Question 1

What is the smallest number of nucleotides that must be added or subtracted to change the triplet grouping of the genetic message?
A)one
B)two
C)three
D)four

Accepted Answer

The answer of What is the smallest number of nucleotides...

Question 2

Scientific research companies sell kits that allow researchers to produce proteins in test tubes via a process known as "in vitro translation." Which one of following components is NOT needed in these kits?
A)amino acids
B)transfer RNA
C)DNA
D)ribosomes

Accepted Answer

In vitro translation kits already contain pre-made templates of DNA, so researchers do not need to include their own DNA in the kit. Amino acids, tRNA, and ribosomes are all necessary components for protein synthesis in vitro.

Question 3

The absence of a terminator in transcription will result in ________.
A)the creation of a virus
B)a strand of mRNA that lacks its cap and tail
C)the production of a longer RNA molecule
D)the production of a shorter RNA molecule

Accepted Answer

Without a terminator, RNA polymerase will not stop transcription at the correct point, leading to the production of a longer RNA molecule.

Question 4

Plant viruses ________.
A)often use RNA,rather than DNA,as their genetic material
B)benefit plants,rather than causing disease
C)cause diseases that can be easily cured
D)do not exist,as viruses attack only animals

Accepted Answer

Plant viruses often use RNA as their genetic material rather than DNA.

Question 5

The CORRECT sequence of events occurring during transcription is ________.
A)splicing,capping,tailing
B)initiation,elongation,termination
C)tailing,capping,splicing
D)elongation,initiation,termination

Accepted Answer

The correct sequence of events during transcription is initiation (when the RNA polymerase binds to the promoter sequence), elongation (when the RNA polymerase adds nucleotides to the growing mRNA strand), and termination (when the RNA polymerase reaches the terminator sequence and releases the mRNA transcript). Splicing (removing introns and joining exons) occurs during mRNA processing, while capping and tailing (adding 5' methylguanosine cap and 3' poly-A tail) occur after transcription.

Question 6

The expressed (coding)regions of eukaryotic genes are called ________.
A)caps
B)promoters
C)exons
D)introns

Accepted Answer

Exons are the expressed regions of eukaryotic genes, meaning they are the parts of the gene that are transcribed into mRNA and eventually translated into protein. Promoters are regions that signal the start of transcription, while introns are non-coding regions that are transcribed but then removed by splicing before the mRNA is translated. Caps refer to the modified nucleotides that are added to the ends of mRNA molecules.

Question 7

Mad cow disease is caused by
A)a retrovirus similar to HIV.
B)an enveloped virus.
C)small circular RNA molecules called viroids.
D)infectious proteins called prions.

Accepted Answer

Mad cow disease, also known as bovine spongiform encephalopathy, is caused by infectious proteins called prions. These prions can cause brain damage and eventually lead to death.

Question 8

What is the ultimate source of all diversity?
A)natural selection
B)sexual recombination
C)meiosis
D)mutation

Accepted Answer

Mutation is the ultimate source of all diversity. It is the process by which new genetic variations are generated. Natural selection, sexual recombination, and meiosis play a role in shaping and distributing this diversity, but they are not the ultimate source of it.

Question 9

Peptide bonds form between ________.
A)amino acids
B)an mRNA codon and a tRNA anticodon
C)a tRNA and the amino acid it is carrying
D)an mRNA transcript and the small ribosomal subunit

Accepted Answer

Peptide bonds form between amino acids during the process of protein synthesis.

Question 10

What protects mRNA from attack by cellular enzymes?
A)RNA splicing
B)the removal of exons
C)the lack of RNA-digesting enzymes in the cytoplasm
D)a cap and tail

Accepted Answer

A cap and tail protect mRNA from attack by cellular enzymes. The cap is a modified guanine nucleotide added to the 5' end of mRNA, while the tail is a string of adenine nucleotides added to the 3' end. These modifications prevent enzymes from degrading the mRNA, allowing it to be translated into protein. RNA splicing and the removal of exons are processes that occur within the mRNA molecule itself but do not protect it from enzymatic degradation. There are RNA-digesting enzymes in the cytoplasm, so the lack of such enzymes is not a viable option.

Question 11

Where is translation accomplished?
A)lysosomes
B)smooth endoplasmic reticulum
C)ribosomes
D)nucleoli

Accepted Answer

Translation is the process of protein synthesis from an mRNA template, and it occurs on ribosomes. Ribosomes are tiny factories made up of RNA and proteins, and they are the site of translation. Choice A, lysosomes, are responsible for intracellular digestion, while smooth endoplasmic reticulum (choice B) plays a role in lipid metabolism and detoxification. Nucleoli (choice D) are responsible for ribosome biogenesis.

Question 12

During translation,what is the CORRECT order of events that occur as an amino acid is added?
A)codon recognition,peptide bond formation,translocation
B)translocation,codon recognition,termination
C)initiation,codon recognition,termination
D)peptide bond formation,translocation,codon recognition

Accepted Answer

The correct order of events during translation is codon recognition, peptide bond formation, and translocation. During codon recognition, the ribosome matches the codon on the mRNA molecule to the appropriate tRNA molecule with the corresponding anticodon. Peptide bond formation occurs when the amino acid carried by the tRNA is added to the growing polypeptide chain. Translocation then moves the ribosome along the mRNA to the next codon, where the process is repeated. Termination occurs when a stop codon is reached.

Question 13

Translation converts the information stored in ________ to ________.
A)DNA...RNA
B)RNA...a polypeptide
C)DNA...a polypeptide
D)RNA...DNA

Accepted Answer

Translation is the process of converting the information stored in RNA to a polypeptide (protein). RNA serves as the messenger between DNA (which contains the genetic information) and the ribosome (which synthesizes the protein). Therefore, option B is the correct answer as it represents the accurate sequence of events during translation.

Question 14

A(n)________ is to bacteria as a ________ is to animal cells.
A)retrovirus...virus
B)phage...prophage
C)prophage...provirus
D)RNA virus...DNA virus

Accepted Answer

The answer of A(n)________ is to bacteria as a ________...

Question 15

The RNA that is translated into a polypeptide is ________ RNA.
A)viral
B)ribosomal
C)transfer
D)messenger

Accepted Answer

Messenger RNA (mRNA) carries the genetic information from DNA to ribosomes where it is translated into a polypeptide chain. Viral RNA, ribosomal RNA (rRNA), and transfer RNA (tRNA) are all important types of RNA but do not directly code for proteins in the same way as mRNA.

Question 16

HIV (human immunodeficiency virus)must use its own ________ to reproduce.
A)DNA polymerase
B)reverse transcriptase
C)RNA polymerase
D)tRNA

Accepted Answer

HIV is a retrovirus, which means it contains RNA instead of DNA as its genetic material. To reproduce, it must first convert its RNA into DNA using the enzyme reverse transcriptase. This newly formed DNA can then integrate itself into the host cell's genome, allowing the virus to replicate and spread. Therefore, the best choice is B) reverse transcriptase.

Question 17

How can bacteriophage DNA be spread from cell to cell without causing cell death?
A)by altering the way a cell splices its RNA
B)via a lytic cycle
C)via a lysogenic cycle
D)by changing the length of its DNA molecules

Accepted Answer

Bacteriophage DNA can be spread from cell to cell without causing cell death via a lysogenic cycle. In this cycle, the phage DNA integrates into the host cell's genome and replicates along with it. The host cell continues to divide normally, and the phage DNA is passed on to daughter cells as long as the host cell survives. This allows for the slow, steady spread of the phage DNA through a population without the rapid cell death characteristic of the lytic cycle.

Question 18

As an experiment,you infect bacteria with an unknown virus to see how the bacteriophage affects the bacteria.After a few days,you notice that the bacterial population is growing normally and that the cells appear healthy.Assuming that the infection occurred,what can you conclude from your observations?
A)The virus is a bacteriophage that is reproducing the lytic cycle.
B)The virus is a retrovirus that is reproducing the lytic cycle.
C)The virus is a bacteriophage that is reproducing the lysogenic cycle.
D)The virus is a retrovirus that is reproducing the lysogenic cycle.

Accepted Answer

If the bacterial population is growing normally and the cells appear healthy after a few days, it is likely that the virus is a bacteriophage reproducing the lysogenic cycle. In lysogeny, the viral DNA integrates into the bacterial chromosome and remains dormant until triggered by a certain stimulus, such as stress or damage to the host cell. Therefore, the bacteriophage remains in the host cell without killing it immediately, allowing the bacteria to continue to grow and appear healthy.

Question 19

The DNA codon AGT codes for an amino acid carried by a tRNA with the anticodon ________.
A)TCU
B)AGU
C)TCA
D)AGT

Accepted Answer

The anticodon on the tRNA that matches with the DNA codon AGT is AGU. This is because the anticodon on a tRNA molecule is complementary to the codon on the mRNA molecule. Since the DNA codon AGT would be transcribed into the mRNA codon UCA (due to complementary base pairing between A and U, and G and C), the anticodon on the tRNA that matches with UCA would be AGU (due to complementary base pairing between A and U, and G and C).

Question 20

A mutation within a gene that will insert a premature stop codon in mRNA would ________.
A)result in a longer polypeptide chain
B)result in a shortened polypeptide chain
C)change the location at which transcription of the next gene begins
D)have the same effect as deleting a single nucleotide in the gene

Accepted Answer

The premature stop codon would cause translation to terminate early, resulting in a shortened polypeptide chain.

Quiz 10: The Structure and Function of Dna

What is the smallest number of nucleotides that must be added or subtracted to change the triplet grouping of the genetic message?

Scientific research companies sell kits that allow researchers to produce proteins in test tubes via a process known as "in vitro translation." Which one of following components is NOT needed in these kits?

The absence of a terminator in transcription will result in ________.

Plant viruses ________.

The CORRECT sequence of events occurring during transcription is ________.

The expressed (coding) regions of eukaryotic genes are called ________.

Mad cow disease is caused by

What is the ultimate source of all diversity?

Peptide bonds form between ________.

What protects mRNA from attack by cellular enzymes?

Where is translation accomplished?

During translation,what is the CORRECT order of events that occur as an amino acid is added?

Translation converts the information stored in to .

A(n) is to bacteria as a is to animal cells.

The RNA that is translated into a polypeptide is ________ RNA.

HIV (human immunodeficiency virus) must use its own ________ to reproduce.

How can bacteriophage DNA be spread from cell to cell without causing cell death?

The DNA codon AGT codes for an amino acid carried by a tRNA with the anticodon ________.

A mutation within a gene that will insert a premature stop codon in mRNA would ________.