Deck 14: From Dna to Protein

Question 1

DNA from bacteria differs from DNA in humans in which of the following ways?

A)base composition
B)sugar-phosphate linkage
C)nucleotide sequence
D)bonding of the helix
E)all of these

Answer 1

C

Question 2

Which substance is found in RNA but not in DNA?

A)thymine
B)deoxyribose
C)uracil
D)guanine
E)cytosine

Answer 2

C

Question 3

Transcription

A)involves both strands of DNA as templates.
B)uses the enzyme DNA polymerase.
C)results in a double-stranded end product.
D)produces three different types of RNA molecules.
E)fits all of these descriptions.

Answer 3

D

Question 4

All the different kinds of RNA are transcribed in the

A)mitochondria.
B)cytoplasm.
C)ribosomes.
D)nucleus.
E)endoplasmic reticulum.

Question 5

A linear stretch of DNA that specifies the sequence of amino acids in a polypeptide is called a(n)

A)codon.
B)intron.
C)messenger.
D)gene.
E)enzyme.

Question 6

The RNA molecule is made up of how many strands?

A)1
B)2
C)3
D)6
E)12

Question 7

The DNA molecule usually is made up of how many strands?

A)1
B)2
C)3
D)6
E)12

Question 8

The changing of a business letter from shorthand to typewritten copy is analogous to

A)translation of mRNA.
B)transcription of DNA.
C)protein synthesis.
D)deciphering the genetic code.
E)replication of DNA.

Question 9

Ricin is

A)a substance found in castor bean seeds.
B)a polysaccharide extracted from rice.
C)an ingredient in many paints and cosmetics.
D)a protein that inactivates ribosomes.
E)a substance found in castor bean seeds and a protein that inactivates ribosomes.

Question 10

DNA and RNA are alike in

A)the pentose sugar.
B)all the nitrogenous bases used to assemble the genetic code.
C)the number of strands.
D)their function in genetics.
E)none of these.

Question 11

The form of RNA that carries the code from DNA to the site of protein assembly is called

A)messenger RNA.
B)nuclear RNA.
C)ribosomal RNA.
D)transfer RNA.
E)structural RNA.

Question 12

The synthesis of an RNA molecule from a DNA template strand is

A)replication.
B)translation.
C)transcription.
D)DNA synthesis.
E)metabolism.

Question 13

The nitrogenous base found in RNA but not in DNA is

A)adenine.
B)cytosine.
C)guanine.
D)uracil.
E)thymine.

Question 14

__________ molecules carry protein-assembly instructions from the nucleus to the cytoplasm.

A)Template DNA
B)Messenger RNA
C)Transfer RNA
D)Ribosomal RNA
E)All of these

Question 15

The two steps of transcription followed by translation

A)explain the structural complexity of genes.
B)describe the flow of information.
C)are based upon the role of proteins in controlling life.
D)do not explain how genes function.
E)explain evolution in terms of molecular biology.

Question 16

The relationship between strands of RNA and DNA is

A)antagonistic.
B)opposite.
C)complementary.
D)an exact duplicate.
E)unrelated.

Question 17

The helix structure on the right of the above figure represents

A)DNA.
B)RNA.
C)lipid.
D)protein.
E)phospholipid.

Question 18

The nitrogenous base found in DNA but not in RNA is

A)adenine.
B)cytosine.
C)guanine.
D)uracil.
E)thymine.

Question 19

Transcription

A)occurs on the surface of the ribosome.
B)is the final process in the assembly of a protein.
C)occurs during the synthesis of any type of RNA from a DNA template.
D)is catalyzed by DNA polymerase.
E)fits all of these descriptions.

Question 20

Uracil will pair with

A)ribose.
B)adenine.
C)cytosine.
D)thymine.
E)guanine.

Question 21

Of all the different codons that exist, three of them

A)are involved in mutations.
B)do not specify a particular amino acid.
C)cannot be copied.
D)provide instructions such as STOP.
E)do not specify a particular amino acid and provide instructions such as STOP.

Question 22

If the DNA triplets are ATG-CGT, the tRNA anticodons are

A)AUG-CGU.
B)ATG-CGT.
C)UAC-GCA.
D)UAG-CGU.
E)all of these.

Question 23

In transcription,

A)several amino acids are assembled by the messenger RNA molecules at one time.
B)a special sequence called a promoter is necessary for transcription to begin.
C)certain polypeptide sequences are governed by one ribosome, whereas other sequences are produced by multiple ribosomes.
D)the transfer RNA molecules arrange the messenger RNA codons into the appropriate sequence.
E)all of these occur.

Question 24

Which of the following dominates the process of transcription?

A)RNA polymerase
B)DNA polymerase
C)phenylketonuria
D)transfer RNA
E)all of these

Question 25

The insertion of how many nucleotides into a genetic sequence does less damage to the code than the insertion of other numbers of nucleotides?

A)1
B)2
C)3
D)4
E)5

Question 26

In transcription,

A)several RNA molecules are made from the same DNA molecule.
B)a promoter sequence is needed.
C)DNA produces messenger RNA.
D)a specific enzyme called RNA polymerase is required.
E)all of these occur.

Question 27

If the DNA triplets are ATG-CGT, the mRNA codons are

A)AUG-CGU.
B)ATG-CGT.
C)UAC-GCA.
D)UAG-CGU.
E)all of these.

Question 28

The portion of the DNA molecule that is not translated and is a noncoding portion of DNA is composed of

A)introns.
B)anticodons.
C)exons.
D)transcriptons.
E)exons and transcriptons.

Question 29

Before leaving the nucleus, the RNA molecule

A)acquires a poly-A tail.
B)is released from the STOP signal on the template.
C)becomes capped.
D)is stripped of its introns.
E)does all of these.

Question 30

If each nucleotide coded for a single amino acid, how many different types of amino acids could be combined to form proteins?

A)4
B)16
C)20
D)64
E)none of these

Question 31

Which of the following can NOT be an RNA transcript?

A)AUGCUU
B)ATGCGT
C)UACGCA
D)UAGCGU
E)GCGUUU

Question 32

In this depiction of transcription, the __________ strand is __________ because it __________.

A)upper; RNA; is single-stranded.
B)lower; RNA; contains uracil.
C)lower; RNA; contains thymine.
D)upper; RNA; has no uracil (U).
E)lower; DNA; contains adenine (A).

Question 33

Before messenger RNA is mature,

A)all exons are deleted and removed.
B)a cap and a tail are provided.
C)anticodons are assembled.
D)the transfer RNA transfers the messenger RNA to the ribosome.
E)the single RNA strand duplicates itself in much the same way as DNA.

Question 34

There are how many different kinds of RNA codons?

A)3
B)12
C)28
D)64
E)120

Question 35

There are how many different kinds of RNA nucleotides?

A)3
B)4
C)5
D)6
E)12

Question 36

The portion of the DNA molecule that is translated is composed of

A)introns.
B)anticodons.
C)exons.
D)transcriptons.
E)exons and transcriptons.

Question 37

There are how many different kinds of amino acids in proteins?

A)3
B)6
C)12
D)20
E)28

Question 38

Each "word" in the mRNA language consists of how many letters?

A)3
B)4
C)5
D)more than 5
E)all of these

Question 39

The genetic code is made up of codons consisting of how many nucleotides?

A)2
B)3
C)5
D)6
E)9

Question 40

Transcription starts at a region of DNA called a(n)

A)sequencer.
B)promoter.
C)activator.
D)terminator.
E)transcriber.

Question 41

During the termination stage

A)a STOP codon enters the ribosome.
B)release factors bind the ribosome.
C)mRNA detaches from the ribosome and the polypeptide chain.
D)ribosomal subunits separate.
E)all of these occur.

Question 42

Frameshift mutations may involve

A)substitution of nucleotides.
B)substitution of codons.
C)substitution of amino acids.
D)addition or deletion of one or more base pairs.
E)none of these.

Question 43

Which structure is involved in the initiation stage?

A)a specific tRNA
B)an mRNA transcript
C)a small ribosomal subunit
D)a large ribosomal subunit
E)all of these

Question 44

In correct order, the three stages of translation are

A)initiation, replication, and termination.
B)elongation, peptide bond formation, and codon-anticodon pairing.
C)initiation, elongation, and termination.
D)termination, initiation, and replication.
E)none of these.

Question 45

The maximum number of tRNAs that can be on one ribosome at one time is

A)2.
B)3.
C)4³.
D)unlimited.
E)unknown.

Question 46

Which event of translation is shown here?

A)initiation
B)elongation
C)termination
D)peptide bond formation
E)elongation and peptide bond formation

Question 47

Transfer RNA differs from other types of RNA because it

A)transfers genetic instructions from cell nucleus to cytoplasm.
B)specifies the amino acid sequence of a particular protein.
C)carries an amino acid at one end.
D)contains codons.
E)does none of these.

Question 48

All mRNA transcripts begin with

A)methionine.
B)a ribosome.
C)AUG.
D)the P site.
E)an anticodon.

Question 49

Which of the following statements is false?

A)In chain elongation, the amino acids are added to the chain according to the codon sequence in the messenger RNA.
B)Several ribosomes, called a polysome, can travel along the messenger RNA molecule, translating it at the same time.
C)The general shape of transfer RNA molecules is uniform.
D)Enzymes found in the ribosome catalyze the formation of the bonds in the new polypeptide.
E)None of these is false.

Question 50

Mutations can be

A)random.
B)beneficial.
C)lethal.
D)heritable.
E)all of these.

Question 51

Which of the following statements is true?

A)Gene mutations occur independently of each other.
B)Gene mutations are relatively rare.
C)Ionizing radiation causes chromosomal damage and free radical formation.
D)Mutations are random; that is, it is impossible to predict exactly when a specific gene will mutate, but an expected frequency can be assigned.
E)All of these are true.

Question 52

The structure in the above figure demonstrates which of the following ?

A)transcription and translation occur simultaneously on a single strand
B)ribosomes attached to a strand of DNA
C)a small ribosomal subunit
D)multiple ribosomes on a strand of mRNA
E)all of these

Question 53

Which event may occur in all viruses, prokaryotes, and eukaryotes?

A)duplication
B)aneuploidy
C)translocation
D)mutation
E)none of these

Question 54

Which of the following carries amino acids to ribosomes, where amino acids are linked into the primary structure of a polypeptide?

A)mRNA
B)tRNA
C)hnRNA
D)rRNA
E)all of these

Question 55

Which stage of translation is shown here?

A)initiation
B)elongation
C)termination
D)peptide bond formation
E)polysome activity

Question 56

Eukaryotic ribosomes function as

A)a single unit.
B)two-part units.
C)three-part units.
D)four-part units.
E)a multidivisional unit.

Question 57

Which event occurs during the elongation stage?

A)Peptide bonds form.
B)Free amino acids bind to the mRNA binding site.
C)Anticodons bind to complementary codons.
D)A STOP codon enters the ribosome.
E)Peptide bonds form, and anticodons bind to complementary codons.

Question 58

A gene mutation

A)is a change in the nucleotide sequence of DNA.
B)may be caused by environmental agents.
C)may arise spontaneously.
D)can occur in any organism.
E)is described by all of these.

Question 59

A polysome is

A)one of the units of a ribosome.
B)the nuclear organelle that synthesizes RNA.
C)an organelle that functions similarly to a ribosome during meiosis.
D)the two units of a ribosome considered together.
E)an mRNA molecule with several ribosomes attached.

Question 60

Ribosomal subunits

A)come together in threes to form functional units.
B)are composed of mRNA and structural proteins.
C)are synthesized in the cytoplasm.
D)converge only when mRNA is to be translated.
E)are transcribed from the complementary strand of DNA that is used for tRNA transcription.

Question 61

Sickle-cell anemia has been traced to what type of mutation?

A)frameshift
B)transposable element
C)mutagenic
D)base-pair substitution
E)viral

Question 62

The difference between normal and sickle-cell hemoglobin is based upon

A)the number of amino acids in the molecule.
B)the substitution of one amino acid for another.
C)the number and orientation of the amino acid chains attached to the heme portion of the molecule.
D)the number of oxygen molecules that can be carried.
E)the type of bone marrow that produces it.

Question 63

In a mutation,

A)the new codon may specify a different amino acid but may not change the function of the new protein produced.
B)the new codon may specify the same amino acid as the old codon.
C)the new codon and resulting amino acid may destroy the function of the protein specified.
D)the new codon may specify no amino acid.
E)all of these may be true.