Deck 12: How Genes Work

Question 1

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

Answer 1

D

Question 2

Which of the following cannot be a product of transcription?

A) mRNA
B) Protein
C) rRNA
D) tRNA

Answer 2

B

Question 3

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

Answer 3

B

Question 4

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

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

Question 5

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

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

Question 6

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

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

Question 7

The process of bringing in the appropriate amino acid into position along the mRNA in the cytoplasm is:

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

Question 8

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

A) about 1.5%
B) about 20%
C) about 35%
D) about 50%
E) about 75%

Question 9

A(n)____________ is a piece of DNA with a group of genes that are transcribed together as a unit.

A) promoter
B) repressor
C) operator
D) operon

Question 10

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 11

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 eukarya use another.

Question 12

How many different codons are possible with the four different nucleotides?

A) 12
B) 24
C) 55
D) 64
E) 128

Question 13

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 14

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

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

Question 15

When mRNA leaves the cell's nucleus,it next becomes associated with:

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

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

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 18

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

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

Question 19

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

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 three types of RNA involved in protein synthesis are mRNA,_______________,and ________________.

Question 22

Small interfering RNAs can alter gene expression by targeting mRNA for destruction or by blocking translation of a mRNA.

Question 23

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

Question 24

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

A) there is DNA transcription
B) there is alternative splicing of genes
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 25

For a gene to be transcribed,the RNA polymerase has to bind to a(n)_____ sequence of nucleotides on the DNA.

A) repressor
B) operon
C) promotor
D) initiator
E) elongation

Question 26

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 27

The use of information in DNA to produce proteins in the cytoplasm is ____________.

Question 28

The genetic code is universal,the same in practically all organisms.

Question 29

Describe the differences between DNA and RNA.

Question 30

A type of DNA sequence that expands access to a gene to promote its expression is a(n)_______________.

Question 31

The genetic code is a ____________ code.

Question 32

Due to _________,the 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 33

The three nucleotide sequence on mRNA is called an anticodon.

Question 34

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 35

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.