#programmed cell death

Apoptosis

Initiator caspases in mammals include

Initiator caspases (caspase-8, -9 and -10) are activated by dimerization within large multiprotein platforms such as the DISC or the apoptosome. Once active they cleave and thereby activate the executioner caspases (caspase-3, -6 and -7). Executioner caspases proteolytically dismantle structural proteins, activate nucleases and ultimately produce the morphological hallmarks of apoptosis.

Ref: NCERT Biology Class 11–12 Alberts et al Molecular Biology of the Cell Lodish et al, Molecular Cell Biology Cooper & Hausman, The Cell Abbas et al., Cellular and Molecular Immunology (for immunology sections)

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Apoptosis

Which feature is NOT associated with apoptosis?

Inflammation, is consistent with established principles of cell signaling, receptor pharmacology and cellular regulation. Experimental measurements of binding parameters, genetic loss-of-function studies and pharmacological interventions all converge on the same interpretation. Related options address neighboring concepts but do not satisfy the precise criterion stated in the question.

Ref: NCERT Biology Class 11–12 Alberts et al Molecular Biology of the Cell Lodish et al, Molecular Cell Biology Cooper & Hausman, The Cell Abbas et al., Cellular and Molecular Immunology (for immunology sections)

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Apoptosis

During the latent phase of apoptosis, the cell

Apoptosis is an orderly, energy-dependent form of programmed cell death that eliminates cells without provoking inflammation. Characteristic morphological features include cell shrinkage, chromatin condensation (pyknosis), nuclear fragmentation (karyorrhexis), membrane blebbing and formation of apoptotic bodies that display phosphatidylserine as an “eat-me” signal for phagocytes. Rapid clearance of these bodies prevents release of intracellular contents and subsequent inflammation.

Ref: NCERT Biology Class 11–12 Alberts et al Molecular Biology of the Cell Lodish et al, Molecular Cell Biology Cooper & Hausman, The Cell Abbas et al., Cellular and Molecular Immunology (for immunology sections)

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Apoptosis

The two major phases of apoptosis are

Latent and execution phases, is consistent with established principles of cell signaling, receptor pharmacology and cellular regulation. Experimental measurements of binding parameters, genetic loss-of-function studies and pharmacological interventions all converge on the same interpretation. Related options address neighboring concepts but do not satisfy the precise criterion stated in the question.

Ref: NCERT Biology Class 11–12 Alberts et al Molecular Biology of the Cell Lodish et al, Molecular Cell Biology Cooper & Hausman, The Cell Abbas et al., Cellular and Molecular Immunology (for immunology sections)

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Apoptosis

Apoptosis is best defined as

Apoptosis is an orderly, energy-dependent form of programmed cell death that eliminates cells without provoking inflammation. Characteristic morphological features include cell shrinkage, chromatin condensation (pyknosis), nuclear fragmentation (karyorrhexis), membrane blebbing and formation of apoptotic bodies that display phosphatidylserine as an “eat-me” signal for phagocytes. Rapid clearance of these bodies prevents release of intracellular contents and subsequent inflammation.

Ref: NCERT Biology Class 11–12 Alberts et al Molecular Biology of the Cell Lodish et al, Molecular Cell Biology Cooper & Hausman, The Cell Abbas et al., Cellular and Molecular Immunology (for immunology sections)

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Phytohormone ALL PYQS

GA delays programmed cell death in aleurone by antagonizing:

Pick C: ABA. Thinking through Phytohormone ALL step by step rules out the lookalikes and leaves ABA. Skip these: A) Auxin; B) Cytokinin; D) Ethylene. For hormones and genes, match the molecule or gene to its real role, not a neighboring pathway.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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Gibberellins

Programmed cell death in cereal aleurone is promoted by:

Correct option is B, GA. In Gibberellins problems like this, the accurate statement is GA; the others are common mix-ups. Not these: A) ABA; C) Ethylene; D) Auxin. Tissue transport questions usually turn on xylem vs phloem, living vs dead cells, or source vs sink.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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