The genome of D. melanogaster consists of approximately 1.7x10⁸ base pairs. DNA synthesis occurs at a rate of 30 base pairs per second. In the early embryo, the entire genome is replicated in five minutes. How many bidirectional origins of synthesis are required to accomplish this feat?

Key Concepts

Genome Size

The genome size refers to the total amount of genetic material contained within an organism's DNA, measured in base pairs. In the case of D. melanogaster, the genome consists of approximately 1.7x10⁸ base pairs. Understanding genome size is crucial for calculating the time and resources needed for DNA replication.

DNA Replication Rate

DNA replication rate is the speed at which DNA polymerases synthesize new DNA strands, typically measured in base pairs per second. For D. melanogaster, this rate is approximately 30 base pairs per second. This concept is essential for determining how long it will take to replicate the entire genome and how many replication origins are needed.

Bidirectional Origins of Synthesis

Bidirectional origins of synthesis are specific sites on the DNA where replication begins, allowing the process to occur in two directions simultaneously. This mechanism significantly increases the efficiency of DNA replication. To replicate the entire genome within a limited time, calculating the number of these origins is necessary based on the total genome size and replication rate.