During the G1 phase of the cell cycle, how does the rate of cell growth typically change?

• A. It increases as the cell prepares for DNA replication.
• B. It decreases because the cell is dividing.
• C. It stops completely until mitosis begins.
• D. It remains constant throughout the entire cell cycle.

Answer: (A)

Verified step by step guidance

1. Understand the G1 phase of the cell cycle: The G1 phase is the first gap phase after cell division (mitosis) and before DNA replication (S phase). During this phase, the cell grows in size and synthesizes proteins and organelles necessary for DNA replication and subsequent cell division.
2. Consider the biological processes occurring during G1: The cell is actively preparing for DNA replication, which requires an increase in cellular components such as enzymes, nucleotides, and energy stores. This preparation typically involves an increase in the rate of cell growth.
3. Evaluate the options provided: Analyze each statement in the context of the G1 phase. For example, the statement 'It increases as the cell prepares for DNA replication' aligns with the biological activities of the G1 phase, while 'It decreases because the cell is dividing' is incorrect because division occurs during mitosis, not G1.
4. Eliminate incorrect answers: The statement 'It stops completely until mitosis begins' is incorrect because the cell is actively growing during G1. Similarly, 'It remains constant throughout the entire cell cycle' is incorrect because growth rates vary depending on the phase of the cell cycle.
5. Conclude with the correct understanding: The rate of cell growth typically increases during the G1 phase as the cell prepares for DNA replication, making this the correct answer.