The endosymbiotic theory to explain the origin of which structures?
a) mitochondria
b) ribosomes
c) nuclei
d) cell membranes

The correct answer would be A) mitochondria.

Endosymbiotic theory states that the eukaryotic cells evolved by the symbiosis of unicellular prokaryotic cells such as bacteria and archaea.

According to this theory, the animal cells and plant cells are believed to possess mitochondria and chloroplast respectively through endosymbiosis.

Mitochondria appear or are related to Rickettsiales and proteobacteria, and chloroplasts are believed to evolve from cyanobacteria, a nitrogen-fixing bacteria.

Endosymbiotic theory explains that the eukaryotes and the prokaryotes have the same ancestor. It explains their theory on the basis of mitochondria and chloroplast structure.

Further Explanation:

The endosymbiotic theory describes that life emerges on earth nearly around four billion years ago. It also explains that prokaryotes, as well as eukaryotes,evolved from the same ancestor. There is evidence that the first eukaryote might be similar toan amoeba that engulfs their food by phagocytosis. It is stated that the organisms (amoeba) may have ingested the prokaryotic cells that may have survived within the organism that leads toa symbiotic relationship.

The mitochondria were formed or developed when the organism engulfs the microbe which is capable of cellular or aerobic respiration. The chloroplast wasalso developed from the same process. They lose their cell wall as well asa certain part of the DNA because there was no use of it. Mitochondria and chloroplast are not able to grow outside the host cell. They have their own DNA that is circular in structure and they also possess their own ribosomes.

Learn More:

1. Learn more about the treatment of eukaryotic cell with a drug

2. Learn more about the proteins synthesis in a cell

3. Learn more about an exchange of gases by blood cells

Answer Details:

Grade: High school

Subject: Biology

Chapter: Cell and cell structure

Keywords:

Endosymbiotic, earth, prokaryotes, ancestor, amoeba, symbiotic, phagocytosis, mitochondria, chloroplast, bacteria, photosynthesis, ribosomes.