Question

Both plants and animals produce hundreds of tiny RNAs that are relatively small in size (roughly 20-25 nucleotides in length). First discovered in nematodes, they are synthesized only at certain times during development or in certain tissues of a plant or animal, and are presumed to play a regulatory role. They are called _________.

a.TinRNAs
b. sRNAs
c. MicroRNAs
d. b and c

Answer 1

The small RNA molecules described, which are synthesized at certain times and play a regulatory role, are called microRNAs or miRNAs.

Step-by-step explanation:

Both plants and animals produce hundreds of tiny RNAs that are relatively small in size, roughly 20-25 nucleotides in length, which play a regulatory role. These are synthesized only at certain times during development or in certain tissues and were first discovered in nematodes. The correct term for these regulatory RNA molecules is microRNAs (miRNAs).

miRNAs are transcribed from genes that are found across eukaryotes. They start as longer pre-miRNAs in the nucleus and are processed into mature miRNAs by a protein called Dicer. These mature miRNAs then work in conjunction with the RNA-induced silencing complex (RISC) to regulate gene expression by degrading target mRNA molecules.