In: Biology
1) Cis acting regions: DNA sequences usually 100-1000bp in the vicinity of the structural portion of a gene to which transcriptional factor proteins binds which are required for gene expression.
They are labeled as cis because they are typically located on the same DNA strand as the genes they control as opposed to trans, which refers to effects on genes not located on the same strand or farther away, such as transcription factors (RNA ploymerase)
Cis-regulatory modules typically divided into three classes namely enhancers ( regulate gene expression positively) insulators ( works indirectly by interacting with other nearby cis-regulatory regions) and silencers (turn off expression of genes)
Answer 2)
a) Much of the complexity of eukaryotic genomes results from the abundance of several different types of noncoding sequences.
b) Presence of complex and not well understand promoter and other gene regulatory elements
C) Presence of complex splicing mechansim for removal of Introns
Answer 3)Gene Annotation is the process by which information about raw DNA sequences is added to the genome databases. This involves describing different regions of the code and identifying which regions can be called genes.