Question 1

Because DNA:DNA hybridization reveals subtle differences in genes, it is useful for differentiating
A) very similar organisms.
B) organisms from different families.
C) organisms from different domains.
D) organisms from different orders.

Accepted Answer

DNA:DNA hybridization is useful for differentiating very similar organisms because it can reveal subtle differences in genes that may not be detectable through other means. It is less effective for differentiating organisms from different families, domains, or orders because the genetic differences between these groups are typically larger and more apparent.

Question 2

Two eukaryotic organelles that are hypothesized to be the result of endosymbiotic uptake are the________ and the________ .

Accepted Answer

The answer of Two eukaryotic organelles that are hypothesized to...

Question 3

Which statement most closely expresses our present understanding?
A) The chloroplast and the cyanobacteria are not closely (or specifically) related.
B) The chloroplast arose from within the cyanobacterial phylum.
C) The chloroplast is a descendent of the cyanobacteria.
D) The cyanobacteria are descendents of the chloroplast.

Accepted Answer

The most widely accepted theory is that the chloroplast arose from endosymbiosis, where a eukaryotic cell engulfed a cyanobacterium and the two evolved into a single organism. This theory is supported by various pieces of evidence, such as the presence of a double membrane around the chloroplast, the similarity in the photosynthetic machinery of chloroplasts and cyanobacteria, and the fact that both contain their own circular DNA. However, it is important to note that the chloroplast and contemporary cyanobacteria are not the same and have likely diverged significantly since their initial symbiotic relationship.

Question 4

A sequence variant of a gene is called a(n)
A) allele.
B) nucleotide polymorphism.
C) ribotype.
D) mutation.

Accepted Answer

A sequence variant of a gene is typically referred to as an allele.

Question 5

Which molecular technique requires the complementary strand of a nucleotide sequence of interest as a probe to identify its presence?
A) FISH
B) AFLP
C) MLST
D) FAME

Accepted Answer

FISH (Fluorescence in situ hybridization) requires the use of a complementary nucleotide probe that binds to the target sequence being analyzed. By using fluorescently labeled probes, the location and abundance of the target sequence can be visualized using a fluorescence microscope. AFLP (Amplified Fragment Length Polymorphism), MLST (Multi-locus sequence typing), and FAME (Fatty Acid Methyl Ester) are not techniques that involve the use of a nucleotide probe.

Question 6

The most widely used molecule in sequence- based evolutionary analyses are________ genes.
A) SSU rRNA
B) ATPase
C) 18S rRNA
D) electron transport

Accepted Answer

SSU rRNA (Small Subunit Ribosomal RNA) genes are the most widely used in sequence-based evolutionary analyses because they are highly conserved across different species, allowing for comparisons and evolutionary studies.

Question 7

Fluorescent phylogenetic probes are used extensively in
A) microbial ecology.
B) rapid identification of specific species.
C) clinical diagnostics.
D) all of the above.

Accepted Answer

Fluorescent phylogenetic probes are versatile tools that can be used in microbial ecology to track specific organisms, in rapid identification of species for diagnostic purposes, and in clinical diagnostics to identify pathogens. Therefore, all of the choices are correct.

Question 8

The substance that has been shown to catalyze various chemical reactions and that helped form the structured mounds surrounding hydrothermal springs on the ocean floor on early Earth is known as _________.

Accepted Answer

The answer of The substance that has been shown to...

Question 9

Traits currently considered most important for grouping strains together as a species include________ and ________.

Accepted Answer

The answer of Traits currently considered most important for grouping...

Question 10

The study of the diversity of organisms and their relationships is known a________s , which links together _ ________and ________, in which organisms are characterized, named, and placed into groups according to their natural relationships.

Accepted Answer

The answer of The study of the diversity of organisms...

Question 11

A web- based algorithm used for aligning and identifying homologous sequences is called________.

Accepted Answer

The answer of A web- based algorithm used for aligning...

Question 12

The earliest stromatolites were probably
A) anoxygenic phototrophs.
B) oxygenic phototrophs.
C) anoxygenic lithotrophs.
D) oxygenic lithotrophs.

Accepted Answer

The earliest stromatolites, which are layered structures formed by the activity of microorganisms, were likely formed by anoxygenic phototrophs. These organisms used light for energy but did not produce oxygen as a byproduct, as they existed before the Great Oxygenation Event.

Question 13

In the binomial system of nomenclature, each organism is given a(n)________ name and a(n) ________epithet.

Accepted Answer

The answer of In the binomial system of nomenclature, each...

Question 14

A highly specific and rapid molecular technique called________ can serve as a clinical diagnostic tool to identify DNA fingerprints of infectious agents rather than performing DNA sequencing.

Accepted Answer

The answer of A highly specific and rapid molecular technique...

Question 15

The early energy reactions yielded hydrogen, which is a powerful ________and could have been used to form a(n)________ .

Accepted Answer

The answer of The early energy reactions yielded hydrogen, which...

Question 16

The evolutionary history of a group of organisms is called its________ and it is inferred indirectly from________ .

Accepted Answer

The answer of The evolutionary history of a group of...

Question 17

The rise in atmospheric oxygen, caused by the photosynthetic production of oxygen by the________, allowed for the origin of eukaryotes.

Accepted Answer

The answer of The rise in atmospheric oxygen, caused by...

Question 18

Chemical reactions involving ________have been proposed as energy- yielding reactions for primitive organisms.
A) iron, sulfur, and oxygen
B) iron, oxygen, and hydrogen
C) sulfur, oxygen, and hydrogen
D) iron, sulfur, and hydrogen

Accepted Answer

Iron, sulfur, and hydrogen have been proposed as energy-yielding reactions for primitive organisms. This is known as the iron-sulfur world hypothesis, which suggests that the first living organisms on Earth may have used metal-sulfur compounds as their source of energy before the emergence of photosynthesis. The reaction involves the oxidation of reduced iron and reduced sulfur compounds by molecular hydrogen to produce energy and the oxidized forms of the metals and sulfur.

Question 19

The eukaryotic functional equivalent of the prokaryotic 16S rRNA is the
A) 18S rRNA.
B) 5S rRNA.
C) 16S rRNA.
D) 23S rRNA.

Accepted Answer

The eukaryotic functional equivalent of the prokaryotic 16S rRNA is the 18S rRNA. This is because the 18S rRNA corresponds to the small ribosomal subunit in eukaryotes, which is functionally equivalent to the prokaryotic 16S rRNA in the small ribosomal subunit. The 18S rRNA is involved in the recognition of the mRNA start codon during translation.

Question 20

Although the microsporidia and the diplomonads are eukaryotic, they lack
A) a true nucleus.
B) identifiable ribosomes.
C) mitochondria.
D) all of the above.

Accepted Answer

Both the microsporidia and the diplomonads lack mitochondria, although they do have a nucleus and ribosomes.

Quiz 16: Microbial Evolution and Systematics

Because DNA:DNA hybridization reveals subtle differences in genes, it is useful for differentiating

Two eukaryotic organelles that are hypothesized to be the result of endosymbiotic uptake are the and the .

Which statement most closely expresses our present understanding?

A sequence variant of a gene is called a(n)

Which molecular technique requires the complementary strand of a nucleotide sequence of interest as a probe to identify its presence?

The most widely used molecule in sequence- based evolutionary analyses are________ genes.

Fluorescent phylogenetic probes are used extensively in

The substance that has been shown to catalyze various chemical reactions and that helped form the structured mounds surrounding hydrothermal springs on the ocean floor on early Earth is known as _________.

Traits currently considered most important for grouping strains together as a species include and .

The study of the diversity of organisms and their relationships is known a________s , which links together _ and , in which organisms are characterized, named, and placed into groups according to their natural relationships.

A web- based algorithm used for aligning and identifying homologous sequences is called________.

The earliest stromatolites were probably

In the binomial system of nomenclature, each organism is given a(n) name and a(n) epithet.

A highly specific and rapid molecular technique called________ can serve as a clinical diagnostic tool to identify DNA fingerprints of infectious agents rather than performing DNA sequencing.

The early energy reactions yielded hydrogen, which is a powerful and could have been used to form a(n) .

The evolutionary history of a group of organisms is called its and it is inferred indirectly from .

The rise in atmospheric oxygen, caused by the photosynthetic production of oxygen by the________, allowed for the origin of eukaryotes.

Chemical reactions involving ________have been proposed as energy- yielding reactions for primitive organisms.

The eukaryotic functional equivalent of the prokaryotic 16S rRNA is the

Although the microsporidia and the diplomonads are eukaryotic, they lack