Cell division is a complex process that occurs in all living things. Most cells have a limited number of times they can divide before the cell dies. This is why cancer can be a scary thing- if cells continue to divide uncontrollably, it can be hard to stop the growth.
Prokaryotic cells, or cells of bacteria, do not undergo the same type of cell division as eukaryotic cells, or cells of plants and animals. Prokaryotic cell division only has two stages– the first being DNA replication and the second being divided into two new cells.
Cell cycle is a series of events that take place in order during cell division. There are four distinct phases within the cell cycle: interphase, synthesis phase, mitosis phase, and cytokinesis phase. This article will discuss each phase and provide questions to determine which statement provides the best description of interphase portion of the cell cycle.
Cells double their DNA and prepare for mitosis
Following G1, the cell enters what is known as interphase. During interphase, the cell prepares to double its DNA and divide into two cells.
This process involves the DNA being unwound so the chromosomes can be replicated, proteins attaching to the DNA to organize it, and RNA molecules synthesized.
Interphase can last a few hours or several days, depending on the type of cell. During this time, the cell may also proliferate, or increase in size using the DNA material already present.
When interphase is complete, the cell enters mitosis, where it splits into two new cells. These cells are then ready to enter another phase of the cell cycle: either G0 or G1.
Cells divide their DNA and then divide the cells
As mentioned before, cells go through a series of stages as they divide. The first stage is the G1 phase, or gap 1 phase. In this stage, the cell grows in size and expresses genes that make it ready to divide. It also disassembles old components and assembles new ones as needed.
The second stage is the S phase, or synthesis phase. During this stage, the cell divides its DNA and then divides into two new cells. As this happens, the cell grows in size again due to cellular expression of genes needed for growth.
The third stage is the G2 phase, or gap 2 phase. In this stage, the cell again disassembles old components and assembles new ones as needed. The cell may still grow in size at this point.
Cells grow, prepare for DNA replication, and then divide
Within most cells, the process of cell division occurs in a specific order. This order is known as the cell cycle. The cell cycle consists of four distinct stages: G1, S, G2, and M.
During the G1 (gap 1) phase of the cell cycle, the cell prepares to double its DNA content. This includes growing and synthesizing proteins needed for this process.
During the S (synthesis) phase, the cell actually doubles its DNA content through a process called DNA replication. This happens in a defined period of time, usually taking about an hour.
The G2 (gap 2) phase follows S phase and is a transitional stage where the cells prepare to divide into two new cells. Some cells do not go through this stage before dividing.
The M (mitosis) phase is when the cell actually divides into two new cells. This happens via a process called mitosis that takes about an hour.
None of the options provide a correct description of interphase
The correct answer is B. Interphase is defined as the period of the cell cycle when the cell is not dividing.
Interphase consists of three phases: G1, S, and G2. The G stands for gap, which refers to the absence of synthesis occurring in these phases.
During G1, the cell prepares to enter mitosis by regulating proteins that control how the cell functions. Some of these proteins are activated by growth factors or other signals from outside the cell or from other cells.
G1 ends when synthesis begins, marking the start of Mitosis. In between these two stages, the cell undergoes some changes that make it ready to divide. These changes include creating structures that will split into two cells and synthesizing proteins needed for this process.
After a certain amount of time in G1, a signal occurs that prompts the cell to move into Mitosis.
