Q.Why can a red muscle work for a prolonged period whereas a white muscle fibre suffers from fatigue after a shorter period of work? (Refer to the chapter on Animal Tissues.)

Step 1. Red muscle fibres (slow-twitch fibres) contain abundant myoglobin (which stores and supplies oxygen within the fibre), numerous mitochondria, and a rich capillary blood supply.

Step 2. This lets red fibres sustain aerobic respiration for long periods, generating ATP steadily without a large build-up of lactic acid — so they can work for a prolonged period without fatiguing quickly. …

Compare the aerobic capacity (myoglobin/mitochondria/blood supply) of red versus white fibres and link it to how qui …

• Describing the difference only as 'red fibres are stronger' rather than explaining the underlying aerobic-vs-anaerobic metabolic basis. …