Biology 2581B Lecture Notes - Lecture 15: Noncoding Dna, Euglena, Ribosomal Rna

• School: Western University
• Department: Biology
• Course: Biology 2581B
• Professor: David R Smith

Document Summary

Another example of nuclear chromosome is the large subunit (lsu) and small subunit (ssu) rrna genes intact, and tandemly repeated (head to tail head to tail head to tail). 400 times on five different chromosomes: this is good for when mass producing the ribosomes in one go and exists in humans. These have linear nuclear chromosomes, but the genes are ordered into polycistronic units (meaning that they are transcribed into long chains of genes; up to 100 genes). Then there are chromosomes (mini-circles?) with monocistronic genes which encode 5" caps: the 5" caps then attack the polycistronic transcript by trans- splicing to break the polycistronic transcript into individual gene units/mature mrna. It has a macronucleus (mac) and micronucleus (mic) where. Mac takes up more of the cell: mac is the soma and the active nucleus which gives rise to all the genes and proteins necessary for functioning.