Question

in a biology class, a student is creating a model of a eukaryotic cell. the student decides to add a small, rod - shaped structure to the cell that has its own circular dna, double membrane, and ribosomes that are smaller than those found in the host cells cytoplasm. the student correctly labels this structure as a mitochondrion. based on this model and your knowledge of the endosymbiotic theory, which of the following is the most accurate statement about the origin of the mitochondrion? the mitochondrion formed independently as a new organelle and has no evolutionary relationship to other cell types. the mitochondrion evolved from a prokaryotic cell that was engulfed by an ancestral host cell and formed a mutually beneficial relationship. the mitochondrion developed as a result of a mutation in the host cells cytoplasm that led to the formation of a new organelle. the mitochondrion originated from the host cells nucleus, which was modified to specialize in cellular respiration.

Explanation:

The endosymbiotic theory posits that mitochondria originated from prokaryotic cells engulfed by an ancestral host cell, forming a mutually - beneficial relationship. Mitochondria have their own DNA, which supports the idea that they were once independent organisms.

Answer:

The mitochondrion evolved from a prokaryotic cell that was engulfed by an ancestral host cell and formed a mutually beneficial relationship.