Cell Organelles: Mitochondria MCQs Quiz | Class 9

This Class IX Science (Code 086) quiz covers Unit II: Organization in the Living World. The specific topic is “Cell Organelles: Mitochondria,” focusing on its structure and basic role in energy production. Complete these 10 multiple-choice questions to test your understanding, view your score, and download a revision PDF.

Overview of Mitochondria

Mitochondria (singular: Mitochondrion) are vital cell organelles found in eukaryotic cells. Often referred to as the “powerhouse of the cell,” they are responsible for cellular respiration and the production of energy required for various chemical activities.

Structure and Components

Mitochondria have a unique double-membrane structure:

  • Outer Membrane: It is porous and covers the organelle.
  • Inner Membrane: It is deeply folded into finger-like structures called cristae. These folds significantly increase the surface area for ATP-generating chemical reactions.
  • Matrix: The space enclosed by the inner membrane, containing enzymes, DNA, and ribosomes.

Key Functions

The primary function is the release of energy in the form of ATP (Adenosine Triphosphate). ATP is known as the “energy currency” of the cell. The body uses energy stored in ATP for making new chemical compounds and for mechanical work.

Strange Organelles

Mitochondria are considered semi-autonomous or “strange” organelles because they have their own DNA and ribosomes. This allows them to synthesize some of their own proteins, distinct from the nucleus.

Quick Revision Table

Component Feature/Function
Cristae Folds of inner membrane to increase surface area.
ATP Energy currency produced by mitochondria.
Own DNA Allows synthesis of specific proteins.