Question 1

Explain how Escherichia coli can grow with a doubling time of 20 minutes when chromosome replication takes 40 minutes.

Accepted Answer

Answers should demonstrate understanding

Question 2

In Bacteria,a chromosome can be distinguished from a plasmid,because a chromosome is a genetic element that

Accepted Answer

A) is circular. 
B) is linear. 
C) encodes for essential functional genes. 
D) replicates via a bidirectional fork. 
A) is circular. 
B) is linear. 
C) encodes for essential functional genes. 
D) replicates via a bidirectional fork.

Question 3

In ________ several ribosomes can simultaneously translate a single mRNA molecule in a complex called a(n)________.

Accepted Answer

A) prokaryotes / polysome 
B) eukaryotes / polysome 
C) prokaryotes / initiation complex 
D) eukaryotes / splicing complex 
A) prokaryotes / polysome 
B) eukaryotes / polysome 
C) prokaryotes / initiation complex 
D) eukaryotes / splicing complex

Question 4

Aminoacyl-tRNA synthetase catalyzes the reaction between the appropriate amino acid and ATP to form an activated amino acid: amino acid + ATP ↔ aminoacyl-AMP + P-P.

Accepted Answer

A) True 
 B)False

Question 5

Explain the concept of semiconservative replication and how simultaneous copying of both strands of DNA is accomplished in prokaryotic cells.

Accepted Answer

During replication,only one of the two s

Question 6

Explain the difference between an intrinsic terminator and a Rho-dependent termination site.

Accepted Answer

Intrinsic terminators occur at the nucle

Question 7

Speculate why the half-life of mRNA is short,while the half-lives of rRNA and tRNA are long.

Accepted Answer

An important feature present in rRNA and

Question 8

You are trying to design a protein that will be expressed in Escherichia coli and secreted outside of the cell for purification and use as a pharmaceutical.E.coli is a gram-negative cell and the protein folds after it has exited the cell.Which secretion system would work best for this project? Support your answer with evidence based on the properties of E.coli,the protein,and the secretion system.

Accepted Answer

Answers should refer to the fact that E.

Question 9

Which of the following statements is TRUE concerning mRNA?

Accepted Answer

A) mRNA has a very short half-life. 
B) mRNA has complex secondary structure. 
C) mRNA is catalytic. 
D) mRNA is the product of translation. 
A) mRNA has a very short half-life. 
B) mRNA has complex secondary structure. 
C) mRNA is catalytic. 
D) mRNA is the product of translation.

Question 10

Transposable elements are

Accepted Answer

A) segments of DNA that move from one site to another. 
B) transcribed genes. 
C) segments of RNA that are involved in transposing DNA into proteins. 
D) proteins that aid in the secretion of enzymes out of the cell. 
A) segments of DNA that move from one site to another. 
B) transcribed genes. 
C) segments of RNA that are involved in transposing DNA into proteins. 
D) proteins that aid in the secretion of enzymes out of the cell.

Question 11

Genes found on plasmids DO NOT impact metabolism or cellular structures.

Accepted Answer

A) True 
 B)False

Question 12

The codon on the ________ matches with the anticodon on the ________ to direct the addition of the correct amino acid to the growing polypeptide chain.

Accepted Answer

A) mRNA / tRNA 
B) tRNA / mRNA 
C) DNA / mRNA 
D) tRNA / rRNA 
A) mRNA / tRNA 
B) tRNA / mRNA 
C) DNA / mRNA 
D) tRNA / rRNA

Question 13

AT-rich DNA will denature/melt

Accepted Answer

A) at a higher temperature than GC-rich DNA. 
B) at a lower temperature than GC-rich DNA. 
C) usually at the same temperature as GC-rich DNA,with some minor variations. 
D) in accordance with the animal or plant from which it was taken. 
A) at a higher temperature than GC-rich DNA. 
B) at a lower temperature than GC-rich DNA. 
C) usually at the same temperature as GC-rich DNA,with some minor variations. 
D) in accordance with the animal or plant from which it was taken.

Question 14

DNA-binding proteins interact predominantly within which portion of a double-stranded DNA helix?

Accepted Answer

A) major groove 
B) minor groove 
C) 3' end 
D) supercoil 
A) major groove 
B) minor groove 
C) 3' end 
D) supercoil

Question 15

DNA replication always proceeds in only one direction because the ________ of the incoming nucleotide is attached to the free ________ of the growing DNA strand.

Accepted Answer

A) 5'-phosphate / 3'-hydroxyl 
B) 3'-phosphate / 5'-hydroxyl 
C) 5'-deoxyribose / 3'-base 
D) 3'-base / 5'-deoxyribose 
A) 5'-phosphate / 3'-hydroxyl 
B) 3'-phosphate / 5'-hydroxyl 
C) 5'-deoxyribose / 3'-base 
D) 3'-base / 5'-deoxyribose

Question 16

In all cells a gene encodes for

Accepted Answer

A) a protein (via mRN
A) . 
B) a tRNA. 
C) an rRNA. 
D) a protein,tRNA,or rRNA depending on the specific gene. 
A) a protein (via mRN
A) . 
B) a tRNA. 
C) an rRNA. 
D) a protein,tRNA,or rRNA depending on the specific gene.

Question 17

In nature,the predominant form of DNA is supercoiled in a negative direction.

Accepted Answer

A) True 
 B)False

Question 18

Speculate on why it can be problematic to copy and express genes from Bacteria into Eukarya.

Accepted Answer

Transcription in Bacteria is quite diffe

Question 19

Most prokaryotic genomes are double-stranded circular DNA.

Accepted Answer

A) True 
 B)False

Question 20

Some essential genes and DNA sequences in cells DO NOT encode for proteins but are still essential for cellular growth and replication.Give two examples of a gene or sequence of which this is true and explain why it is essential for growth or replication.

Accepted Answer

Answers to this question could use many

Exam 4: Molecular Biology

Explain how Escherichia coli can grow with a doubling time of 20 minutes when chromosome replication takes 40 minutes.

In Bacteria,a chromosome can be distinguished from a plasmid,because a chromosome is a genetic element that

In ________ several ribosomes can simultaneously translate a single mRNA molecule in a complex called a(n)________.

Aminoacyl-tRNA synthetase catalyzes the reaction between the appropriate amino acid and ATP to form an activated amino acid: amino acid + ATP ↔ aminoacyl-AMP + P-P.

Explain the concept of semiconservative replication and how simultaneous copying of both strands of DNA is accomplished in prokaryotic cells.

Explain the difference between an intrinsic terminator and a Rho-dependent termination site.

Speculate why the half-life of mRNA is short,while the half-lives of rRNA and tRNA are long.

Which of the following statements is TRUE concerning mRNA?

Transposable elements are

Genes found on plasmids DO NOT impact metabolism or cellular structures.

The codon on the ________ matches with the anticodon on the ________ to direct the addition of the correct amino acid to the growing polypeptide chain.

AT-rich DNA will denature/melt

DNA-binding proteins interact predominantly within which portion of a double-stranded DNA helix?

DNA replication always proceeds in only one direction because the ________ of the incoming nucleotide is attached to the free ________ of the growing DNA strand.

In all cells a gene encodes for

In nature,the predominant form of DNA is supercoiled in a negative direction.

Speculate on why it can be problematic to copy and express genes from Bacteria into Eukarya.

Most prokaryotic genomes are double-stranded circular DNA.

Some essential genes and DNA sequences in cells DO NOT encode for proteins but are still essential for cellular growth and replication.Give two examples of a gene or sequence of which this is true and explain why it is essential for growth or replication.

Microorganisms and Microbiology

Microbial Cell Structure and Function

Microbial Metabolism

Microbial Growth and Control

Microbial Genomics

Metabolic Regulation

Viruses and Virology

Viral Genomes and Diversity

Genetics of Bacteria and Archaea

Genetic Engineering and Biotechnology

Microbial Evolution and Systematics

Metabolic Diversity of Microorganisms

Functional Diversity of Bacteria

Diversity of Bacteria

Diversity of Archaea

Diversity of Eukaryotic Microorganisms

Methods in Microbial Ecology

Microbial Ecosystems

Nutrient Cycles

Microbiology of the Built Environment

Microbial Symbioses

Microbial Interactions With Humans

Immunity and Host Defense

Immune Mechanisms

Molecular Immunology

Diagnostic Microbiology

Epidemiology

Person-To-Person Bacterial and Viral Diseases

Vectorborne and Soilborne Bacterial and Viral Diseases

Water and Food As Vehicles of Bacterial Diseases

Eukaryotic Pathogens: Fungal and Parasitic Diseases

Filters

In several ribosomes can simultaneously translate a single mRNA molecule in a complex called a(n).

The codon on the matches with the anticodon on the to direct the addition of the correct amino acid to the growing polypeptide chain.

DNA replication always proceeds in only one direction because the of the incoming nucleotide is attached to the free of the growing DNA strand.