Which statement is least likely to support the endosymbiotic theory? .
a. mitochondria and chloroplasts reproduce independently from the cell..
b. mitochondria and chloroplasts contain their own ribosomes..
c. mitochondria and chloroplasts have dna that resembles bacterial dna..
d. mitochondria and chloroplasts are much larger than prokaryotic cells.

The answer is option D. Mitochondria and chloroplasts are much larger than prokaryotic cells.

According to endosymbiotic theory, cell organelles like mitochondria and chloroplast were phagocytosed (engulfed) by eukaryotic cells by the process of endocytosis. The reason why the DNA of mitochondria and chloroplast resembles to the bacterial DNA is because prior to their phagocytosis into a eukaryotic cell, they existed as an independent prokaryotic organism. Blue green algae (cyanobacteria) which evolved as chloroplast is able to do photosynthesis whereas an another prokaryote named Rickettsia prowazekii was endocytosed by eukaryotic cell to become mitochondria. Mitochondria and chloroplast both reproduce through binary fission just like Rickettsia prowazekii and blue green algae (cyanobacteria).  Also, mitochondria and chloroplast both have their own  70 'S' ribosomes just like prokaryotes while eukaryotic cell in which they reside have 80 'S' ribosomes. So, option a, b and c strongly support endosymbiotic theory. But, mitochondria and chloroplast are bigger in size than Rickettsia prowazekii and blue green algae (cyanobacteria) respectively which should not be the case if they actually existed as Rickettsia prowazekii and blue green algae (cyanobacteria) initially. That is why statement d. least supports the endosymbiotic theory.

Mitochondria and chloroplasts are much larger than prokaryotic cells. This statement is less likely to support the endosymbiotic theory.

Further Explanation:

Endosymbiotic theory describes the origin of chloroplasts and mitochondria. On the evolutionary basis, mitochondria and chloroplast both originated due to endosymbiotic theory. The relatives of parasite Rickettsia and purple sulfur bacteria were engulfed by the eukaryotic cell to give rise to mitochondria.The red and green algae engulfed cyanobacteria for obtaining the chloroplast.The brown algae engulfed the red algae to obtain the chloroplast. Mitochondria and chloroplast are membrane-bound organelles responsible for the generation of energy. Both have complex internal organizations; a matrix in mitochondria is considered analogous to the stroma of the chloroplast.

The genetic material in both organelles is circular, as found in prokaryotes. The chloroplast performs the function of photosynthesis during which they generate a pH gradient to synthesize ATP. The mitochondria perform respiration during which the electron transport chain generates the gradient of hydrogen ions concentration to synthesize ATP molecules.

Learn More:

1. Learn more about the effects of vigorous exercise on cardiorespiratory system

2. Learn more about the structure of epithelium and connective tissue

3. Learn more about the secondary function of the lymphatic system

Answer Details:

Grade: High School

Subjects: Biology

Chapter: Cellular Respiration

Keywords:

Endosymbiotic theory, rickettsia, generation, mitochondria, chloroplast, analogous, stroma, ATP, prokaryotes, bacteria, eukaryotes, red, green, algae.

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.