Growth and reproduction of cells Transitional Reasoning Download PDF

Questions

1. 1.

   During interphase, an animal cell continuously synthesizes proteins, lipids, and organelles, leading to a steady increase in cytoplasmic volume and cell size. While the internal volume of the growing cell expands as a function of the cube of its radius, the surface area of its plasma membrane increases only as a function of the square of its radius. If a genetic mutation prevents this cell from initiating division once it surpasses its normal size threshold, which physiological constraint will most directly jeopardize its survival?

   • A) The nucleus becomes physically incapable of transcribing essential genes due to dilution of transcription factors in the enlarged cytoplasm.
   • B) The inner mitochondrial membranes spontaneously rupture under increased hydrostatic pressure generated by excess cytosolic water.
   • C) The rate of transmembrane nutrient absorption and waste removal becomes insufficient to support the metabolic demands of the increased volume.
   • D) The microfilament cytoskeleton rapidly depolymerizes due to mechanical tensile stress across the expanded cellular boundaries.