Substances can move into and out of cells through the cell membrane. The three main types of movement are diffusion, osmosis and active transport. 1  1. 2  2. 3  3. 4  4.
Definition. noun. Abbreviated form for messenger ribonucleic acid, the type of RNA that codes for the chemical blueprint for a protein (during protein synthesis). Supplement. In prokaryotes, mRNA is produced by splicing a large primary transcript from a DNA sequence.
Precursor mRNA (pre-mRNA) is an immature single strand of messenger ribonucleic acid (mRNA).Pre-mRNA is synthesized from a DNA template in the cell nucleus by transcription. Pre-mRNA comprises the bulk of heterogeneous nuclear RNA (hnRNA).The term hnRNA is often used as a synonym for pre-mRNA, although, in the strict sense, hnRNA may include nuclear RNA transcripts that do not end up as cytoplasmic mRNA.re-mRNA is synthesized from a DNA template in the cell nucleus by transcription. Pre-mRNA comprises the bulk of heterogeneous nuclear RNA (hnRNA). The term hnRNA is often used as a synonym for pre-mRNA, although, in the strict sense, hnRNA may include nuclear RNA transcripts that do not end up as cytoplasmic mRNA.