The part of cell that is responsible for the production of energy is

1. Analyze the question The question asks which cell organelle produces energy. In biology, this means the site of cellular respiration, where energy is released from food (glucose) in the form of ATP.

2. Explain the concept Each part of the cell has its own job:

• Cell membrane: controls what enters and leaves the cell.
• Cytoplasm: the jelly-like fluid where many chemical reactions take place. Glycolysis, the first stage of respiration, happens here, but it releases only a small amount of energy.
• Mitochondrion: the site of the Krebs cycle and the electron transport chain, which produce most of the cell's ATP (about 36-38 of the roughly 38 ATP made per glucose molecule). This is why it is called the "powerhouse of the cell".
• Nucleus: contains the DNA and controls the cell's activities, including growth and reproduction.

3. Step-by-step solution

• Step 1: The question asks about energy production, which means respiration.
• Step 2: Aerobic respiration releases most of its energy inside the mitochondria.
• Step 3: Check each option: • A: only regulates movement of substances, so it is wrong. • B: hosts only the early, low-yield stage of respiration, so it is not the main answer. • C: the powerhouse of the cell, so it is correct. • D: controls the cell and holds the genetic material, so it is wrong.

4. Answer The correct option is C. mitochondrion.

5. Exam tip Link each organelle to a one-line "job title":

• Mitochondrion = Powerhouse
• Nucleus = Control centre
• Ribosome = Protein factory
• Cell membrane = Gatekeeper
• Chloroplast = Food (photosynthesis) maker

Cells with high energy needs, such as muscle cells and sperm cells, have many mitochondria. JAMB often tests this link, so remember it.