Apoptosis Quiz

Cytochrome c release from the mitochondria, which plays a crucial role in the intrinsic pathway of apoptosis, is directly regulated by:

• A) Fas ligand (FasL)

• B) Bcl-2 family proteins

• C) Caspase-8

• D) TNF-α

The activation of initiator caspases (e.g., caspase-8, caspase-9) in apoptosis leads to:

• A) The direct cleavage of cellular proteins to initiate cell death

• B) The production of inflammatory cytokines

• C) The activation of effector caspases, which then execute the cell death program

• D) The transcription of pro-survival genes

In the context of the extrinsic pathway of apoptosis, which of the following statements is true?

• A) It is mainly triggered by internal stress signals like DNA damage.

• B) It involves the activation of procaspase-9.

• C) It is initiated through death receptors on the cell surface.

• D) It is regulated primarily by the mitochondrial release of Smac/DIABLO.

Which of the following is a major difference between the intrinsic and extrinsic pathways of apoptosis?

• A) Only the intrinsic pathway involves caspases.

• B) Only the extrinsic pathway can be inhibited by Bcl-2 proteins.

• C) The intrinsic pathway is activated by external signals, while the extrinsic pathway is activated by internal stress.

• D) The intrinsic pathway involves mitochondrial signals, whereas the extrinsic pathway is triggered by death receptor signaling.

The intrinsic pathway of apoptosis is primarily activated by:

• A) External signals such as ligand-receptor interactions

• B) Direct damage to the DNA and disruption of the mitochondrial membrane potential

• C) Activation of death receptors on the cell surface

• D) Release of cytotoxic T lymphocytes

Which of the following is a key feature distinguishing apoptosis from necrosis?

• A) Inflammation surrounding the dying cells

• B) Swelling of the dying cell and its organelles

• C) Cell shrinkage and formation of apoptotic bodies

• D) Release of cellular contents into the surrounding tissue