Biotechnology

8 flashcards · Biology · by Vanda Reiss

1. What is the open reading frame?

   stretch of DNA or RNA that encodes a protein - not interrupted by stop codons

2. How does gel electrophoresis separate DNA molecules?

   negative phosphate backbone moves towards positive electrode when current is passed through. agarose gel acts as a sieve: DNA molecules are slowed down more by the agarose, so do not travel as far.

3. Difference between Type I and Type II restriction enzymes

   Type I cut the DNA strand 1000 or more base pairs from the recognition sequence Type II: cut in the middle of the recognition sequence and are the most useful for genetic engineering

4. What is hybridisation used for?

   to determine whether sequences in two separate samples of DNA or RNA are related.

5. In hybridization experiments, the term probe molecule refers to...

   a known DNA sequence or gene that is used to screen the experimental sample

6. Southern blots are used to...

   determine how closely DNA from one source is related to a DNA sequence from another source

7. What is the difference between a Northern Blot and a Southern Blot?

   Southern blots use DNA, Northern uses RNA

8. describe Fluorescence in situ hybridisation

   fluorescent probe (small segment of DNA) is hybridised directly into cell onto its homologous sequence can label specific sections of DNA and identify their location on chromosome using fluorescence microscopy