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