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#Question id: 762


Regarding the sugar residues in nucleic acids, which, if any, of the following statements is incorrect?

#Unit 1. Molecules and their Interaction Relevant to Biology
  1. The sugar is always based on a heterocyclic ring that consists of one oxygen atom and four carbon atoms, one of which is connected to a fifth carbon atom, the 5’ carbon atom.

  2. The internal sugar residues in a DNA strand normally have free hydroxyl groups, unlike those in an RNA strand.

  3. Bases are covalently linked to the carbon 1’ atoms of the sugars.

  4. Neighboring sugar residues are linked to each other by a phosphodiester bond that connects the 3’ carbon atom on one sugar to the 5’ carbon atom of its neighbour.

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TLS Online TPP Program

#Question id: 5750

#Unit 8. Inheritance Biology

 type of microorganism that can exist on minimal medium

TLS Online TPP Program

#Question id: 5752

#Unit 8. Inheritance Biology

base change that changes a codon for an amino acid to a stop codon

TLS Online TPP Program

#Question id: 5753

#Unit 8. Inheritance Biology

A bacterial histidine mutant was plated on minimal medium and a single colony grew. You decide to sequence the histidine biosynthetic gene of the revertant and discover that the original mutation is still present.  This colony must have been able grow due to a

TLS Online TPP Program

#Question id: 5754

#Unit 8. Inheritance Biology

A cell is exposed to EMS (a mutagen that causes guanine to mispair with thymine) and allowed to undergo a few rounds of DNA replication.  The mutational event caused by this mutagen will be

TLS Online TPP Program

#Question id: 5755

#Unit 8. Inheritance Biology

A researcher studying bacterial toxin predicts that a lysine within the toxin is important for binding it’s target cell.  She used site-directed mutagenesis to change a codon for lysine (AAA) to one for asparagine (AAU).  However, the mutant toxin still binds to its target cell just as well as the wild-type toxin bound and appears to have no other changes. This type of mutation is probably

TLS Online TPP Program

#Question id: 5756

#Unit 8. Inheritance Biology

Type of mutation caused by an addition or deletion of a base in a polypeptide-encoding part of a gene