Deck 7: Archael and Eukaryotic Molecular Biology

Question 1

RdRP is an enzyme that copies siRNA in

A) plants.
B) Archaea.
C) Bacteria.
D) humans.

Answer 1

A

Question 2

Archaeal introns are excised by

A) a specific endoribonuclease.
B) a ribozyme.
C) the spliceosome.
D) restriction endonucleases.

Answer 2

A

Question 3

Histones are positively charged _ that bind to and neutralize the charge of , which is caused by the presence of phosphate groups.

A) DNA / DNA
B) DNA / RNA
C) proteins / DNA
D) RNA / RNA

Answer 3

C

Question 4

The processes of transcription and translation are coupled processes in

A) eukaryotic cells.
B) prokaryotic cells.
C) both eukaryotic and prokaryotic cells.
D) neither eukaryotic nor prokaryotic cells.

Question 5

Intron removal and exon joining are accomplished by the

A) cytoskeleton.
B) microtubules.
C) spliceosome.
D) telomerase enzyme.

Question 6

The assemblage of proteins that serve as a binding site for spindle fibers and bind to chromosomal DNA at the centromere region are called

A) telomeres.
B) mitotic spindle complexes.
C) chromatids.
D) kinetochore complexes.

Question 7

Which enzyme aids in replication of DNA at the guanine- rich 3' end of a strand of DNA?

A) DNA polymerase
B) hydrolase
C) RNAse
D) telomerase

Question 8

Protein- encoding genes are often split into two or more coding regions called and noncoding regions known as .

A) introns / exteins
B) exons / introns
C) exons / inteins
D) introns / exons

Question 9

During eukaryotic RNA processing methylated guanine nucleotides are added at the terminus in a process called .

A) 3' / polytailing
B) 5' / polytailing
C) 5' / capping
D) 3' / capping

Question 10

Compared with the amount of DNA in a single yeast chromosome, the amount of DNA in a single prokaryotic chromosome is

A) less.
B) not discernible without comparing specific species.
C) about the same.
D) greater.

Question 11

Healthy eukaryotic cells contain all of the following EXCEPT

A) proteins.
B) ssRNA.
C) dsDNA.
D) dsRNA.

Question 12

The antibiotic rifampicin inhibits RNA polymerase from which domain?

A) Archaea
B) Bacteria
C) Eukarya
D) Rifampicin does not inhibit RNA polymerase from any of these domains.

Question 13

The first amino acid in an archaeal protein is

A) N- formylserine.
B) methionine.
C) pyrrolysine.
D) N- formylmethionine.

Question 14

Both Bacteria and Archaea share the trait of

A) transcribing several genes onto the same polycistronic mRNA.
B) lacking a nucleus.
C) the genome being typically a single circular chromosome.
D) all of the above.

Question 15

An important sequence in the initiation of transcription in Archaea is the

A) Pribnow box.
B) start codon.
C) TATA box.
D) polysome site.

Question 16

Archaeal and bacterial mRNA often serve as templates for several different proteins to be co- transcribed, however eukaryotic mRNA that makes only a single protein are

A) monocistronic.
B) unique during meiosis.
C) called inteins.
D) a result of too much splicing.

Question 17

The Archaea were originally regarded as members of the Bacteria because

A) neither has membrane- bound organelles.
B) neither has a nucleus.
C) both typically contain a single circular chromosome.
D) all of the above are correct.

Question 18

Which statement is TRUE?

A) Introns are the exception rather than the rule in eukaryotic encoding genes, and the lower eukaryotes have fewer and smaller introns than the higher eukaryotes.
B) Essentially all eukaryotic encoding genes have introns, and the higher eukaryotes have more introns than the lower eukaryotes.
C) Essentially all eukaryotic encoding genes have introns, and the lower eukaryotes have fewer introns than the higher eukaryotes.
D) Introns are the exception rather than the rule in eukaryotic encoding genes, and the higher eukaryotes have fewer and smaller introns than the lower eukaryotes.

Question 19

Which of the following statements is NOT true regarding transcription?

A) The TATA box is unique to Archaea, Eukarya, and the Pribnow promoter region in Bacteria.
B) Archaea use only one type of RNA polymerase, which is similar to the eukaryotic RNA polymerase II.
C) All promoters in Archaea and Eukarya require transcription factors for RNA polymerase recruitment.
D) Relatively little is understood about how an archaeon terminates a transcript except that Rho- like proteins are involved.

Question 20

An mRNA transcript may be polycistronic in

A) eukaryotic cells.
B) prokaryotic cells.
C) both eukaryotic and prokaryotic cells.
D) neither eukaryotic nor prokaryotic cells.

Question 21

RNA processing in eukaryotic cells removes .

Question 22

Regulation of transcription in Archaea is similar to that of , while the transcription apparatus of Archaea is similar to that of .

Question 23

The complex of DNA plus histones is known as _ and when highly condensed is called .

Question 24

The is that contains both introns and exons.

Question 25

Bacteria use DNA polymerases of family C as their _ , whereas DNA polymerases of families A and B are used mostly in _ .

Question 26

are introns that fold up to generate three- dimensional structures with _ activity.

Question 27

Eukaryotic chromosomes contain both and _ that Archaea and Bacteria
lack.

Question 28

Which statement is TRUE?

A) Proteins are not associated with either prokaryotic or eukaryotic chromosomes.
B) Proteins are equally associated with prokaryotic and eukaryotic chromosomes.
C) Large amounts of protein are bound to eukaryotic DNA in a very regular fashion, whereas proteins are absent from prokaryotic DNA.
D) Large amounts of protein are bound to prokaryotic DNA in a very regular fashion, whereas proteins are absent from eukaryotic DNA.

Question 29

The stabilizes mRNA and indicates to the translation machinery that the RNA is mRNA rather than some other form of RNA.

Question 30

is a specific type of regulatory RNA that minimizes sequence repeats in of higher animals.

Question 31

Monocistronic mRNA occurs in domain , while polycistronic mRNA occurs in domain .

Question 32

The presence of dsRNA usually indicates the presence of _ within a cell; this molecule is eliminated from eukaryotes through a mechanism known as _.

Question 33

Chromosomal DNA at regular intervals contains condensed DNA complexes, in which DNA is wrapped around a histone tetramer in Archaea and a histone octamer in Eukarya, and are called

A) histonosomes.
B) chromatin.
C) nucleosomes.
D) supercoiled DNA.

Question 34

During mRNA processing, nucleotide sequences are removed as a(n) .

Question 35

The guanine- rich sequence that can base pair with the 3' end of a complementary RNA present in telomerase is found on the strand of DNA.

Question 36

snRNPs are involved in the process of .

Question 37

Telomeres are

A) regions that provide an attachment site for the spindle fibers that pull paired chromosomes apart during mitosis.
B) the complex assemblage of proteins that links the DNA of the centromere region to the spindle fibers.
C) repetitive DNA sequences that are used to replicate the ends of eukaryotic chromosomes.
D) specific proteins that bind to the ends of linear chromosomes and provide DNA polymerase with a free hydroxyl group onto which the first nucleotide can be added.

Question 38

is the process that occurs in each haploid Saccharomyces cerevisiae cell before cell division.

Question 39

The 5.8S rRNA is a ribosomal protein found in but not in .

Question 40

Regulation of transcription in Archaea shares major similarities with that of Bacteria, perhaps because of and _.

Question 41

The RISC complex recognizes and destroys ssRNA (e.g., mRNA) that corresponds in sequence to siRNA.

Question 42

Both intron and exon regions are transcribed into the primary transcript.

Question 43

Technically, telomerase is an unusual type of reverse transcriptase.

Question 44

is the enzyme that introduces positive supercoils into DNA that is found in the
domain(s).

Question 45

Regulation of transcription in Archaea is more similar to that which occurs in eukaryotes than in bacteria.

Question 46

Comparative rRNA gene sequencing has revealed a closer genetic relationship between Archaea
and Bacteria than between Archaea and Eukarya.

Question 47

All organisms possess multiple DNA polymerases in part due to their functional diversity that all cells require.

Question 48

Transcription and translation are spatially separate processes in , because the
are located in the nucleus and the are in the cytoplasm.

Question 49

Cells that have two of each chromosome are , whereas cells that have only one copy of each chromosome are .

Question 50

With rare exceptions, reverse gyrase is present only in .

Question 51

RNA polymerase I transcribes genes for _ , RNA polymerase II transcribes genes for all of the , and RNA polymerase III transcribes genes for .

Question 52

Positive supercoiling protects archaeal DNA against ultraviolet (UV) radiation.

Question 53

The guanosine cap that is formed during mRNA processing is needed for translation because _ .

Question 54

Archaea contain RNA polymerase(s), which have roughly three times more subunits than those found in .

Question 55

From the standpoint of molecular biology, two similarities between the Archaea and the
Eukarya are and _ .

Question 56

The conserved sequence of the in eukaryotes somewhat resembles the Pribnow box in the promoters of Bacteria.

Question 57

Archaeal transcript splicing first uses a(n) to excise introns and lastly joins the exons together with _ .

Question 58

All DNA polymerases must add each nucleotide to a(n) , which is often denoted as the end.

Question 59

Histones are universally present in prokaryotic cells.

Question 60

Several genes encoding and of Archaea possess introns that must be removed following transcription to generate the mature molecules.

Question 61

Ribosomes contain rRNA plus proteins. All of the proteins contained in the ribosome are common to Archaea, Bacteria, and Eukarya.

Question 62

RNAi is triggered by dsDNA of greater than 20 bp in length.

Question 63

Reverse gyrase introduces negative supercoils into DNA.

Question 64

Introns and exons are found in Eukarya, but they are extremely rare in both Bacteria and Archaea.

Question 65

Prokaryotes have almost no introns. What is the significance of this?

Question 66

Consider the lifetime of an mRNA transcript within an archaeon, a bacterium, and a eukaryote. In which cell type might these last the longest and why?

Question 67

Compare and contrast RNA interference (RNAi) and restriction endonucleases.

Question 68

Explain why multiple origins of replication are seen in the chromosomes of Archaea and Eukarya.

Question 69

Explain why a mutation in the gene that encodes telomerase would be a lethal mutation.

Question 70

DNA packaging in Archaea resembles both Bacteria and Eukarya. In what way(s) is DNA packaging analogous to
Bacteria and in what way(s) is it analogous to Eukarya?

Question 71

Explain why it is unsurprising that mitochondria and chloroplasts contain RNA polymerase, which is bacterial in origin.

Question 72

Proteins resembling the Rho proteins in Bacteria have been detected in Archaea.

Question 73

The translational machinery of Archaea is more similar to Bacteria than to Eukarya.

Question 74

Diagram the process of meiosis.

Question 75

Suppose you are comparing the protein- encoding DNA from two species. In one species, 92% of the DNA encodes proteins, while in the second species, only 7.5% of the DNA encodes proteins. To what domain does each species belong? Explain your answer fully.

Question 76

Compare and contrast enzymes and ribozymes of self- splicing introns.

Question 77

Explain how eukaryotic chromosomes are formed.

Question 78

Explain the necessity for a protein primer during replication of linear DNA.

Question 79

In eukaryotes, DNA is wound around clusters of histones, forming structures known as nucleosomes.

Question 80

Compare and contrast the processes of meiosis and mitosis.