Question

______ has its own DNA
A. Peroxisome
B. Mitochondria
C. Dictyosome
D. Lysosome

Answer 1

Hint: Though mitochondria are known as the powerhouse of the cell, it has other functions as well such as cellular metabolism, the citric acid cycle, it produces heat, controlling the concentration of calcium levels and helps with the production of certain steroids.

Complete answer: Mitochondria is cylindrical in shape and is a double membrane organelle. It is distributed in the cytoplasm. They have two membranes known as outer and inner membranes. There is a matrix present within the inner membrane that contains a single circular dsDNA along with RNA molecules and 70s ribosomes. It also contains some components for the production of proteins. Mitochondria are also regarded as semi-autonomous cell organelles because it has the capability of self-duplication as has its own DNA like the nucleus. Mitochondria function as batteries as they produce more than 90% of the energy in the body via cellular respiratory processes. Mitochondria are really important in high-energy demanding organs such as the heart, liver, muscles and brain. 40% of the heart muscle cell and 25% of each liver cell contains mitochondria. Symbiosis is referred to as the relationship between two separate species which live in a very close affinity. Similarly, endosymbiosis is a type of symbiosis where one organism may live inside the other. As we know that bacteria, mitochondria and chloroplast are similar in size, but bacteria have DNA and ribosomes similar to that of mitochondria.
Hence, the correct answer is option B.

Note: Many scientists believe that years ago, bacteria may have formed an endosymbiotic relationship with the host cell that performed aerobic and photosynthetic processes. The bacteria did not harm the host cell and after millions of years of evolution the aerobic bacteria became mitochondria and the photosynthetic bacteria became chloroplasts.