[Campbell Biology P.280] Based on the information provided, what are the likely consequences... | Practice Question

Based on the information provided, what are the likely consequences if apoptosis is dysregulated, specifically if it fails to occur when it should or occurs when it should not, and which protein defects could be implicated?

  • A: If apoptosis fails to occur when it should, it could lead to the persistence of webbed digits or contribute to cancer due to cell suicide failure; defects in proteins like Ced-4 are implicated.
  • B: If apoptosis occurs when it should not, it could result in Parkinson's or Alzheimer's disease due to neuronal cell loss; defects in proteins involved in DNA repair might be the cause.
  • C: Both failure of apoptosis and inappropriate apoptosis always involve faulty cell-surface receptors, leading to autoimmune disorders.
  • D: Abnormal apoptosis solely affects embryonic development, leading to conditions like syndactyly, but has no role in adult degenerative diseases.

Explanation

The text explicitly states that 'in the case of humans, the failure of appropriate apoptosis can result in webbed fingers and toes,' and that 'cancer can result from a failure of cell suicide; some cases of human melanoma, for example, have been linked to faulty forms of the human version of the C. elegans Ced-4 protein.' This directly supports option A. Other options contain inaccuracies or statements not supported by the provided text.