Which of the following are true about miRNA? (select all that apply) They form a hairpin structure after transcription They are cleaved in the nucleus and in the cytoplasm Each miRNA has only one target gene to regulate Each miRNA can only be used once by the RISC complex before it is degraded It is a mechanism that can allow coordinated silencing of a group of mRNA They likely evolved from the siRNA viral defense mechanism It is a type of CRISPR.