A cell has a mutation that makes primase very inefficient. What defect would you likely observe?

A cell has a mutation that makes primase very inefficient. What defect would you likely observe?

• A. A delay in unwinding the DNA
• B. A rapid replication of the lagging strand, but slow replication of the leading strand
• C. A longer time to replicate DNA
• D. Inefficient joining of the Okazaki fragments

Answer: (C)

The correct answer highlights that a mutation making primase inefficient would notably lead to a longer time to replicate DNA. Primase is responsible for synthesizing short RNA primers that are essential for DNA polymerase to initiate DNA replication. These primers serve as starting points for the elongation of the new DNA strands. If primase is functioning inefficiently, it will produce fewer primers, or the process of primer synthesis will be slower. This means that DNA polymerase will spend more time waiting for these primers to be available before it can begin the replication process. Consequently, the overall speed of DNA replication will slow down, leading to an increased duration to complete the replication. While other options discuss different aspects of DNA replication, they do not directly address the core issue arising from an inefficient primase. For example, unwinding DNA and the joining of Okazaki fragments are processes dependent on other proteins and enzymes and would not be directly impacted by the efficiency of primase alone. Thus, focusing on the overall time taken for DNA replication effectively captures the primary consequence of the mutation affecting primase.

The correct answer highlights that a mutation making primase inefficient would notably lead to a longer time to replicate DNA. Primase is responsible for synthesizing short RNA primers that are essential for DNA polymerase to initiate DNA replication. These primers serve as starting points for the elongation of the new DNA strands.

If primase is functioning inefficiently, it will produce fewer primers, or the process of primer synthesis will be slower. This means that DNA polymerase will spend more time waiting for these primers to be available before it can begin the replication process. Consequently, the overall speed of DNA replication will slow down, leading to an increased duration to complete the replication.

While other options discuss different aspects of DNA replication, they do not directly address the core issue arising from an inefficient primase. For example, unwinding DNA and the joining of Okazaki fragments are processes dependent on other proteins and enzymes and would not be directly impacted by the efficiency of primase alone. Thus, focusing on the overall time taken for DNA replication effectively captures the primary consequence of the mutation affecting primase.