Biology: Mitosis and Apoptosis

Mitosis

• Nucleolus disappears during Prophase.
• Centrosome is the structure where the assembly of microtubules of the mitotic spindle begins.
• Proteins encoded by tumor suppressor genes prevent uncontrolled cell growth.
• Statement "In prometaphase, the chromosomal material called chromatin condenses" is False.
• In G2 phase, transcription and translation of genes that encode proteins necessary for cell division occur.
• In animal cells, cytokinesis occurs through segmentation.
• In telophase, the mitotic spindle breaks down, the nucleolus reappears, and a nuclear membrane forms around the chromosomes.
• G2 is the checkpoint where complete DNA replication is verified.
• Cyclin levels rise and fall during cell cycle regulation.
• Alignment of chromosomes on the metaphase plate is an internal control signal of the M phase.

Apoptosis

• When cells do not respond to control mechanisms, they produce cancer cells.
• Apoptosis is programmed cell death.
• In necrosis, a cell bursts, spilling its contents.
• The function of the apoptosome is to activate procaspase-9.
• In the proteolytic cascade, the activation of effector caspases is due to cleavage of their prodomains.
• Growth factors stimulate cell growth.
• G1 is the phase of the cell cycle where cell growth occurs.
• During prometaphase, the nuclear envelope fragments.
• Cells that undergo apoptosis die cleanly.
• Apoptosis is mediated by an intracellular proteolytic cascade.
• p53 is considered a tumor suppressor gene.
• Necrosis is characterized by bursting and swelling.
• Two procaspases are required to form an active caspase.
• After cleavage of the prodomains, procaspases must assemble.
• The phase where an active caspase can activate many other caspases is called amplification.
• Nuclear lamina degradation can occur in a cell when a proteolytic cascade is activated.
• Procaspases must undergo cleavage and assembly to form an active caspase.

Test your knowledge of cell division and regulation with this quiz on mitosis and apoptosis. Learn about the stages of mitosis, cell growth regulation, and the mechanisms of apoptosis.