24: Epigenetic Mechanisms Quizellenjmchenry2022-11-23T14:13:22-05:00 Please sign up for the course before taking this quiz. Genes can be made up of many different DNA sections that are spread out and must be spliced together.1 True False When a gene is being used and being transcribed, we say it is being _______________.1 expressed modified exposed silenced What do nucleosomes/histones help to do?1 Replicate DNA. Translate proteins. "Spell check" replicated DNA for errors. Keep DNA organized. How many histones come together to make the nucleosome?1 4 2 12 8 What is the “methyl” group?1 CH4 COOH CH3-R CH3 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 What does methylation do to DNA?1 Opens DNA strands to promote DNA transcription. Keeps the DNA strands closed so they cannot be transcribed. Replicates it. Destroys "junk" DNA. What does “epi-genetics” roughly mean?1 "without/no genes" "outside of the genes" "within the genes" "before genes" 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. "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. helping DNA polymerase to bind to DNA for gene transcription, therefore "upregulating" the gene. The “switches” on nucleosomes (histone spools) can be activated by all of these molecules EXCEPT:1 Acetyl (COCH3) DNA polymerase Methyl (CH3) Phosphate (PO4) 23: Mitosis (and DNA replication) Final Exam: lessons 1-24 Back to: 24: Epigenetic Mechanisms