A ring of actin filaments contract to form a ________ that pinches the two daughter cells apart.

A. areolar CT:Areolar connective tissue provides support and flexibility beneath epithelial layers but does not line tubular structures like the kidney tubules.

B. simple columnar ET:Simple columnar epithelium is specialized for absorption and secretion in areas like the gastrointestinal tract. Its taller cells are not suited for the thin, absorptive lining required in kidney tubules.

C. nonkeratinized stratified squamous ET:This epithelium protects against abrasion in areas such as the esophagus and oral cavity, but its multiple layers and thickness make it inappropriate for kidney tubules where rapid exchange occurs.

D. simple squamous ET:Simple squamous epithelium allows rapid diffusion and is found in structures like the glomerulus, but it is too thin for the majority of the kidney tubules, which require more absorptive and secretory capacity.

E. simple cuboidal ET:Simple cuboidal epithelium forms the lining of most kidney tubules. Its cube-shaped cells provide the surface area necessary for absorption and secretion while maintaining a single-cell layer for efficient transport of substances.

False:Pyruvic acid is converted into lactic acid only under anaerobic conditions, when oxygen is insufficient for the mitochondria to carry out aerobic respiration. When oxygen is present, pyruvic acid enters the mitochondria and is converted into acetyl CoA, which then enters the Krebs cycle for aerobic respiration. Lactic acid formation does not occur under these oxygen-rich conditions.