L2 MCQ - The Ultimate Cell Cycle Quiz

Cell Cycle Phases

• DNA replication occurs during the S phase of the cell cycle.
• The G1 checkpoint is a crucial phase in the cell cycle that ensures the cell is ready to enter the S phase, and it's where the cell checks for any DNA damage or other issues.
• The two basic things that cells must accomplish during the cell cycle are growth (increasing in size) and division (splitting into two daughter cells).

Mitosis Phases

• The phase of the cell cycle that corresponds to the division activity is Mitosis.
• During the Anaphase phase of mitosis, the chromatids separate and move toward the opposite spindle poles.
• The breakdown of the nuclear envelope occurs during the Prophase phase of mitosis.

Cell Division Structures

• The centrosome is responsible for the duplication of the centrioles, and it plays a crucial role in the formation of the spindle fibers during cell division.
• The function of centrioles in cell division is to form the spindle fibers, which are essential for the separation of chromosomes during mitosis.

Cell Cycle Regulation

• The main function of cyclin-dependent kinases (CDKs) in the cell cycle is to trigger the progression of the cell cycle by phosphorylating and activating other proteins.
• The cyclin-Cdk complex that is responsible for the activation of mitosis is the cyclin B-Cdk1 complex.
• Cyclin-dependent kinase inhibitors (CDKIs) play a crucial role in cell cycle regulation by inhibiting the activity of CDKs, thereby preventing the cell from entering the next phase of the cell cycle.

Mitosis and Cytokinesis

• The cleavage furrow is a structure that forms in the cell membrane during cytokinesis, and its function is to divide the cell into two daughter cells.
• Histones play a crucial role in mitosis by compacting the DNA into chromosomes, making it easier to separate and move during cell division.
• DNA topoisomerase II is an enzyme that plays a crucial role in mitosis by relieving the tension that builds up in the chromosomes as they condense and separate during cell division.