University of Phoenix Material
Comparing Cell Cycles
Complete the Cell Cycle charts below. Describe the events in each phase for Cell Cycle A. Compare the steps in mitosis and meiosis for Cell Cycle B.
Cell Cycle A
Phase
Describe the events in each phase
G1 (1st growth stage)
When a cell passes the G1 checkpoint it enters the S phase of the cell cycle. During this phase DNA is replicated 3. After DNA replication, the cell leaves S phase and enters G2, when the cell prepares for mitosis or meiosis. At the G2 checkpoint, the cell checks two things.
S (Synthesis)
To produce two similar daughter cells, the complete DNA instructions in the cell must be duplicated. DNA replication occurs during this S (synthesis) phase. Depending on levels of nutrients, energy and external factors, cells must decide to enter the cell cycle or move into a non-dividing state known as G0
G2 (2nd growth stage)
Occurring between the end of DNA replication in S phase and the beginning of cell division in mitosis, G2 can be thought of as a safety gap during which a cell can check to make sure that the entirety of its DNA and other intracellular components have been properly duplicated.
Prophase of mitosis
Prophase is the first stage in mitosis, occurring after the conclusion of the G2 portion of interphase. During prophase, the parent cell chromosomes which were duplicated during S phase condense and become thousands of times more compact than they were during interphase.
Metaphase of mitosis
The chromosomes become arranged on the metaphase plate and are attached to the now fully formed spindle. The centrosomes are at opposite poles of the cell. The chromosomes, now at their most highly coiled and condensed, become arranged on a plane equidistant from the two poles called the metaphase plate.
Anaphase of mitosis
Sister chromatids separate, and the now-daughter chromosomes move to opposite poles of the cell. Anaphase begins when the duplicated centromeres of...