The organelle that is the site of the Krebs cycle in the cell is the: MCQ with Answer and Explanation

Explanation:
Cardiac muscle is striated, branched, and involuntary, with intercalated discs containing gap junctions for synchronized contraction. It is unique to the heart wall. Smooth muscle is non-striated and involuntary in visceral organs, skeletal muscle is striated and voluntary. Cardiac muscle exhibits autorhythmicity.

Explanation:
Solar energy is converted to chemical energy by photosynthesis, driving nearly all ecosystems. Only deep-sea vents rely on chemosynthesis.

Explanation:
Tuberculosis is a bacterial disease caused by Mycobacterium tuberculosis, primarily affecting the lungs. Polio is a viral disease caused by the poliovirus, attacking the nervous system. Tetanus is caused by the bacterium Clostridium tetani, which produces a neurotoxin that causes severe muscle spasms and affects the nervous system. Thus, only statement 3 is correct.