Teaching Haryana (HPSC) Assistant Professor Mock Test 2025 Life Sciences Cell Communication and Cell Signaling Cancer
Apoptosis, or programmed cell death, is a crucial process in maintaining cellular homeostasis and development. It can be initiated through both intrinsic and extrinsic pathways, which involve different molecular signals and pathways. Which of the following statements accurately describes a key aspect of the intrinsic and extrinsic apoptotic pathways?
1
The intrinsic pathway is primarily activated by external signals such as tumor necrosis factor (TNF), leading to direct activation of caspase-8 and downstream executioner caspases.
2
In the extrinsic pathway, mitochondrial release of cytochrome c is a pivotal event that leads to the formation of the apoptosome, subsequently activating caspase-9 and downstream executioner caspases.
3
The intrinsic pathway is triggered by internal cell stress signals, including DNA damage and oxidative stress, leading to mitochondrial outer membrane permeabilization (MOMP) and the release of cytochrome c into the cytosol.
4
In both the intrinsic and extrinsic pathways, the activation of caspase-9 is the initial step that leads to the cascade of apoptotic events, ultimately resulting in cell death.
5
Question Not Attempted