Unit 2 Genetics
In simple transposition __________________
a double-stranded piece of DNA is moved from one site to another.
When an F factor integrates into the chromosome, it creates
a high frequency of recombination (Hfr) cell.
An advantage of negative supercoiling in bacteria is that
it promotes strand separation in small regions enhancing DNA replication and transcription.
The two strands of DNA are antiparallel, meaning that
the two strands have opposite orientation of their 5′ and 3′ ends.
During _____, a portion of a bacterial chromosome is transferred to a recipient cell via a _____.
transduction; bacteriophage
During reproduction, there is ____________ of the genetic material from parents to offspring.
transmission
Genetic material must have ___________ that can account for phenotypic differences within each species.
variation
Which bacterial genetic transfer process does NOT require recombination with the bacterial chromosome?
F+ x F- conjugation
Because they contain nucleic acid and reproduce, most virologists consider viruses as living organisms. T/F
False
Centromeres contain specialized sequences located at both ends of the linear chromosome
False
Eukaryotic chromosomes contain a telomere that forms a recognition site for the kinetochore proteins. T/F
False
All viruses use DNA as their genetic material. T/F
False-some use RNA
A typical eukaryotic chromosome is about one hundred thousand base pairs in length. T/F
False. has tens of millions-hundreds of millions bp in length
Eukaryotic chromosomes are usually circular. T/F
False.contains a linear DNA molcule
Natural transformation
A natural process that has evolved in certain bacteria in which they can take up extracellular DNA
Highly repetitive sequences
-Alu -Centromeric tandem arrays
Unique sequences
-structural genes -exons which encode polypeptides -intron sequences
What is the product of DNA replication
2 daughter DNA molecules
What would have been the result of the Hershey Chase experiment if proteins, rather than DNA, were the genetic material?
35S would have been found inside the bacterial cells.
An inverted repeat on an insertion element has the sequence 5'-AGTCAT-3'. What will be the sequence of the inverted repeat at the end of the insertion element on the same strand?
5'-ATGACT-3'
fertility plasmid
Allow bacteria to mate/conjugate with each other
Artificial transformation
An unnatural process in which the bacterial cells are forced to take up DNA
Which form of DNA is the predominant form found in living cells?
B DNA
Competence factors
Bacteria that can take up DNA naturally carry genes that encode these type of proteins
Competent cells
Bacterial cells that are able to take up DNA
Virulence plasmids
Carries genes that turn a bacterium into a pathogenic strain
Resistance plasmids
Contain genes that confer resistance against antibiotics and other types of toxins
Col-plasmids
Contain genes that encode colicins, which are proteins that kill other bacteria
What part of the T2 phage enters the bacterial cell following infection? Multiple Choice
DNA
Hershey and Chase
Determined that the genetic material of T2 phage is DNA. -used radioisotopes to distinguish proteins from DNA
Avery, MacLeod, and McCarty
Discovered that DNA is the substance that transforms bacteria.
Components of DNA molecules
Nitrogenous base, phosphate group, deoxyribose
Weismann and Nägeli
Proposed that a chemical substance within living cells is responsible for the transmission of traits from parents to offspring.
Griffith
Showed that the genetic material from type S bacteria could transform type R bacteria into type S.
Nonhomologous recombination
The process by which DNA that is not similar to a region of DNA in the bacterial chromosome is incorporated into the bacterial chromosome
Homologous recombination
The process by which DNA that is similar to a region of DNA in the bacterial chromosome is incorporated into the bacterial chromosome
The process of forming RNA from a template strand of DNA is called__________
Transcription
A typical eukaryotic chromosome contains between a few hundred and several thousand different genes. T/F
True
Eukaryotic chromosomes contain many origins of replication that are interspersed about every 100,000 base pairs. T/F
True
In horizontal gene transfer, DNA can be acquired from the same species or from a different species. T/F
True
In simple transposition, the transposable element ends up between two direct repeats of the target sequence. T/F
True
Many eukaryotic species are diploid with two sets of chromosomes in somatic cells. T/F
True
Phage T2 infection of a bacterial cell is accompanied by degradation of host cell DNA. T/F
True
The term phage is an abbreviation of the word bacteriophage. T/F
True
Mature T2 phage particles are released
after lysis of the bacterial host cell.
The protein coat that surrounds the genetic material of the T2 phage is termed the
capsid
Degradative plasmids
carry genes that enable the bacterium to digest and utilize an unusual substance
Which form of bacterial gene transfer requires direct contact between two cells?
conjugation
Simple transposition is also called ________ transposition.
conservative
The genetic material must contain the __________ necessary to construct an entire organism.
information
Moderately repetitive sequences
rRNA genes
The__________of genetic material allows it to be passed from parents to offspring, and from a mother cell to daughter cells.
replication