Deck 12: How Genes Work

Question 1

The use of DNA information to direct the production of particular proteins is called

A) transcription.
B) translation.
C) gene expression.
D) replication.
E) polymerization.

Answer 1

C

Question 2

How many nucleotides comprise a codon?

A) 3
B) 6
C) 20
D) 64
E) 128

Answer 2

A

Question 3

The nucleotide sequences on DNA that actually have information encoding a sequence of amino acids are

A) introns.
B) exons.
C) proteins.
D) enhancers.

Answer 3

B

Question 4

In humans,what percent of a gene is devoted to the exons that encode proteins?

A) About 5%
B) About 20%
C) About 35%
D) About 50%
E) About 75%

Question 5

The mRNA has a three-nucleotide sequence called a(n)_________,while the molecule transporting the amino acid has a complementary sequence called a(n)_______________.

A) anticodon;codon
B) triplet code;stop codon
C) base;complementary base
D) codon;anticodon

Question 6

The process of bringing the appropriate amino acid into position along the mRNA and building a polypeptide is

A) translation.
B) transcription.
C) transduction.
D) promotion.

Question 7

Said simply,the Central Dogma of gene expression is as follows: DNA is transcribed to produce mRNA,which is translated to produce

A) promoters.
B) nucleosomes.
C) operators.
D) proteins.

Question 8

The molecule that carries each amino acid to its correct position along mRNA in the cytoplasm is

A) ribosomal RNA.
B) tRNA.
C) mRNA.
D) ATP.

Question 9

The site where RNA polymerase attaches to the DNA molecule to start the formation of mRNA is called a(n)

A) operon.
B) exon.
C) promoter.
D) operator.

Question 10

To turn genes off,a regulatory protein called a __________ is bound to a regulatory site so that RNA polymerase is blocked.

A) repressor
B) translator
C) signal molecule
D) operon

Question 11

In eukaryotes,the RNA copy of DNA that leaves the nucleus and travels to the cytoplasm to make proteins is

A) ribosomal RNA.
B) tRNA.
C) mRNA.
D) RNA polymerase.

Question 12

Which site on the ribosome does the new tRNA bring an amino acid to?

A) A
B) P
C) E
D) C

Question 13

When mRNA leaves a eukaryotic cell's nucleus,it next becomes associated with

A) tRNA.
B) endoplasmic reticulum.
C) a ribosome.
D) proteins.

Question 14

Which is incorrect about the lac operon?

A) A repressor binds to the operator.
B) RNA polymerase binds to the promoter.
C) CAP blocks RNA polymerase.
D) The operon is transcribed if RNA polymerase can bind.
E) It is an example of prokaryotic transcriptional control.

Question 15

Which of the following is correct about the genetic code?

A) All prokaryotes use one code and all eukaryotes use another.
B) All living things use the same genetic code.
C) Protists use a different code than other kingdoms.
D) Fungi and animals use the same code,but plants use another.
E) Archaea and bacteria use one code and other kingdoms use another.

Question 16

In eukaryotes,transcription takes place in the _________ and translation takes place in the ________.

A) cytoplasm;nucleus
B) nucleus;cytoplasm
C) cytoplasm;cytoplasm
D) nucleoid;cytoplasm
E) nucleus;nucleus

Question 17

If an mRNA codon reads UAC,its complementary anticodon will be

A) AUG.
B) CAG.
C) ATG.
D) TUC.

Question 18

The primary RNA transcript is

A) tRNA before it forms its hairpin loops.
B) rRNA before it forms the ribosome.
C) mRNA after the introns have been removed.
D) mRNA before the introns have been removed.
E) mRNA before the exons have been removed.

Question 19

A group of DNA nucleotides that contains the information to produce a single polypeptide is a

A) base.
B) promoter.
C) codon.
D) gene.

Question 20

The bases of RNA are the same as those of DNA with the exception that RNA contains

A) cysteine instead of cytosine.
B) uracil instead of thymine.
C) cytosine instead of guanine.
D) uracil instead of adenine.

Question 21

The relationship between mRNA codons and amino acids is called the _______________.

Question 22

During protein synthesis,_______________ occurs in the nucleus as a copy of DNA is made into mRNA,and ______________ begins in the cytoplasm,when mRNA associates with a ribosome.

Question 23

The RNA codon GCA codes for the amino acid alanine.

Question 24

A type of DNA sequence where eukaryotic activators can bind and promote a gene's expression is called a(n)_______________,which is typically located far away from the gene.

Question 25

What is RNA interference?

A) When small RNAs form double-stranded RNA molecules that can regulate gene expression.
B) When proteins block the transcription of DNA in the nucleus.
C) When an RNA virus blocks the DNA replication of the host cell.
D) When tRNA attaches to the ribosome and blocks its movement along the mRNA.

Question 26

All of the following occur in both prokaryotes and eukaryotes except in eukaryotes,

A) there is DNA transcription.
B) there are introns.
C) in RNA,uracil replaces thymine.
D) translation occurs on a ribosome.
E) tRNA carries the amino acid to the mRNA to make polypeptides.

Question 27

Small interfering RNA can influence gene expression by affecting alternative splicing in eukaryotes.

Question 28

The three nucleotide sequence on mRNA is called an anticodon.

Question 29

Describe the differences between DNA and RNA.

Question 30

A mature mRNA transcript has had its ____________ removed during processing.

Question 31

Due to _________,the 20,000-25,000 genes of the human genome seem to encode as many as 120,000 different expressed mRNAs.

A) mutations
B) independent assortment
C) alternative splicing
D) recombination

Question 32

Genes that are transcribed together as a single unit in prokaryotes are found on DNA segments called ____________________.

Question 33

In prokaryotes,the primary function of gene control is to

A) respond quickly to the immediate environment.
B) adjust to available nutrients and oxygen.
C) alter transcription in irreversible and stable ways.
D) The first two are correct.
E) All of the above.

Question 34

Coiling of DNA into nucleosomes makes the DNA more accessible for binding of RNA polymerase and transcription factors.

Question 35

Explain why eukaryotic mRNA must be processed before it leaves the nucleus.

Question 36

Which of the following matches amino acids with their proper tRNAs in the cytoplasm?

A) mRNA
B) activating enzymes
C) rRNA
D) operators

Question 37

Biologists have found that the genetic code is universal,that the same triplet codons code for the same amino acids in almost all living things.Explain how this can be considered evidence for evolution.

Question 38

In eukaryotes,most of the protein-encoding information exists in DNA segments called introns.

Question 39

The three types of RNA involved in translation are mRNA,_______________,and ________________.

Question 40

During translation,a peptide bond forms between the incoming amino acid and the growing polypeptide chain at the ____________ site on the ribosome.