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1. In animals, most microRNAs come from__________ transcription in the nucleus t

ID: 55909 • Letter: 1

Question

1. In animals, most microRNAs come from__________

transcription in the nucleus

the extracellular environment

viral infections

RNA synthesis occurring in the RNA induced silencing complex

2. How does RNA interference affect gene expression?

Sequence-specific double-stranded RNAs induce activation of homologous genes

Sequence-specific double-stranded RNAs induce silencing of homologous genes

Sequence-specific double-stranded RNAs induce silencing of non homologous genes

Sequence-specific double-stranded RNAs induce activation of non homologous genes

3. S. pombe uses RNA induced transcriptional silencing_________

to block translation of target mRNAs.

to remove methyl groups from H3K9.

as a defense mechanism against viruses.

to close chromatin in the centromere.

4. Which of the following is not an epigenetic mark?

Histone methylation

Histone acetylation

DNA methylation

DNA acetylation

Histone phosphorylation

a.

transcription in the nucleus

b.

the extracellular environment

c.

viral infections

d.

RNA synthesis occurring in the RNA induced silencing complex

Explanation / Answer

1.

a. Transcription in the nucleus

MiRNA found that instead of producing an mRNA encoding a protein, it produced short noncoding RNAs,

The mature miRNA is part of an active RNA-induced silencing complex (RISC) containing Dicer and many associated proteins.

2.

b. Sequence-specific double-stranded RNAs induce silencing of homologous genes

3.

d. to close chromatin in the centromere.

4.

d. DNA acetylation