Chapter 18

What is the difference between apoptosis and necrosis?

• Apoptosis is reversible, while necrosis is irreversible.
• Apoptosis results in inflammation, while necrosis does not.
• Apoptosis is programmed cell death, while necrosis is uncontrolled cell death.
• Apoptosis occurs in response to injury, while necrosis is a normal process.

What is the role of cdc25?

• Activates cyclin-dependent kinases (CDKs) by removing inhibitory phosphate groups
• Inhibits cyclin-dependent kinases (CDKs) by adding inhibitory phosphate groups
• Promotes cell cycle arrest
• Regulates DNA replication

Which cdk triggers the assembly of condensin complexes?

• M-Cdk

• S-Cdk4

• Interphase Cdk

• S-Cdk2

What is a key characteristic of prophase?

• Formation of the mitotic spindle
• Condensation of chromatin into visible chromosomes
• Disappearance of the nuclear envelope
• Expansion of chromatin into invisible chromosomes

What triggers the transition from G2 phase to mitosis?

• Activation of S-Cdk

• Degradation of cyclin-dependent kinases

• Activation of M-Cdk

• Inactivation of p53

Which process is primarily responsible for the separation of sister chromatids during mitosis?

• Condensin complex assembly

• Anaphase-promoting complex/cyclosome (APC/C) activation

• Cohesin complex breakdown

• Telomere elongation

What is the main function of telomerase?

• To replicate mitochondrial DNA

• To add repetitive nucleotide sequences to the ends of chromosomes

• To repair double-strand breaks in DNA

• To facilitate the binding of transcription factors

What role do centrosomes play in cell division?

• Organize microtubules to form the mitotic spindle
• Centrosomes store genetic material during division
• Centrosomes produce energy for cell division
• Centrosomes regulate cell shape during division

Which phase of mitosis is characterized by the alignment of chromosomes at the cell's equatorial plate?

• Prophase

• Metaphase

• Anaphase

• Telophase

What is the primary role of the spindle fibers during mitosis?

• To duplicate the DNA

• To condense the chromosomes

• To pull sister chromatids apart

• To break down the nuclear envelope