Question

Which of the following statements is incorrect?
a. Mitochondria, unless specifically stained are not easily visible under the microscope
b. Physiological activity of cells determines the number of mitochondria per cell
c. Mitochondria, a powerhouse of a cell has DNA, RNA, ribosomes and enzymes, so it can survive outside the cell
d. Mitochondria divide by fission

Answer 1

Mitochondria is a semi-autonomous membrane-bound organelle found in the cytoplasm of many eukaryotic cells, however, some mammalian cells lack mitochondria that is RBC, this is called as the powerhouse of the cell because it converts that energy obtained from food as ATP.

Complete answer:
- The mitochondria size is in the range of 0.75 and 3 micrometers.
- The size of the mitochondria varies and the structure also varies according to the type of the cell.
- Mitochondria is not like other cell organelles, where it is only visible if it is stained specifically.
- The main function of the mitochondria is to produce energy, and the other functions of the mitochondria include signaling, cellular differentiation, cell death, and they also maintain the growth of cell cycle and also cell growth as well.
- The number of the mitochondria is varied by the type of the cell, for example, RBC lacks the mitochondria and the liver cell contains more than 2000 mitochondria per cell.
- This mitochondrion is composed of compartments, which include the outer membrane, inner membrane, and the intermembrane space and also Cristae, matrix.
- Mitochondria has its own nucleus, and it has its own genome, apart from the cell nucleus.
- The production of ATP is vital for cell division of the mitochondria and also in the differentiation in case of infection.

Hence, the correct answer is option (C).

Note: Human mitochondria have their own genome and it is circular DNA, and the molecule contains about 10 kg bases, where it encoded almost 37 genes, and the code for respiratory complexes, tRNA, and one mitochondrion contain 2 to 10 copies of its DNA.