KA2- Structure And Replicaion Of DNA

Question 1

Structure and replication of DNA

Answer 1

Nucleotides (deoxyribose sugar, phosphate and base), sugar-phosphate backbone, base pairing (adenine-thymine and guanine-cytosine), by hydrogen bonds and double stranded anti parallel structure, with deoxyribose and phosphate at 3’ and 5’ ends of each strand, respectively, forming a double helix.
The base sequence of DNA forms the genetic code

Question 2

Template DNA

Answer 2

Provides the code to copy

Question 3

DNA nucleotides

Answer 3

Produce the new strand of DNA

Question 4

Supply of ATP

Answer 4

Provide the enzymes with energy

Question 5

Polymerase chain reaction

Answer 5

Amplifies DNA using complementary primers for specific target sequences
Repeated cycles of heating and cooling amplify the target region of DNA

Question 6

Primers in PCR

Answer 6

In PCR, primers are short strands of nucleotides which are complementary to specific target sequences at the two ends of the region of DNA to be amplified

Question 7

Stage 1 PCR

Answer 7

DNA is heated to between 92 and 98 degreesC to separate the strands

Question 8

Stage 2 PCR

Answer 8

It is the cooled to between 50 and 65 degreesC to allow primers to bind to target sequences

Question 9

Stage 3 PCR

Answer 9

It is then heated to between 70 and 80 degreesC for heat-tolerant DNA polymerase to replicate the region of DNA

Question 10

Practical applications of PCR

Answer 10

PCR can amplify DNA to help solve crimes, settle paternity suits and diagnose genetic disorders