BIOL-UA 21 Lecture Notes - Lecture 18: Myod, Transcription Factor, Regulatory Sequence
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QUESTION 1
How is a bone marrow transplant able to treat someone with leukemia?
The donor blood contains antibodies that destroy cancer cells | ||
Donor blood contains stem cells that regenerate cells in the immune system | ||
Bone marrow contains induced pluripotent stem cells that turn into red blood cells | ||
Bone marrow contains tumor supressor genes that slow down leukemia growth | ||
Bone marrow contains pluripotent human embryonic stem cells |
1.2 points
QUESTION 2
What would happen if siRNAs designed to target mRNA from an oncogene were introduced into cancer cells?
Increased genomic instability would result from adding foreign nucleic acids | ||
New mutations would arise in the oncogene | ||
The oncogene would be converted back into a proto-oncogene | ||
The siRNAs would compete with the oncogene's active site | ||
Production of the oncogene protein would decrease |
1.2 points
QUESTION 3
What is the purpose of chromatin-remodeling enzymes in human cells?
The enzymes control the rate of translation of an mRNA transcript | ||
The enzymes add phosphate or methyl groups to histone tails | ||
The enzymes slide nucleosomes farther apart or closer to each other | ||
The enzymes send damaged proteins to the proteasome for degradation | ||
The enzymes cause DNA looping to occur |
1.2 points
QUESTION 4
If you wanted to resurrect the mammoth, how would you do it?
Use somatic cell nuclear transfer to insert the mammoth genome into the egg of an elephant | ||
Use transcription factors to re-program adult cells from elephants into mammoth cells | ||
Change the gene expression patterns of elephants to increase production of mammoth genes | ||
Use siRNAs to decrease expression of elephant-specific genes in an elephant embryo |
1.2 points
QUESTION 5
How is eukaryotic transcription initiated?
RNA polymerase is recruited to the start codon by transcription factors | ||
RNA polymerase begins transcription at the enhancer sequence | ||
RNA polymerase is activated by binding to GTP | ||
An initiator tRNA binds to the ribosome | ||
A complex of proteins forms at the promoter of a gene |
QUESTION 10
If you can drink milk as an adult, it means that you have inherited a mutation in the promoter of your lactase gene (the gene that encodes the enzyme you need to break down lactose). Predict the effect of this mutation:
The mutation changes the number of domains in the enzyme, which makes it work more efficiently | ||
The mutation changes the amino acid sequence of the lactase protein | ||
The mutation increases the number of copies of the lactase gene that will be found in your genome | ||
The mutation changes whether the lactase sequence is found in an intron or exon | ||
The mutation affects the expression of the lactase gene |
1.2 points
QUESTION 11
A competitive inhibitor is decreasing the activity of an enzyme. Predict the effect of adding more substrate to the reaction.
The substrate will increase the reaction rate by binding to the allosteric site | ||
The substrate will increase the reaction rate by competing with the inhibitor for the active site | ||
The reaction rate will not change unless the inhibitor can be removed | ||
The enzyme adjusts its shape so that the substrate, but NOT the competitive inhibitor, can bind | ||
The substrate will bind to the competitive inhibitor and block its ability to bind to the enzyme |
1.2 points
QUESTION 12
What determines where in the genome a transcription regulator will bind?
Transcription regulators bind to the 5' UTR region of a gene | ||
Regulators bind via complementary base-pairing to certain DNA molecules | ||
Covalent bonds form between the transcription regulator and the atoms of the DNA backbone | ||
Every eukaryotic gene has a different transcription regulator that will bind to the 5' end of the gene | ||
Transcription regulators bind to specific DNA sequences via multiple weak non-covalent interactions |
1.2 points
QUESTION 13
What is the basic premise of cell theory?
DNA -> RNA -> protein | ||
All cells arise from pre-existing cells | ||
DNA provides the complete instructions to create a cell | ||
The identity of a cell is determined through gene expression patterns | ||
All cells contain the same four basic macromolecules |
1.2 points
QUESTION 14
What is the benefit of using BOTH the lac activator and the lac repressor to control gene expression?
Using both an activator and repressor enables cells to more accurately determine the amount of lactose available in the environment | ||
Enzymes to digest lactose are only made when energy is low and lactose is available | ||
The activator can override the inhibition of the lac operon by the repressor | ||
The repressor can control the enhancer, while the activator can control the promoter | ||
When neither the lac activator or repressor is present, expression of the lac operon is too high |
1.2 points
QUESTION 15
What is the histone code used for?
Phosphorylation and acetylation of DNA affect its ability to be compacted | ||
Changes to the sequence of DNA change whether DNA will wrap around histone proteins | ||
Covalent modifications of histones affect the ability of the transcription initiation complex to form | ||
Histones provide the codon sequences needed for translation to occur | ||
The histone code affects which amino acids will get added to a polypeptide |