Question

Choose the correct statement about mitochondria
A. Mitochondria exist in all eukaryotes
B. Mitochondria exist in bacteria and plants
C. Mitochondria exist in animal, plant and fungi
D. Both B and C
E. Both A and C

Answer 1

Hint: Mitochondria is a cylindrical or sausage-shaped double membraned organelle distributed in the cytoplasm. They are stained by the vital stain Janus green for visualization. They also show a great degree of variability in their shape, size, and number.

Complete answer:
- As previously mentioned, mitochondria are surrounded by a double membrane system, the inner and outer mitochondrial membrane. The outer membrane is smooth while the inner membrane has numerous folds called cristae and are rich in cardiolipin.
- Due to the presence of a double membrane system, the organelle is divided into two compartments, the outer intermembrane space also called the peri-mitochondrial space, and the inner compartment/matrix.
- As per the mitochondrial functions, the membranes have their respective enzymes. The cristae comprises the Particles of Fernandez and Moran. Their head contains ATP synthase which brings about oxidative phosphorylation coupled with ATP release.
- Since bacterias lack all the membranous structures, mitochondria are not present in them. However, all the eukaryotes including plants, animals, and fungi have mitochondria present in their cells.

Hence, the correct answer is option (E).

Note: It was first discovered by the physiologist Albert von Kolliker in 1857.
- Carl Benda coined the term “mitochondria”.
- It is often known as the “powerhouse of the cell”.
- It’s yellow in color due to the presence of Riboflavin.
- Many mitochondria are collectively known as “Chondrion”
- Succinyl dehydrogenase is the marker enzyme of this organelle.
- Genes for cytoplasmic male sterility in plants are generally located in the mitochondrial genome.