Chapter 7, Problem 2TYK

What are three attributes of mitochondria and chloroplasts that suggest they were once free-living bacteria?

Summary Introduction

To review:

The three attributes of mitochondria and chloroplasts that suggest they were once free-living bacteria.

Introduction:

Mitochondria and chloroplast are two different cell organelles. Mitochondria functions in the production of energy in the form of ATP (adenosine triphosphate) and the function of the chloroplast is to convert solar light energy into sugar.

Explanation of Solution

Mitochondria and chloroplast are the eukaryotic organelles, which are similar to the bacterial cell.

1. Similar to the bacterial genome, the mitochondria and chloroplast contain their own genetic material. The genetic material is in the form of small, circular chromosomes. The extra chromosomal material, that is, the plasmid, is also present in the mitochondria and chloroplast, similar to the bacteria. Since these organelles possess their own genetic material, they synthesize their own protein.

2. The mitochondria and chloroplast produce their own ribosomes. The protein production pattern in these organelles is also similar to that in bacteria. It starts with the N-formylmethionine amino acid.

3. The mitochondria and chloroplast make their own copies by the process of binary fission, which is same as the bacterial cell division. Mitochondria and chloroplast also divide and give rise to identical organelles like bacteria.

These attributes of the mitochondria and chloroplast suggest that these organelles were once free-living bacteria.

Conclusion

The three attributes of mitochondria and chloroplasts that suggest they were once free-living bacteria are that they both produce their own ribosomes as well as small, circular chromosomes, and they both divide independently by binary fission like bacteria.