Part A: Short-answer questions 1. What does "antiparallel" mean? In the same context, how do we describe the direction of a single DNA strand? (4) 2. Explain the concept of semiconservative replication. (2) 3. Explain why DNA replication could not occur in the absence of RNA primers. (2)

1. Antiparallel means two molecules which are side by side and moving in opposite direction.

Single DNA strand runs from 5' to 3' in opposite direction from one another.

2. Two copies of the original DNA molecule are produced and each of them replicates the information from one half of the original DNA molecule.

3. RNA primers mainly serves as starting point of DNA polymerase which builds complementary DNA.

Primers are the small pieces of RNA.

DNA replication could not occur in absence of RNA primer because the RNA primer only provides the starting point for DNA synthesis.

Step-by-step explanation

1. Antiparallel means two molecules which are side by side and moving in opposite direction.

Single DNA strand runs from 5' to 3' in opposite direction from one another.

2. Two copies of the original DNA molecule are produced and each of them replicates the information from one half of the original DNA molecule.

The parent strand is separated while creating two single strand in which each strand is used as template for the complementary strand.

3. RNA primers mainly serves as starting point of DNA polymerase which builds complementary DNA.

Primers are the small pieces of RNA.

DNA replication could not occur in absence of RNA primer because the RNA primer only provides the starting point for DNA synthesis.