Microbiology Chapter 8

A codon contains how many nucleotides?

3

gel electrophoresis separates DNA fragments using

electric current

What is a mutation?

A permanent inheritable alteration in the DNA sequence or content of a cell.

Which describes a plamsid?

A small circular piece of DNA that replicates its nonessential genes independently of the chromosome

Which of the following statements regarding conjugation is true?

After conjugation, the recipient cell will be F+

Which of the following are attributes of bacterial chromosomes?

Cells usually have one to three chromosomes. Circular DNA molecule

Genomes of cells are composed of... protein DNA RNA

DNA

What is the central theme of molecular biology?

DNA encodes RNA which encodes protein

Cellular genomes are composed of... DNA or RNA RNA only DNA only

DNA only

Removes the primer. closes gaps, and repairs mismatches

DNA polymerase 1

Adds bases the the growing DNA chain, proofreads

DNA polymerase 111

A(n) ____ cell has a separate fertility plasmid, whereas a(n) _____ cell has the F factor incorporated into its chromosome

F+; Hfr

True or False: Eukaryotic chromosomes are composed of DNA and RNA.

False

Transfer of DNA from a source other than the parent organisms

Horizontal gene transfer

Select all that apply Which of the following are attributes of eukaryotic chromosomes? Their DNA is tightly wound around histone proteins. They are linear, composed of double-stranded DNA. They are located in a cytoplasmic region called the nucleoid. The number of chromosomes in a eukaryotic cell can vary from a few to hundreds.

Their DNA is tightly wound around histone proteins. They are linear, composed of double-stranded DNA. The number of chromosomes in a eukaryotic cell can vary from a few to hundreds.

True or False: Only viruses can have an RNA genome.

True

True or false: The structure of DNA is essential for providing variety since the order of nucleotides is responsible for the unique qualities of each organism.

True

Transfer of DNA from parent organisms during reproduction

Vertical gene transfer

A single nucleotide polymorphism results from

a change in one base in a gene

Conjugation is a conservative process, meaning that....

a copy of the DNA being transferred is retained by the donor.

Which type of mutation has occurred when a gene that has undergone mutation reverses back to its original sequence

back mutation

The genes of which microorganism(s) are arranged as operons?

bacteria

Restriction endonucleases are enzymes which cut DNA at a specific palindromic sequence. They are produced

by bacteria to protect against viral infection

A _____ is a discrete cellular structure composed of an elongated DNA molecule.

chromosome

A discrete cellular structure composed of a neatly packaged DNA molecule is called a(n)

chromosome

Select all that apply Which of the following are attributes of bacterial chromosomes? circular DNA molecule enclosed in a membrane-bound organelle cells usually have one to three chromosomes organized by histone proteins

circular DNA molecule cells usually have one to three chromosomes

DNA that is made from RNA is called

complementary DNA

In bacteria, horizontal gene transmission through a pilus is called

conjugation

Three methods of gene transfer in bacteria

conjugation transformation transduction

____ involves the use of a connection bridge, _____ requires a bacterial virus vector, and _____ entails transfer of naked DNA

conjugation; transduction; transformation

Synthetic biology may be used to

create an operon using genes from different microbes create a cell whose entire chromosome was synthesized in vitro create an antibody with defined specificty

In the bacterium Escherichia coli, where is the chromosome located? plasmid cytoplasm nucleus

cytoplasm

What are the three components of a DNA nucleotide?

deoxyribose sugar phosphate nitrogenous base

In DNA, each nucleotide is composed of a sugar called ____, a nitrogenous _____, and a _____ group.

deoxyribose, base, phosphate

DNA replication involves all of these steps EXCEPT unzipping hydrogen bonds between complementary base pairs dissolution of the nuclear membrane synthesizing new DNA matching complementary base pairs uncoiling parent DNA

dissolution of the nuclear membrane

Ensuring that the DNA code is maintained during DNA replication and cell _____ is one of the essential effects of DNA structure.

division

Which is true regarding DNA semiconservative replication?

each new DNA helix contains one parent strand and one newly synthesized strand

True or false: DNA strands are parallel, running in the same orientation

false

Which type of mutation is generally most harmful to cells?

frameshift mutation

A faulty disease-causing gene is replaced with a gene from a healthy organism in the process called

gene therapy

The science of heredity is... biology reproduction genetics

genetics

The ____ is the sum total of genetic material in an organism. chromosome proteome gene genome

genome

Which term represents all of the genetic information within a cell? chromosome genome gene

genome

Unzips the DNA helix

helicase

How does RNA differ from DNA

in RNA, uracil replaces thymine. RNA is usually single-stranded.

Where are chromosomes of yeast cells located? in the nucleus on the rough ER free in the cytoplasm

in the nucleus

Which type of mutation results from exposure to a mutagen?

induced mutation

A sequence of DNA in a eukaryotic gene that does not code for protein is called a(n)

intron

eukaryotic mRNA contain non-coding regions called

introns

Seals nicks in DNA

ligase

A change in the genetic code that leads to the insertion of a different amino acid in a protein is called a

missense mutation

Eukaryotic chromosomes are located in/on the ____ of the cell endoplasmic reticulum cytoplasm nucleoid nucleus

nucleus

Eukaryotic chromosomes are located in the ____, while prokaryotic chromosomes are found in the _____.

nucleus; nucleoid

Which unit in bacteria consists of a regulatory gene, a control region, and structural genes?

operon

Bacterial and archaeal genes are arranged into

operons

Phase variation is a type of _____ variation

phenotypic

Donor and recipient bacterial cells are connected by the sex _____ during conjugation.

pilus

The process occurring in this image is the

polymerase chain reaction

Synthesizes an RNA primer

primase

The type of macromolecule that is formed from long chains of amino acids produced in translation is a(n)

protein carbohydrate lipid polypeptide transcription

An event in which one bacterium donates DNA to another bacterium, resulting in a strain that differs from both donor and recipient, is a type of genetic transfer called

recombination

During ______, the DNA is duplicated prior to binary fission.

replication

The process of duplicating is called DNA _____ replication transcription translation

replication

A mutation that alters the DNA sequence of a gene, but does not change the amino acid sequence of the protein that is encoded by the gene is called a(n)

silent mutation

Creating new biological molecules and organisms from scratch is in the realm of

synthetic biology

All of the following are true regarding eukaryotic chromosomes EXCEPT

the chromosomes are located in the nucleoid

The lactose operon itself has three important features. Which of the following is NOT one of these features? the regulator the control locus the inducer the structural locus

the inducer

Untangles newly replicated strands

topoisomerase

Which two types of horizontal gene transfer do NOT require direct contact between the donor and the recipient cells?

transduction and transformation

synthesizing amino acid sequences from messenger RNA is called

translation

Which group of microbes has representatives with either an RNA or DNA genome? bacteria fungi helminths viruses

viruses

The native or _____ type strain exhibits nonmutated characteristics.

wild type