Introduction. The Urinary System is a group of organs in the body concerned with filtering out excess fluid and other substances from the bloodstream. The substances are filtered out from the body in the form of urine. Urine is a liquid produced by the kidneys, collected in the bladder and excreted through the urethra.ntroduction. The Urinary System is a group of organs in the body concerned with filtering out excess fluid and other substances from the bloodstream. The substances are filtered out from the body in the form of urine. Urine is a liquid produced by the kidneys, collected in the bladder and excreted through the urethra.
Concept 2: Transcription and Translation in Cells In a prokaryotic cell, transcription and translation are coupled; that is, translation begins while the mRNA is still being synthesized. In a eukaryotic cell, transcription occurs in the nucleus, and translation occurs in the cytoplasm.
In eukaryotic cells, transcription factors are needed for transcription to occur and there are different types of RNA polymerase molecules that transcribe the DNA depending on the type of genes. Genes that code for proteins are transcribed by RNA polymerase II, genes coding for ribosomal RNAs are transcribed by RNA polymerase I, and genes that code for transfer RNAs are transcribed by RNA polymerase III.