24: Epigenetic Mechanisms Quizellenj2022-11-23T14:13:22-05:00 Please sign up for the course before taking this quiz. 1. When a gene is being used and being transcribed, we say it is being _______________.1 silenced expressed exposed modified 2. The DNA in the nucleus contains every bit of information that any cell will ever need for the entire lifetime of the organism.1 True False 3. What does methylation do to DNA?1 Keeps the DNA strands closed so they cannot be transcribed. Opens DNA strands to promote DNA transcription. Replicates it. Destroys "junk" DNA. 4. How many histones come together to make the nucleosome?1 4 2 8 12 5. What does “epi-genetics” roughly mean?1 "without/no genes" "outside of the genes" "before genes" "within the genes" 6. What is the “methyl” group?1 CH3-R CH4 CH3 COOH 7. What do nucleosomes/histones help to do?1 Replicate DNA. Keep DNA organized. "Spell check" replicated DNA for errors. Translate proteins. 8. Genes can be made up of many different DNA sections that are spread out and must be spliced together.1 True False 9. MicroRNAs or miRNAs help to regulate gene expression by1 helping DNA polymerase to bind to DNA for gene transcription, therefore "upregulating" the gene. binding to mRNA that shouldn't be translated by a ribosome, therefore blocking the product of the gene. "cutting" up pieces of mRNA into little fragments so that they cannot be translated. binding to DNA polymerase and preventing it from binding to DNA strands, therefore "silencing" the gene. 10. The “switches” on nucleosomes (histone spools) can be activated by all of these molecules EXCEPT:1 Phosphate (PO4) DNA polymerase Methyl (CH3) Acetyl (COCH3) 23: Mitosis (and DNA replication) Final Exam: lessons 1-24 Back to: 24: Epigenetic Mechanisms