If a cell at G1 contains four picograms of DNA, how many picograms of DNA will it contain at the end of the S phase of the cell cycle? a. 0; b. 2; c. 4; d. 8

Verified step by step guidance

1. Understand the phases of the cell cycle, particularly focusing on the G1 phase and the S phase. The G1 phase is a period of growth before DNA replication, and the S phase is where DNA replication occurs.
2. Recognize that during the G1 phase, the cell contains a certain amount of DNA, which in this case is specified as four picograms.
3. Acknowledge that during the S phase, the cell's DNA is replicated. This means that each strand of DNA is duplicated to ensure that the two future daughter cells will each have a complete set of DNA.
4. Calculate the total amount of DNA in the cell at the end of the S phase by considering that the DNA content doubles as a result of replication.
5. Compare the calculated amount of DNA with the answer choices provided to determine the correct answer.

Key Concepts

Cell Cycle

The cell cycle is a series of phases that a cell goes through to grow and divide. It consists of interphase (which includes G1, S, and G2 phases) and the mitotic phase. During the S phase, DNA replication occurs, resulting in the duplication of the cell's genetic material.

DNA Replication

DNA replication is the process by which a cell makes an identical copy of its DNA. This occurs during the S phase of the cell cycle, where each chromosome is duplicated, leading to two sister chromatids for each chromosome. If a cell starts with a certain amount of DNA, it will double that amount by the end of the S phase.

Picogram Measurement

A picogram is a unit of mass equal to one trillionth of a gram (10^-12 grams). In the context of DNA, it is used to quantify the amount of genetic material present in a cell. Understanding this measurement is crucial for determining how much DNA is present before and after replication.