MB 8 - Test 3
Several of the different globin genes are expressed in humans but at different times in development. What mechanism could allow for this?
different gene regulation over time
If cells of an individual contain the same set of genes, how do these cells become different from each other during development?
Differences in extracellular signals received by each cell lead to differences in the types of regulatory proteins present in each cell.
Which of these directly bind(s) to the promoter?
C and D
What is alternative splicing?
mRNA processing that leads to different combinations of exons being spliced together
Which of these indicates an enhancer region?
A
You work for a company creating gene therapy treatments. Which of the following chromosomes do you focus on to work on a treatment for BRCA2?
13
Where would RNA polymerase attach?
A (RNA polymerase attaches to DNA)
Why is RNA interference aptly named?
Both the miRNA that does the interfering and the mRNA that is destroyed are RNA.
If you wanted to prevent a regulatory protein from changing gene expression, you would have to prevent physical contact between the protein and _____.
DNA
Why do histones bind tightly to DNA?
Histones are positively charged, and DNA is negatively charged
What level of transcription would you predict for a gene whose promoter is heavily methylated?
Low to no transcription levels
You are a physician. A female patient tests positive for the BRCA2 gene. Which of the following would be best to tell her?
She has in increased risk of getting breast and ovarian cancer and should be monitored as such.
A woman tests positive for the BRCA2 mutation. Which of the following is true?
She inherited the gene from her mother or her father
What is the difference between the core promoter and promoter-proximal regulatory elements?
The core promoter is the site for binding of proteins required for transcribing all genes, such as TATA-binding protein and RNA polymerase, but the promoter-proximal elements are unique to sets of genes that are regulated together.
How do miRNA recognize a particular target mRNA?
The miRNA sequence is complementary to the mRNA sequence so they base pair.
Of the following, which is the most current description of a gene?
a DNA sequence that is expressed to form a functional product: either RNA or polypeptide
In negative control, a gene is switched off when _____.
a regulatory protein binds to DNA and shuts down the transcription
Which of the following statements about the DNA in one of your brain cells is TRUE? a. It is the same as the DNA in one of your heart cells b. All of the genes of the genome are likely to be transcribed c. Each gene lies immediately adjacent to an enhancer d. Most of the DNA codes for protein e. Many related genes are transcribed from a single promoter
a. It is the same as the DNA in one of your heart cells
_____ bind(s) to DNA enhancer regions.
activators
Which of the following statements is the best interpretation of the model? a. If an activator binds to the coding region of the araB gene, then it is transcribed b. If an activator binds to the DNA regulatory sequence, then the araB gene is transcribed c. If an activator binds to the DNA regulatory sequence, then the araB gene is translated d. If an activator binds to the araB gene, then it is is translated
b. If an activator binds to the DNA regulatory sequence, then the araB gene is transcribed
A man tests positive for BRCA2. Which of the following should he be monitored for?
breast and prostate cancer
Which of the following genes is most similar to BRCA2? a. HRAs, an oncogene linked to bladder cancer b. Ras, a proto-oncogene linked to pancreatic cancer c. RB gene, a tumor-suppressing gene linked to retinoblastoma d. CYPZE1, a self-destructive gene.
c. RB gene, a tumor-suppressing gene linked to retinoblastoma
Which method is utilized by eukaryotes to control their gene expression that is NOT used in bacteria?
control of both RNA splicing and chromatin remodeling
Which of the following allows more than one type of protein to be produced from one gene? a. control of the frequency of translation initiation b. alternative forms of nucleosomes c. alternative forms of chromatin remodeling d. alternative forms of RNA splicing
d. alternative forms of RNA splicing
DNA methylation and histone acetylation are examples of _____.
epigenetic phenomena
Muscle cells differ from nerve cells mainly because they _____ _____ ____.
express different genes
The predominant mechanism driving cellular differentiation is the difference in gene _____.
expression
How would decreasing the stability of an mRNA impact the amount of protein encoded by that mRNA?
fewer proteins will be produced by that mRNA
If you were to observe the activity of methylated DNA, you would expect it to _____.
have turned off or slowed down the process of transcription
The greatest expression of the lac operon occurs when lactose levels are _____.
high and glucose levels are low
In a nucleosome, the DNA is wrapped around _____.
histones
Cloning of plants from cuttings demonstrates that ________.
mature plant cells retain the full genetic information needed to carry out the developmental processes to produce a new individual plant
In eukaryotes, the normal or default state is that genes are turned _____.
off through their association in nucleosomes
On what sequence of DNA does the lac repressor bind?
operator of lac operon
Activator proteins in eukaryotes usually have a domain that binds to DNA and other activation domains that often bind to _____.
other regulatory proteins
The product of the lacI gene functions most like a car's _____.
parking break
What is chromatin?
the complex of DNA and proteins found in the nucleus
Cell differentiation always involves ________.
the production of tissue-specific proteins, such as muscle actin
Why are the genes involved in lactose metabolism considered to be an operon?
they are all controlled by the same promoter
Regulation of the lac operon by the CAP protein is an example of gene regulation at what level?
transcription
