Genes Flashcards
What is DNA methylation?
The adding of a methyl group or CH3 to a nucleotide.
What is epigenetics in simple terms?
Modification of expression of genes.
What are exonucleases?
The groups that remove nucleotides one by one from an mRNA.
What do Deadenylation complexes do?
They remove the poly - A tail from the mRNA.
What are promoter regions?
Base sequence where RNA polymerase binds to begin transcription
What are transcription factors?
DNA binding protein that controls transcription by binding to an enhancer or a silencer.
What are enhancers?
base sequence that promotes transcription when a transcription factor binds there.
What is a silencer?
base sequence that blocks transcription when a transcription factor binds there.
Which of the following is directly involved in controlling gene expression?
I. DNA replication
II. RNA splicing
III. mRNA degradation
IV. Histone modification
II, III and IV only
What is the impact of epigenetic changes on gene expression?
A. To alter the DNA base sequence thus affecting genotype
B. To change the phenotype without altering the genotype
C. To prevent translation of proteins
D. To silence genes permanently
B
In order from smallest to biggest, which is correct?
A. Proteome, transcriptome, genome
B. Genome, proteome, transcriptome
C. Genome, transcriptome, proteome
D. Transcriptome, genome, proteome
C
Which statement is true regarding the lac operon?
A. It shows an example of allosteric inhibition of an enzyme
B. It regulates the expression of genes involved in lactose metabolism
C. It shows an example of hormone regulation of gene expression
D. It functions as a transcription factor for gene activation
B
How do transcription factors regulate gene expression?
A. By interacting with DNA polymerase
B. By binding to activator sequences and increasing the rate of transcription
C. By mediating binding of RNA polymerase to the promoter
D. By binding to repressor sequences and decreasing the rate of transcription
C
What happens if a mitochondria is not present in the daughter cell?
The cell is not able to produce replacement Mitochondria.
What are the two examples of unequal division in cells?
- Budding in yeast - form of sexual reproduction where a small daughter cell buds off a larger cell by cytokinesis.
- Oogenesis - formation of eggs in females, involves unequal division of cells during meiosis to produce one large egg cell.
What are cells produced without a nucleus called?
Anucleate
How are sister chromatids held together?
By a center centromere
When are sister chromatids separated?
During Anaphase of mitosis and Anaphase II of Meiosis.
What are mutagens?
The agents that cause permanent heritable changes to the DNA of cells.
Examples include gamma rays, UV light, and x-rays.
Which nitrogen base has the highest probability of mutation?
Cytosine
What are somatic cells?
Cells that are not passed on and not used for reproduction.
What do mutations to proto-oncogenes in somatic cells result in?
Uncontrolled cell division / cancer.
What is gene knockout?
A technique where a targeted gene is inactivated or removed from an organism.
What are the uses of CRISPR and cas-9?
- Gene-therapy : used to replace of repair a gene that is responsible for genetic diseases.
- Genetic Research : method to knock out genes, allowing researchers to better understand the action of specific genes.
- Malaria prevention : can be used to modify the genomes of mosquitoes which could reduce the spread of Malaria.
