1. What are the various phases that make up the cell cycle? Explain what happens during each phase. (4 marks)
The cell cycle consists of many stages, which are separated into two phases: interphase and mitosis. During interphase, the cell grows larger and makes a copy of its own DNA. Interphase occurs for about 90% of the cell cycle and consists of the following stages:
G1 phase, during which the cell grows larger and produces more of its organelles, proteins, and ribosomes. This phase ensures the division of the cell will produce daughter cells. G1 phase begins when a cell is produced and is completed when S phase occurs.
S phase, for it to be able to divide, a cell must produce a replica of its genetic material, which allows it to give one complete set to each of its two daughter cells. To ensure this happens, the cell moves from G1 phase into S phase, during which it synthesizes a …show more content…
(Reece et al. 2014)
The Mitotic (M) Phase occurs in two parts: Mitosis and Cytokinesis
During mitosis the DNA of the cell condenses into chromosomes and removed by the mitotic spindle. Mitosis takes place in four stages: prophase, prometaphase, metaphase, anaphase, and telophase.
In cytokinesis, the cytoplasm of the cell is split in two, making two new cells. Cytokinesis usually begins just as mitosis is ending, with a little overlap. Cytokinesis is different in plant cells and animal cells. (Reece et al. 2014)
2. How is the eukaryotic cell cycle regulated? (3 marks)
The Biology Project indicates that the cell cycle uses CDKs and Cyclins (G1 and Mitotic) for regulation:
Cyclin-Dependent Kinase (CDK) is an enzyme the process of phosphorylation. A CDK tells the cell that it is ready to continue on to the next stage of the cell cycle. Cyclins bind to CDKs and then activates the CDKs to phosphorylate other molecules in the cell
The cell cycle consists of many stages, which are separated into two phases: interphase and mitosis. During interphase, the cell grows larger and makes a copy of its own DNA. Interphase occurs for about 90% of the cell cycle and consists of the following stages:
G1 phase, during which the cell grows larger and produces more of its organelles, proteins, and ribosomes. This phase ensures the division of the cell will produce daughter cells. G1 phase begins when a cell is produced and is completed when S phase occurs.
S phase, for it to be able to divide, a cell must produce a replica of its genetic material, which allows it to give one complete set to each of its two daughter cells. To ensure this happens, the cell moves from G1 phase into S phase, during which it synthesizes a …show more content…
(Reece et al. 2014)
The Mitotic (M) Phase occurs in two parts: Mitosis and Cytokinesis
During mitosis the DNA of the cell condenses into chromosomes and removed by the mitotic spindle. Mitosis takes place in four stages: prophase, prometaphase, metaphase, anaphase, and telophase.
In cytokinesis, the cytoplasm of the cell is split in two, making two new cells. Cytokinesis usually begins just as mitosis is ending, with a little overlap. Cytokinesis is different in plant cells and animal cells. (Reece et al. 2014)
2. How is the eukaryotic cell cycle regulated? (3 marks)
The Biology Project indicates that the cell cycle uses CDKs and Cyclins (G1 and Mitotic) for regulation:
Cyclin-Dependent Kinase (CDK) is an enzyme the process of phosphorylation. A CDK tells the cell that it is ready to continue on to the next stage of the cell cycle. Cyclins bind to CDKs and then activates the CDKs to phosphorylate other molecules in the cell