Question

Antiparallel strands of a DNA molecule means that

• A. One strand turns anti-clockwise
• B. The phosphate groups of two DNA strands at their ends, share the-same position
• C. The phosphate groups at the start of two DNA strands are in opposite position (pole)
• D. One strand turns clockwise

Answer 1

Answer: (C)

The phosphate groups at the start of two DNA strands are in opposite position (pole)

Answer 2

The antiparallel strands of a DNA molecule means that the phosphate groups at the start of two DNA strands are in opposite position (pole).

Watson and Crick (1953) showed that structure of DNA is a double helical containing two polynucleotide chains connected by hydrogen bonds and running antiparallel. Antiparallel means that the two strands of aDNAmolecule run in opposite directions , parallel to one another. One strand is in the direction of 5' to 3' and another is in 3' to 5'. The main purpose behind the antiparallel direction of the two strands is to provide stability to the DNA.