Pick 4 from the following list and write one brief paragraph about each of your
ID: 3164967 • Letter: P
Question
Pick 4 from the following list and write one brief paragraph about each of your choices (2.5 pts each): what's the purpose of a complementation test? -distinguish DNA synthesis enzymes from translation enzymes -how can you tell sense from antisense DNA; what are some common motifs that appear on a sense strand? -why does the lagging strand lag? -what's different between gDNA and gRNA? -why don't prokaryotes use RNAi? -where does AUG go and what guides it there? -why not use RNA for storing genetic information? Viruses do -in the 1970s, introns were considered junk DNA whose only purpose was to keep gene regions separated; what do researchers now think its function is? -how could you cure a protein-folding disorder?Explanation / Answer
1. What is the purpose of complemetation test?
Complementation tests or Cis-trans test was developed by Edward Lewis and is used to check whether mutations in two strains occur in different genes. Complementation will not occur if the mutations are in the same gene.
2. How can you tell sense from anti-sense DNA;What are some common motifs that occur on a sense strand?
The sense strand or the coding strand runs in the 5' to 3' direction and is the same sequence as the mRNA. The anti-sense strand or the template strand runs in the 3' to 5' direction and translates the RNA into protein. The sense strand and anti-sense strands are complimentary to each other. Common motifs that occur on a sense strand are specific for genus and segment and are Helix-Turn-Helix and Zinc -finger motif
3 Why does the lagging strand lag?
The lagging strand needs to be replicated in the opposite direction of replication fork and are thus short fragments are formed which are called Okazaki fragments which are incomplete, short segments of DNA since the replication occurring is discontinuous.
Why not use RNA for storing information? Viruses do
DNA is more stable than RNA and hence is used to store genetic information. The genetic material needs to be passed on through generations and needs to be stable. Also RNA contains uracil while DNA contains thymine which has methylated group which helps in DNA repair which is seen as an advantage over RNA by protecting the integrity of the genetic sequence.