24: Epigenetic Mechanisms Quizellenjmchenry2021-10-01T23:30:12-04:00 Please sign up for the course before taking this quiz. The “switches” on nucleosomes (histone spools) can be activated by all of these molecules EXCEPT:1 Acetyl (COCH3) Methyl (CH3) Phosphate (PO4) DNA polymerase What is the “methyl” group?1 COOH CH3 CH3-R CH4 What do nucleosomes/histones help to do?1 Replicate DNA. Translate proteins. "Spell check" replicated DNA for errors. Keep DNA organized. What does “epi-genetics” roughly mean?1 "without/no genes" "within the genes" "before genes" "outside of the genes" How many histones come together to make the nucleosome?1 12 2 8 4 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. 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. helping DNA polymerase to bind to DNA for gene transcription, therefore "upregulating" 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. When a gene is being used and being transcribed, we say it is being _______________.1 exposed expressed silenced modified 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 Genes can be made up of many different DNA sections that are spread out and must be spliced together.1 True False 23: Mitosis (and DNA replication) Final Exam: lessons 1-24 Back to: 24: Epigenetic Mechanisms
