Questions vocab Flashcards
DNA methylation
Epigenetic phenomenon
Cell differentiation
a process in which cells become specialized.
Histone proteins
A histone is a positively charged protein that provides structural support for a chromosome. Each chromosome contains a long molecule of DNA, which must fit into the cell nucleus. To do that, the DNA wraps around complexes of histone proteins, giving the chromosome a more compact shape.
The positively charged histones interact with the negatively charged phosphate groups of DNA, forming strong electrostatic bonds.
Histone acetyltransferases
zz
Enhancer
silencer-binding transcription factor
an enhancer-binding transcription factor
Promoter-proximal-binding transcription factor
the TATA-binding protein
MicroRNAs
Regulatory transcription factors ________.
Influence specific expression of gene
Alternative splicing
mRNA processing that leads to different combinations of exons being spliced together
RNA interference
It either destroys mRNA
or blocks its translation.
Which of the following is most likely to have a small protein called ubiquitin attached to it?
a cyclin protein, which usually acts in G1, in a cell that is in G2
The phenomenon in which RNA molecules in a cell are destroyed if they have a sequence complementary to an introduced double-stranded RNA is called _____.
RNA itnerference
MicroRNAs control gene expression at the level of _______.
translation
These prevent transcribed mRNA from being made into proteins. Either the mRNAs are cut and degraded, or they are blocked from interacting with ribosomes.
Predict what would happen to regulation of the lac operon if the lacI gene were moved 50,000 nucleotides upstream of its normal location.
Regulation of the lac operon should be normal.
Which of the following statements is about regulation of the lac operon?
A mutation that alters the catabolite activator protein is predicted to alter the regulation of many different operons.
There is a mutation in the repressor that results in a molecule known as a super-repressor because it represses the lac operon permanently. Which of these would characterize such a mutant?
It cannot bind to the inducer.
Which of the following would be true in an E. coli cell when glucose concentrations outside the cell are high?
CAP would be transcribed.
In lac mutant cells, when there are high levels of glucose present but no lactose, how much -galactosidase will be produced?
A great deal
Which choice is utilized by eukaryotes to control their gene expression that is NOT used in bacteria?
Control of both RNA splicing and chromatin remodeling
A gene-regulation strategy that is unique to eukaryotic cells is __________.
mRNA processing
Which statements about chromatin condensation are incorrect?
An inhibitor of histone deacetylase would promote chromatin condensation.
Chromatin remodeling complexes add chemical groups to histones.
Why do histones bind tightly to DNA?
Histones are positively charged, and DNA is negatively charged.
In eukaryotes, what allows only certain genes to be expressed in different types of cells?
Different sets of regulatory transcription factors present in each cell
How do chromatin-remodeling complexes recognize the genes they should act on? Chromatin-remodeling complexes _____.
recognize specific transcription factors bound to regulatory sequences of DNA
