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.
Man-made polymers include plastics like the one composing these water bottles. If you've ever made a long paper chain, you already have a visual image of a polymer. The term comes from the Greek words poly, meaning many, and meros, meaning part.. Combine the two and you get many parts.. The simplest definition of a polymer is long chain formed by joining many smaller molecules, called monomers [source: Larsen]. While a paper chain presents a simple image of a polymer, in practical applications, polymers have much greater uses.