common ancestor.
C)will have different G-C ratios.
D)will both ferment lactose.
E)mated with each other.

Accepted Answer

Two organisms with similar rRNA sequences are likely to have evolved from a common ancestor. rRNA is highly conserved and evolves at a relatively slow rate, making it a useful tool for studying evolutionary relationships between organisms. By comparing rRNA sequences, scientists can construct phylogenetic trees that show the evolutionary history and relatedness of different species.

Question 5

Which of the following statements about archaea is FALSE?
A)They are prokaryotes.
B)They lack peptidoglycan in their cell walls.
C)Some are thermoacidophiles;others are extreme halophiles.
D)They evolved before bacteria.
E)Some produce methane from carbon dioxide and hydrogen.

Accepted Answer

Archaea and bacteria are both prokaryotes, and archaea have been found to lack peptidoglycan in their cell walls. Some archaea are thermoacidophiles (thriving in hot, acidic environments) or extreme halophiles (living in very salty conditions). However, it is not true that archaea evolved before bacteria; both groups emerged at roughly the same time in Earth's history. Lastly, some archaea are known to produce methane from carbon dioxide and hydrogen, making them important players in the carbon cycle.

Question 6

A genus can best be defined as
A)a taxon composed of families.
B)a taxon composed of one or more species and a classification level lying below family.
C)a taxon belonging to a species.
D)a taxon comprised of classes.
E)the most specific taxon.

Accepted Answer

A genus is a taxonomic rank that lies below family and is composed of one or more species. It is more specific than family but less specific than species.

Question 7

Which of the following statements about the members of the Kingdom Animalia is FALSE?
A)They are multicellular.
B)They are composed of eukaryotic cells.
C)They undergo photosynthesis.
D)They ingest nutrients through a mouth.
E)They are heterotrophs.

Accepted Answer

The statement that members of the Kingdom Animalia undergo photosynthesis is false. Animals do not have the ability to produce their own food by photosynthesis and instead must consume other organisms to obtain nutrients.

Question 8

Figure 10.1
 
-In Figure 10.1,species "c." is most closely related to which of the following?
A)a
B)b
C)c
D)d
E)e

Accepted Answer

The answer of Figure 10.1
 
-In Figure 10.1,species "c." is...

Question 9

What is the outstanding characteristic of the Kingdom Fungi?
A)All members are photosynthetic.
B)Members absorb dissolved organic matter.
C)Members absorb dissolved inorganic matter.
D)All members are microscopic.
E)All members are macroscopic.

Accepted Answer

The outstanding characteristic of the Kingdom Fungi is that all members absorb dissolved organic matter, making them heterotrophs. They are unable to produce their own food through photosynthesis like the members of Kingdom Plantae (A). While some members may also absorb dissolved inorganic matter (C), this is not their primary mode of nutrition. Some members are microscopic (D), while others are macroscopic (E), but this is not the defining characteristic of the group.

Question 10

A bacterial species differs from a species of eukaryotic organisms in that a bacterial species
A)does not breed with other species.
B)has a limited geographical distribution.
C)can be distinguished from other bacterial species.
D)is a population of cells with similar characteristics.
E)breeds with its own species.

Accepted Answer

Bacterial species are defined as a population of cells that have similar characteristics, distinguishing them from the concept of species in eukaryotic organisms which often includes reproductive isolation and other criteria.

Question 11

In the scientific name Enterobacter aerogenes,Enterobacter is the
A)specific epithet.
B)genus.
C)family.
D)order.
E)kingdom.

Accepted Answer

Enterobacter is the genus in the scientific name Enterobacter aerogenes.

Question 12

Which one of the following statements is a reason for NOT classifying viruses in one of the threedomains of life (Bacteria,Archaea,Eukarya)rather than in a fourth separate domain?
A)Some viruses can incorporate their genome into a host's genome.
B)Viruses direct anabolic pathways of host cells.
C)Viruses are obligate parasites.
D)Viruses are not composed of cells.

Accepted Answer

Viruses are not composed of cells, which is one of the defining characteristics of the three domains of life. Therefore, they cannot be classified within these domains and require a separate domain.

Question 13

A biochemical test,in the microbiology world,is used to determine
A)staining characteristics.
B)amino acid sequences of enzymes.
C)nucleic acid-base composition of DNA sequences.
D)capability of a microbe to perform a specific enzymatic activity.
E)All of the answers are correct.

Accepted Answer

Biochemical tests are used to determine the capability of a microbe to perform a specific enzymatic activity. This can help in identifying the microbe and its properties. Amino acid sequences and nucleic acid-base composition are determined through other techniques such as sequencing, while staining characteristics can provide some information about the microbe's structure but not its function. Therefore, D is the best choice.

Question 14

Which of the following is NOT based on nucleic-acid hybridization?
A)DNA chip
B)FISH
C)PCR
D)Southern blotting
E)Western blotting

Accepted Answer

Western blotting is a technique used to detect and analyze proteins, whereas the other options are all based on nucleic-acid hybridization. DNA chip, FISH (fluorescence in situ hybridization), PCR (polymerase chain reaction), and Southern blotting all use nucleic-acid hybridization to identify and study DNA or RNA molecules.

Question 15

The phylogenetic classification of bacteria is based on
A)cell morphology.
B)Gram reaction.
C)rRNA sequences.
D)habitat.
E)diseases.

Accepted Answer

The phylogenetic classification of bacteria is primarily based on rRNA sequences because they are highly conserved and have low mutation rates, making them useful for studying evolutionary relationships. This has led to the creation of the three-domain system, which groups organisms into Bacteria, Archaea, and Eukarya based on differences in their rRNA sequences.

Question 16

Which of the following statements about members of the Kingdom Plantae is FALSE?
A)They are multicellular.
B)They are composed of eukaryotic cells.
C)They undergo photosynthesis.
D)They use organic carbon sources.
E)They synthesize organic molecules.

Accepted Answer

Members of the Kingdom Plantae are autotrophs, meaning that they synthesize their own organic molecules through photosynthesis and do not rely on external organic carbon sources. Therefore, statement D is false as it is describing a characteristic of heterotrophs.

Question 17

Which of the following characterizes the Domain Bacteria?
A)prokaryotic cells;ether linkages in phospholipids
B)eukaryotic cells;ester linkages in phospholipids
C)prokaryotic cells;ester linkages in phospholipids
D)complex cellular structures
E)multicellular

Accepted Answer

Bacteria are characterized by having prokaryotic cells, which lack a nucleus, and their cell membranes contain ester linkages in phospholipids, distinguishing them from Archaea, which have ether linkages.

Question 18

________ are a diverse group of eukaryotic organisms that are similar in rRNA sequences,but quite different from each other in motility types and ecology.They have been used previously as a "catch-all" for organisms that couldn't be easily classified into other groups.
A)Protists
B)Fungi
C)Plants
D)Methanogens

Accepted Answer

The description provided fits the characteristics of protists, which are a diverse group of eukaryotic organisms that do not fit into other traditional kingdoms such as animals, fungi, or plants. They share similar rRNA sequences but have different motility types and ecologies.

Question 19

The arrangement of organisms into taxa
A)shows degrees of relatedness between organisms.
B)shows relationships to common ancestors.
C)was designed by Charles Darwin.
D)is arbitrary.
E)is based on evolution.

Accepted Answer

The arrangement of organisms into taxa is based on the degrees of relatedness between organisms. The more closely related two species are, the more similar their characteristics and the more recently they shared a common ancestor. This information is used to group organisms into taxonomic categories based on their evolutionary relationships.

Question 20

Which of the following is the best evidence for a three-domain system?
A)Nucleotide sequences in ribosomal RNA vary between all three domains.
B)There are three distinctly different sets of metabolic reactions.
C)There are three distinctly different Gram reactions.
D)Some bacteria live in extreme environments.
E)There are three distinctly different types of nuclei.

Accepted Answer

Nucleotide sequences in ribosomal RNA vary between all three domains. This is the most widely accepted evidence for the three-domain system, as it shows that the three domains (Bacteria, Archaea, and Eukarya) diverged from a common ancestor and have evolved distinct differences in their genetic material over time. The other options are not as strong evidence for the three-domain system.

Quiz 10: Classification of Microorganisms

Fossil evidence indicates that prokaryotic cells first existed on the Earth at least

Figure 10.1 -In Figure 10.1,the closest ancestor for both species "a." and species "b." would be which of the following?

Which one of the following provides taxonomic information that includes the information obtained in each of the other options listed?

If two organisms have similar rRNA sequences,you can conclude that they

Which of the following statements about archaea is FALSE?

A genus can best be defined as

Which of the following statements about the members of the Kingdom Animalia is FALSE?

Figure 10.1 -In Figure 10.1,species "c." is most closely related to which of the following?

What is the outstanding characteristic of the Kingdom Fungi?

A bacterial species differs from a species of eukaryotic organisms in that a bacterial species

In the scientific name Enterobacter aerogenes,Enterobacter is the

Which one of the following statements is a reason for NOT classifying viruses in one of the threedomains of life (Bacteria,Archaea,Eukarya) rather than in a fourth separate domain?

A biochemical test,in the microbiology world,is used to determine

Which of the following is NOT based on nucleic-acid hybridization?

The phylogenetic classification of bacteria is based on

Which of the following statements about members of the Kingdom Plantae is FALSE?

Which of the following characterizes the Domain Bacteria?

________ are a diverse group of eukaryotic organisms that are similar in rRNA sequences,but quite different from each other in motility types and ecology.They have been used previously as a "catch-all" for organisms that couldn't be easily classified into other groups.

The arrangement of organisms into taxa

Which of the following is the best evidence for a three-domain system?