locating genes

Question 1

how do you diagnose disease like Hunters syndrome

Answer 1

we need to locate the mutated DNA sequence gene

to do this you use a DNA probe

Question 2

what are the 2 types of DNA probe

Answer 2

radioactive
fluorscent

Question 3

what are the 3 characteristics of a DNA probe

Answer 3

short
single stranded
label attached

Question 4

how could you make a DNA probe

Answer 4

• make DNA with the complementary base sequence to desired allele
• copy using PCR
• attach marker

Question 5

define DNA hybridisation

Answer 5

when a section of DNA or RNA binds with a single stranded section of DNA with complementary bases

Question 6

explain how a DNA probe and DNA hybridisation can be used to determine whether a foetus has Hunter syndrome
(6 marks)

Answer 6

• determine the sequence of nucleotide bases of the mutant allele
  (DNA sequencing)
• make a probe that has complementary bases to the mutated gene
• separate the DNA to make it single stranded by heating
• mix separate strands of DNA sample with DNA probe and cool
• DNA probe will bind to the complementary base sequence pf the mutated gene on the DNA sequence (DNA hybridisation)
• wash away any unbound DNA probes
• site where the probe has bound is identified by the radioactivity or fluorescence that the probe emits