Question 1

The assignment of names to taxonomic groups is referred to as ______.

Accepted Answer

The assignment of names to taxonomic groups is known as nomenclature. Taxonomy refers to the overall study of classifying organisms, systematics is a broader term that includes not only classification but also the study of evolutionary relationships, and identification refers to the process of determining the identity of an organism based on its characteristics.

Question 2

Which of the following is an example of the use of the binomial system devised by Linnaeus?

Accepted Answer

Escherichia coli is an example of the use of the binomial system devised by Linnaeus as it is given a unique two-part Latin name consisting of the genus (Escherichia) and the species (coli). The other options are not examples of binomial nomenclature as they are either at a higher taxonomic level (Enterobacteriaceae, Enterobacteriales) or a serovar of E. coli (O157:H7).

Question 3

Which of the following is not true about the G + C content percentages in DNA of organisms?

Accepted Answer

Organisms with similar G + C content percentages do not necessarily have similar base sequences. The G + C content gives an indication of the overall composition of the genome but does not directly translate to specific sequences of bases being similar. Two organisms can have similar G + C percentages but vastly different genetic sequences and functions.

Question 4

The determination of the taxon to which an organism belongs is called ______.

Accepted Answer

The determination of the taxon to which an organism belongs is referred to as identification. Taxonomy, classification, and systematics are all involved in the organization and categorization of living things, but they do not involve the specific determination of a particular organism's taxonomic group.

Question 5

The general order of classification below the domain or kingdom level is

Accepted Answer

The correct order of classification below the domain or kingdom level is phyla, class, order, family, genus, species.

Question 6

A classification system based on evolutionary relationships is called a __________ system.

Accepted Answer

A phylogenetic system is based on the evolutionary relationships between organisms, while a phenetic system is based on observable characteristics and a systematic system encompasses both. A determinative system is one that focuses on identifying organisms based on specific characteristics, rather than their evolutionary relationships. Therefore, A)phylogenetic is the best choice for a classification system based on evolutionary relationships.

Question 7

The science dealing with classification is called ______.

Accepted Answer

Taxonomy is the branch of science that deals with the classification of living organisms. It involves defining and naming groups of biological organisms on the basis of shared characteristics or traits. Nomenclature refers to the assignment of names to organisms, while systematics is a broader field that encompasses both taxonomy and the study of evolutionary relationships among organisms. Identification is the process of recognizing and naming a particular organism or species.

Question 8

Which of the following is useful in biological systematics?

Accepted Answer

All of the choices are correct as they are useful in biological systematics. Physiology helps in studying the functions of organisms and their systems, epidemiology helps in understanding the spread of diseases and how they affect populations, ecology helps in analyzing the relationships between organisms and their environment. All of these are important aspects to consider when classifying and categorizing organisms in biological systematics.

Question 9

A population descending from a single organism or pure culture isolate is called a ______.

Accepted Answer

A population descending from a single organism or pure culture isolate is called a strain. A genus refers to a group of closely related organisms, a species refers to a group of organisms that share common characteristics and can interbreed, and a subspecies refers to a geographically distinct population within a species.

Question 10

Stable annealing due to hydrogen bonding between DNAs of similar nucleotide sequence from different organisms is referred to as _______.

Accepted Answer

Stable annealing between DNAs of similar nucleotide sequence from different organisms is referred to as hybridization. Hydrolysis refers to a chemical reaction involving the breaking of a bond using water. Restriction refers to the cutting of DNA at specific sites by restriction enzymes. Ligation refers to the joining of two DNA fragments by a ligase enzyme.

Question 11

The arrangement of organisms into groups is best described as ______.

Accepted Answer

The term "classification" specifically refers to the arrangement of organisms into groups based on common characteristics. Taxonomy and systematics are broader terms that may also encompass the naming and study of these groups, respectively. Identification refers to the process of determining the name or classification of an unknown organism based on its characteristics.

Question 12

The analysis of genetic relatedness by observing the DNA fragmentation patterns resulting from restriction endonuclease cleavage is referred to as ______.

Accepted Answer

Genetic fingerprinting is the commonly used term to describe the analysis of genetic relatedness by observing DNA fragmentation patterns resulting from restriction endonuclease cleavage.

Question 13

A classification system based on mutual similarity that involves comparing as many characteristics as possible is called a __________ system.

Accepted Answer

A phenetic system (also known as numerical taxonomy) is based on overall similarities between organisms, regardless of their evolutionary relationships or phylogenetic history. This method involves comparing as many characteristics as possible in order to create a hierarchical classification system based on overall similarity. A phylogenetic system, on the other hand, is based on evolutionary relationships and shared ancestry, while a phyletic system focuses on the ancestral lineage of different groups. A determinative systematic system involves using specific characteristics or traits to identify and classify organisms, rather than overall similarity.

Question 14

Mole percent (G+C)of DNA is useful for determining relatedness at the __________ level.

Accepted Answer

Mole percent (G+C) of DNA is considered a useful tool for determining relatedness between microorganisms at the genus level. It is not as useful for higher taxonomic levels such as kingdom or class.

Question 15

A general term used to describe groups based on mutual similarity or evolutionary relatedness is ______.

Accepted Answer

Taxa is a general term used to describe groups based on mutual similarity or evolutionary relatedness. Class and system are more specific terms used to describe taxonomic ranks within a classification system, and group is a more generic term that could refer to any type of collection or assemblage.

Question 16

The temperature at which half of the strands of a double-stranded DNA molecule have separated from each other is called the __________ temperature.

Accepted Answer

The process of separating the two strands of a DNA molecule is called denaturation or melting. The temperature at which half of the strands have separated from each other is called the melting temperature or Tm. Therefore, the best choice is B, melting temperature.

Question 17

The binomial system of nomenclature assigns each organism a scientific name consisting of

Accepted Answer

The binomial system of nomenclature assigns each organism a scientific name consisting of genus and species. This system was devised by the Swedish biologist Carl Linnaeus in the 18th century and is still used today to classify and name organisms. The genus always comes first, followed by the species. For example, Homo sapiens is the scientific name for humans, with Homo being the genus and sapiens being the species.

Question 18

An unrooted tree containing four unrelated species can become rooted by adding

Accepted Answer

A distantly related outgroup can be used to root an unrooted tree by providing a point of reference for the evolutionary relationships among the species.

Question 19

The organisms in which of the following are more closely related?

Accepted Answer

Family is a more specific taxonomic category than order, class, or phylum, indicating that organisms within the same family are more closely related to each other.

Question 20

Conserved indels are

Accepted Answer

Conserved indels are insertions or deletions in protein sequences that are present in all (or most) members of a particular group of organisms and are absent in individuals from other lineages, making them useful as phylogenetic markers. Conserved indels are not transposable elements, mRNA sequences, or alterations due to small deletions in protein-coding genes.

Quiz 19: Microbial Taxonomy and the Evolution of Diversity