Pick the incorrect statement

The correct option is "mitochondria is the site for calvin cycle".

Let us analyze each statement step-by-step to understand why this statement is incorrect and the others are correct:
1. Mitochondrial DNA is known as mtDNA: Mitochondria possess their own extrachromosomal DNA, which is circular and double-stranded. This specific DNA is universally abbreviated and referred to as mtDNA. Therefore, this statement is factually correct.
2. Mitochondria is the powerhouse of the cell: Mitochondria are responsible for generating adenosine triphosphate (ATP), which acts as the primary energy currency of the cell. Because they produce the energy required for various cellular activities, they are widely known as the powerhouse of the cell. Therefore, this statement is factually correct.
3. Mitochondria is the site for krebs cycle and oxidative phosphorylation: In eukaryotic cells, the Krebs cycle (also known as the citric acid cycle) takes place in the mitochondrial matrix, while oxidative phosphorylation and the electron transport chain occur across the inner mitochondrial membrane. Therefore, this statement is factually correct.

4. Mitochondria is the site for calvin cycle: The Calvin cycle (the light-independent reactions of photosynthesis) is the process by which plants and other autotrophs fix carbon dioxide to synthesize glucose. This cycle takes place in the stroma of the chloroplasts, not in the mitochondria. Therefore, this statement is incorrect.