microRNAs (miRNAs) are small noncoding RNAs that play important roles in posttranscriptional gene regulation. In animal cells, miRNAs regulate their targets by translational inhibition and mRNA destabilization. Here, we review recent work in animal models that provide insight into the diverse roles of miRNAs in vivo.icroRNAs (miRNAs) are small noncoding RNAs that play important roles in posttranscriptional gene regulation. In animal cells, miRNAs regulate their targets by translational inhibition and mRNA destabilization. Here, we review recent work in animal models that provide insight into the diverse roles of miRNAs in vivo.
Polymer Definition. A polymer is a large molecule made up of chains or rings of linked monomer units. Polymers usually have high melting and boiling points. Examples: PVC (poly vinyl chloride), polystyrene, cellulose.olymer Definition. A polymer is a large molecule made up of chains or rings of linked monomer units. Polymers usually have high melting and boiling points. Examples: PVC (poly vinyl chloride), polystyrene, cellulose.
Like all plastics, acrylic plastics are polymers. The word polymer comes from the Greek words poly, meaning many, and meros, meaning a part. A polymer, therefore, is a material made up of many molecules, or parts, linked together like a chain. Polymers may have hundreds, or even thousands, of molecules linked together.