Brooker Genetics, Chapters 9-10, 16-21, 24
Which correctly describes F factors?
"F factor" is short for "fertility factor". If present, that cell can act as a donor. After it is transferred by conjugation, the recipient cell becomes F+.
transformation in bacteria
......type of bacterial recombination (create genetic diversity) in which bacteria take up DNA from their environment. These DNA remnants most commonly come from dead bacterial cells. During transformation, the bacterium binds the DNA and transports it across the bacterial cell membrane. The new DNA is then incorporated into the bacterial cell's DNA.
episome
A genetic element that can replicate independently of the chromosomal DNA but also can integrate into chromosomal DNA
operon
A group of two or more genes under the transcriptional control of a single promoter.
natural transformation
A natural process that has evolved in certain bacteria in which they can take up extracellular DNA
virulent phage
A phage that reproduces only by a lytic cycle.
operator
A sequence of bases that provides a binding site for a repressor protein
promoter
A sequence of bases that signals the beginning of transcription.
inducer
A small effector molecule that causes transcription to increase.
competence factor
A species-specific secreted bacterial protein that induces competence for transformation
host cell DNA
A transducing phage contains ___
lytic cycle
A type of viral (phage) replication cycle resulting in the release of new phages by lysis (and death) of the host cell.
epigenetic inheritance
An epigenetic change that is passed from parent to offspring is said to show ____
artificial transformation
An unnatural process in which the bacterial cells are forced to take up DNA
1, 2, 3
Arrange the following in the proper order in which they occur during glucocorticoid hormone action. 1. Binding of hormone to receptor 2. Release of HSP90 proteins 3. Entry of hormone into the nucleus
Transcription, Translation, Posttranslation
Arrange the steps of the regulation of gene expression in bacteria into the correct sequence.
Conjugation in bacteria
Bacterial cells can join together and pass plasmid DNA from one bacterial cell to another. This process can take place between bacteria of different species and is of concern in terms of passing plasmid-located genes for antibiotic resistance.
Transduction in bacteria
DNA is transferred from a donor cell to a recipient via a bacteriophage
Degradative plasmids
Enable the bacterium to digest and utilize an unusual substance
can be a part of
Environmental epigenetic changes occur as the result of environmental factors and ____________ normal development.
histone acetyltransferase
Enzymes which acetylate the positively charged lysines within the core histone proteins.
is part of
Epigenetic changes that occur during development occur in some cells and the pattern of modification ____ development.
reversible
Epigenetics refers to the phenomenon where traits can be inherited through ______ changes in DNA.
F' factors
F factors that carry portions of the bacterial chromosome are called
steroid; endocrine
Glucocorticoids are ________ hormones secreted by ________ glands.
binds to an intracellular receptor to form a complex that then acts as a transcription factor
How does a steroid hormone exert its effect upon a cell?
heritable
In DNA replication, the methylation pattern is ____
(RNA) splicing
In eukaryotes mRNAs are frequently processed by capping, polyA addition, and
cytosine
In eukaryotes, methyl groups are added to the ___ residues
attach specifically to host cell receptors
In regard to virus entry into a cell, viral spikes______
introns, exons
In splicing ___ are removed and ___ ligated together to help create a mature mRNA.
inhibition
Methylation usually results in the ___ on transcription
exo- and endonucleases
RNA degradation occurs by the activity of ____
post-transcriptional but pre-translational level.
RNA interference is a mechanism for silencing gene expression at the
Why do yeast genes with a single intron have essentially no alternative splicing?
Removal of a single intron only leads to one possible outcome for spliced mRNA.
DNA methyltransferase
The enzymes that add the methyl groups are known as
lacO
The lac repressor binds to what site within the lac operon?
chromatin remodeling, methylation, histone modification
The molecular mechanisms that underlie epigenetics include ____, DNA ___, covalent____, localization of histone variants, and feedback loop.
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
Dicer
The protein ________ acts as an endonuclease in the first step of RNA interference.
housekeeping
The residues that precede the ___ genes are typically not methylated.
prophage
Viral DNA integrated in a bacterium
provirus
Viral DNA integrated in a eukaryotic cell
lysine
Which amino acid(s) are acetylated in histones?
Glycosylation
Which of the following is not a common post-translational modification that occurs to histones?
Removal of a single intron leads to splicing of the poly-A tail which prevents further splicing.
Why do yeast genes with a single intron have essentially no alternative splicing?
to prevent degradation of DNA by exonucleases
Why is it important to restore displaced histones to the DNA following transcription?
temperate phage
a phage that is capable of replicating by either a lytic or lysogenic cycle
lac repressor
a protein that binds to the operator site of the lac operon and inhibits transcription
repressor
a regulatory protein that binds to an operator (DNA) and blocks transcription
activator
a regulatory protein that increases the rate of transcription
Allosteric regulation is accomplished by
a small molecule that fits into a site on the enzyme that is not the active site.
Fertility plasmids (F factors)
allow bacteria to share genes by proximity/mate
AU-rich-elements
are found in many short-lived mRNAs
methyl-CpG-binding proteins
bind methylated sequences
Competent cells are cells that
can take up DNA from their surrounding environment and integrate it into their own chromosomes by recombination.
Virulence plasmids
carry genes that cause disease
combinatorial control
combination of many factors determines the expression of any given gene
Resistance plasmids (R plasmids)
confer resistance to antibiotics or other growth inhibitors
When glucose is present (lac operon)
cyclic AMP is low, CAP does not bind to the activator binding site, and transcription is turned off
Col plasmids
encode colicins that can kill neighboring bacteria
one
how many promoters are in an operon?
polyA tail, 3'
mRNA stability can be controlled by the length of the ____ and sequences in the ___ untranslated region
increased
mRNA stability is ____ when the polyA tail is longer
de novo methylation
methylation of DNA that was previously unmethylated
Lysogeny
phage remains latent
DNA methyltransferase
the enzyme that attaches methyl groups to the number 5 position of adenine or cytosine bases
very different
the half lives of mRNAs that code for different proteins are _______
histone code hypothesis
the hypothesis that the pattern of histone modification acts much like a language or code in specifying alterations in chromatin structure.
feedback inhibition
the inhibition of the first enzyme in the pathway by the final product of the pathway.
maintenance methylation
the methylation of hemimethylated DNA following DNA replication by DNA methyltransferase, making it fully methylated
maintenance methylation
the most common form of methylation is ____
One definition of epigenetics would be
the study of reversible mechanisms that lead to changes in gene expression that do not involve changes in DNA sequence.
Horizontal gene transfer can include
when a gene is acquired from another species., conjugation, transduction, transformation
