Module Exam #2

Last update by harmon.271 on 06/08/2011
49434 People have viewed this Quiz
  • Share

What three general characteristics must the genetical material possess?

Answer:
1) Must contain complex information; instructions for all the traits and functions of an organism
2) Must replicate faithfully
3) Must encode the phenotype

View Module Exam #2 as Flashcard Deck

Related Quiz Content
  • harmon 271
    Answered in Module Exam #2

    Briefly discuss the evidence for the semi-conservative replication of DNA

    Experiments by Matthew Meselson and Frank Stahl allowed E. coli to be labeled with 15N and 14N and then followed the density of the daughter cells using cesium chloride gradient centrifugation. They predicted that parental DNA molecules of one density which were allowed to replicate in another medium of a different density will show daughter DNA molecules of intermediate density because half will be old DNA and the other half will be new DNA. Their results proved that indeed half was old and other half was new indicating DNA of intermediate density.

  • harmon 271
    Answered in Module Exam #2

    Name the three major modifications of mRNA of eukaryotes before it is transported to the cytoplasm. In addition, tell why each of the modifications is necessary.

    Add 5’ cap (protect against degradation, acts as a binding site for the ribosome); add poly-A tail (possibly protect against degradation, possibly helps in the transfer of the mRNA to the cytoplasm); remove introns (forms a message that can be translated into a functional protein).

  • harmon 271
    Answered in Module Exam #2
    What is the fundamental difference between Group 1 and Group 2 self-splicing introns.
    Group 1 - found in rRNA genes, guanosine as a co-factor

    Group 2 - found in mRNA and tRNA of mitochondria and chloroplasts, no co-factor required.
  • harmon 271
    Answered in Module Exam #2
    Compare and contrast the in vivo role of DNA pol I and DNA pol III
    DNA pol I - removes the RNA primer. 5' --> 3' exonuclease activity and also 3' --> 5' exonuclease activity. Can fill in primer regions with DNA.

    DNA pol III - Only has 3' --> 5' exonuclease activity. Proofreading capabilities.