Question 1

Which statement about methionine is false?

Accepted Answer

A)  It is always the first amino acid in a new polypeptide chain in eukaryotes. 
B)  It is always the first amino acid in mature proteins in eukaryotes. 
C)  In a modified form,it is the first amino acid in a new polypeptide chain in bacteria. 
D)  Transfer RNAs that bind to start codons are charged with methionine. 
E)  It is encoded by the start codon. 
A)  It is always the first amino acid in a new polypeptide chain in eukaryotes. 
B)  It is always the first amino acid in mature proteins in eukaryotes. 
C)  In a modified form,it is the first amino acid in a new polypeptide chain in bacteria. 
D)  Transfer RNAs that bind to start codons are charged with methionine. 
E)  It is encoded by the start codon.

Question 2

Imagine that a novel life form is found deep within Earth's crust.It uses DNA as an information storage molecule,and transcription and translation occur as in other life forms with one exception: a codon for this organism is just two bases in length.What is the maximum number of different amino acids that could be encoded from such a genetic code?

Accepted Answer

A)  8 
B)  16 
C)  24 
D)  32 
E)  64 
A)  8 
B)  16 
C)  24 
D)  32 
E)  64

Question 3

In bacteria,_______ kind(s)of RNA polymerase catalyze(s)the synthesis of RNA from DNA.

Accepted Answer

A)  one 
B)  three 
C)  four 
D)  five 
E)  six 
A)  one 
B)  three 
C)  four 
D)  five 
E)  six

Question 4

Use the following to answer questions :
Suppose that a wild-type bacterium can synthesize substance D,but various mutant strains cannot.We know that substance D is synthesized from substance X in a pathway that involves three intermediate substances (A,B,and C),but we do not know the order of the steps in the pathway.Below is a table of four different mutant strains that have been tested for their ability to grow on the various substances.The plus sign means that the strain can grow on that substance;the negative sign means that the strain cannot grow on that substance.  
-According to the data above,what is the most likely order of the pathway?

Accepted Answer

A)  A,B,C,D 
B)  A,C,B,D 
C)  B,A,C,D 
D)  C,B,A,D 
E)  C,A,B,D 
A)  A,B,C,D 
B)  A,C,B,D 
C)  B,A,C,D 
D)  C,B,A,D 
E)  C,A,B,D

Question 5

What is the most likely reason that alkaptonuria is a recessive disease?

Accepted Answer

A)  The mutant phenotype arises from a change in the protein's amino acid sequence. 
B)  More than half the typical amount of homogentisic acid oxidase is needed to break down the toxin by-product. 
C)  Having half the typical amount of homogentisic acid oxidase is sufficient to break down the toxin by-product. 
D)  Homogentisic acid oxidase occurs early in the metabolic pathway. 
E)  Homogentisic acid oxidase occurs late in the metabolic pathway. 
A)  The mutant phenotype arises from a change in the protein's amino acid sequence. 
B)  More than half the typical amount of homogentisic acid oxidase is needed to break down the toxin by-product. 
C)  Having half the typical amount of homogentisic acid oxidase is sufficient to break down the toxin by-product. 
D)  Homogentisic acid oxidase occurs early in the metabolic pathway. 
E)  Homogentisic acid oxidase occurs late in the metabolic pathway.

Question 6

The three codons in the genetic code that do not specify amino acids are called

Accepted Answer

A)  missense codons. 
B)  start codons. 
C)  stop codons. 
D)  promoters. 
E)  initiator codons. 
A)  missense codons. 
B)  start codons. 
C)  stop codons. 
D)  promoters. 
E)  initiator codons.

Question 7

UGU and UGC both code for cysteine.A change from UGU to UGC would thus be a(n)_______ mutation.

Accepted Answer

A)  missense 
B)  nonsense 
C)  ambiguous 
D)  silent 
E)  frame-shift 
A)  missense 
B)  nonsense 
C)  ambiguous 
D)  silent 
E)  frame-shift

Question 8

Ribosomes are a collection of _______ that are needed for _______.

Accepted Answer

A)  small proteins;translation 
B)  proteins and small RNAs;translation 
C)  proteins and tRNAs;transcription 
D)  proteins and mRNAs;translation 
E)  mRNAs and tRNAs;translation 
A)  small proteins;translation 
B)  proteins and small RNAs;translation 
C)  proteins and tRNAs;transcription 
D)  proteins and mRNAs;translation 
E)  mRNAs and tRNAs;translation

Question 9

Which principle does the genetics of hemoglobin in humans illustrate?

Accepted Answer

A)  Not all genes code for enzymes. 
B)  One gene codes for one enzyme. 
C)  All mutations of the same gene have the same phenotypic effect. 
D)  Not all genes code for polypeptides. 
E)  Proteins can code for DNA. 
A)  Not all genes code for enzymes. 
B)  One gene codes for one enzyme. 
C)  All mutations of the same gene have the same phenotypic effect. 
D)  Not all genes code for polypeptides. 
E)  Proteins can code for DNA.

Question 10

Which finding would be the most plausible?

Accepted Answer

A)  A pre-RNA strand is longer than the corresponding mature mRNA. 
B)  A pre-RNA strand is shorter than the corresponding mature mRNA. 
C)  The nucleotides of a pre-RNA strand are in a different order from those of the corresponding mature mRNA. 
D)  A mature mRNA strand contains more introns than the corresponding pre-RNA. 
E)  Introns scramble the order of genes. 
A)  A pre-RNA strand is longer than the corresponding mature mRNA. 
B)  A pre-RNA strand is shorter than the corresponding mature mRNA. 
C)  The nucleotides of a pre-RNA strand are in a different order from those of the corresponding mature mRNA. 
D)  A mature mRNA strand contains more introns than the corresponding pre-RNA. 
E)  Introns scramble the order of genes.

Question 11

The three-dimensional structure of tRNA is maintained by

Accepted Answer

A)  peptide bonds. 
B)  hydrogen bonds. 
C)  disulfide bridges. 
D)  phosphodiester bonds. 
E)  glycosidic linkages. 
A)  peptide bonds. 
B)  hydrogen bonds. 
C)  disulfide bridges. 
D)  phosphodiester bonds. 
E)  glycosidic linkages.

Question 12

MRSA is a variant of

Accepted Answer

A)  Escherichia coli. 
B)  Staphylococcus aureus. 
C)  Bacillus anthracis. 
D)  Mycobacterium riggeti. 
E)  Mycobacterium roochi. 
A)  Escherichia coli. 
B)  Staphylococcus aureus. 
C)  Bacillus anthracis. 
D)  Mycobacterium riggeti. 
E)  Mycobacterium roochi.

Question 13

Mapping studies have determined that within a group of mutants with the same growth requirements (i.e. ,the same overt phenotype),individual mutations are on different chromosomes.This indicates that

Accepted Answer

A)  the same gene governs all the steps in a particular biological pathway. 
B)  different genes can govern different individual steps in the same biological pathway. 
C)  different genes govern the same step in a particular biological pathway. 
D)  all biological pathways are governed by different genes. 
E)  genes do not govern steps in biological pathways,but proteins do. 
A)  the same gene governs all the steps in a particular biological pathway. 
B)  different genes can govern different individual steps in the same biological pathway. 
C)  different genes govern the same step in a particular biological pathway. 
D)  all biological pathways are governed by different genes. 
E)  genes do not govern steps in biological pathways,but proteins do.

Question 14

The anticodon 3'-AUC-5' would pair with the codon

Accepted Answer

A)  5'-ATC-3'. 
B)  5'-AUC-3'. 
C)  5'-UAG-3'. 
D)  5'-TAG-3'. 
E)  5'-CAU-3'. 
A)  5'-ATC-3'. 
B)  5'-AUC-3'. 
C)  5'-UAG-3'. 
D)  5'-TAG-3'. 
E)  5'-CAU-3'.

Question 15

The "adapters" that allow translation of the four-letter nucleic acid language into the 20-letter protein language are called

Accepted Answer

A)  aminoacyl tRNA synthetases. 
B)  transfer RNAs. 
C)  ribosomal RNAs. 
D)  messenger RNAs. 
E)  ribosomes. 
A)  aminoacyl tRNA synthetases. 
B)  transfer RNAs. 
C)  ribosomal RNAs. 
D)  messenger RNAs. 
E)  ribosomes.

Question 16

Which statement about tRNAs is false?

Accepted Answer

A)  Any particular tRNA binds to one and only one amino acid. 
B)  tRNAs bind physically to mRNA. 
C)  The three-dimensional structure of tRNA results from hydrogen bonding between complementary bases. 
D)  tRNAs interact with ribosomes. 
E)  During elongation,the anticodon of an incoming tRNA first binds to the codon at the P site. 
A)  Any particular tRNA binds to one and only one amino acid. 
B)  tRNAs bind physically to mRNA. 
C)  The three-dimensional structure of tRNA results from hydrogen bonding between complementary bases. 
D)  tRNAs interact with ribosomes. 
E)  During elongation,the anticodon of an incoming tRNA first binds to the codon at the P site.

Question 17

If a 5'-to-3' strand of DNA has the sequence GTCTATGCATTA,what is the template DNA strand that would be used for transcription?

Accepted Answer

A)  5'-GTCTATGCATTA-3' 
B)  5'-CAGATACGTAAT-3' 
C)  3'-GTCTATGCATTA-5' 
D)  3'-CAGATACGTAAT-5' 
E)  5'-GUCUAUGCAUUA-3' 
A)  5'-GTCTATGCATTA-3' 
B)  5'-CAGATACGTAAT-3' 
C)  3'-GTCTATGCATTA-5' 
D)  3'-CAGATACGTAAT-5' 
E)  5'-GUCUAUGCAUUA-3'

Question 18

The _______ strand of DNA is transcribed to produce an RNA strand by DNA bases pairing with _______ bases of RNA.

Accepted Answer

A)  coding;the same 
B)  coding;complementary 
C)  coding;reverse 
D)  template;the same 
E)  template;complementary 
A)  coding;the same 
B)  coding;complementary 
C)  coding;reverse 
D)  template;the same 
E)  template;complementary

Question 19

RNA polymerase is a

Accepted Answer

A)  polysaccharide. 
B)  lipid. 
C)  protein. 
D)  nucleic acid. 
E)  carbohydrate/lipid mixture. 
A)  polysaccharide. 
B)  lipid. 
C)  protein. 
D)  nucleic acid. 
E)  carbohydrate/lipid mixture.

Question 20

Suppose that a certain mRNA is transcribed at a normal rate in the nucleus,but it is found at very low levels in the cytoplasm.Which of the following would be the most plausible explanation for this phenomenon?

Accepted Answer

A)  A defect in the addition of the poly A tail on the pre-mRNA 
B)  A defect in a spliceosome 
C)  A defect in nucleic acid hybridization 
D)  Overactive termination 
E)  A defect in the promoter 
A)  A defect in the addition of the poly A tail on the pre-mRNA 
B)  A defect in a spliceosome 
C)  A defect in nucleic acid hybridization 
D)  Overactive termination 
E)  A defect in the promoter

Exam 10: From Dna to Protein: Gene Expression

Which statement about methionine is false?

In bacteria,_______ kind(s)of RNA polymerase catalyze(s)the synthesis of RNA from DNA.

What is the most likely reason that alkaptonuria is a recessive disease?

The three codons in the genetic code that do not specify amino acids are called

UGU and UGC both code for cysteine.A change from UGU to UGC would thus be a(n)_______ mutation.

Ribosomes are a collection of _______ that are needed for _______.

Which principle does the genetics of hemoglobin in humans illustrate?

Which finding would be the most plausible?

The three-dimensional structure of tRNA is maintained by

MRSA is a variant of

Mapping studies have determined that within a group of mutants with the same growth requirements (i.e. ,the same overt phenotype),individual mutations are on different chromosomes.This indicates that

The anticodon 3'-AUC-5' would pair with the codon

The "adapters" that allow translation of the four-letter nucleic acid language into the 20-letter protein language are called

Which statement about tRNAs is false?

If a 5'-to-3' strand of DNA has the sequence GTCTATGCATTA,what is the template DNA strand that would be used for transcription?

The _______ strand of DNA is transcribed to produce an RNA strand by DNA bases pairing with _______ bases of RNA.

RNA polymerase is a

Suppose that a certain mRNA is transcribed at a normal rate in the nucleus,but it is found at very low levels in the cytoplasm.Which of the following would be the most plausible explanation for this phenomenon?

Introduction

The Chemistry and Energy of Life

Nucleic Acids, Proteins, and Enzymes

Cells: the Working Units of Life

Cell Membranes and Signaling

Pathways That Harvest and Store Chemical Energy

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

DNA and Its Role in Heredity

Regulation of Gene Expression

Genomes

Biotechnology

Genes, Development, and Evolution

Processes of Evolution

Reconstructing and Using Phylogenies

Speciation

The History of Life on Earth

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

The Evolution of Plants

The Evolution and Diversity of Fungi

Animal Origins and Diversity

The Plant Body

Plant Nutrition and Transport

Plant Growth and Development

Reproduction of Flowering Plants

Plants in the Environment

Fundamentals of Animal Function

Nutrition and Digestion

Breathing

Circulation

Muscle and Movement

Neurons, Sense Organs, and Nervous Systems

Nervous and Endocrine Control

Water and Salts: Excretion

Animal Reproduction

Animal Development

Immunology: Animal Defense Systems

Animal Behavior

The Distribution of Earths Ecological Systems

Populations

Ecological and Evolutionary Consequences of Interactions Within and Among Species

Ecological Communities

The Global Ecosystem

Filters

Ribosomes are a collection of _ that are needed for _.

The _ strand of DNA is transcribed to produce an RNA strand by DNA bases pairing with _ bases of RNA.