Final answer:
The statement best describes the endosymbiotic theory, which proposes that mitochondria and chloroplasts arose as a result of prokaryotic cells establishing a symbiotic relationship with eukaryotes.
Step-by-step explanation:
The statement that some individual prokaryotes were responsible for transferring the bacteria that caused mitochondrial development to the new eukaryotes, whereas other species transferred the bacteria that gave rise to chloroplasts, best describes the endosymbiotic theory. According to this theory, mitochondria and chloroplasts in eukaryotic cells originated from prokaryotic cells that were engulfed by early eukaryotes and formed a symbiotic relationship with them.
This theory is supported by genetic evidence, such as the similarity between mitochondrial/chloroplast DNA and bacterial DNA, as well as the structural similarities between mitochondrial/chloroplast ribosomes and bacterial ribosomes.
The endosymbiotic theory suggests that the ancestors of modern eukaryotes engulfed these bacteria, which then became permanent and beneficial parts of the eukaryotic cells. Over time, the engulfed bacteria evolved into organelles, specifically mitochondria and chloroplasts. This theory is widely accepted due to genetic evidence from DNA sequencing, which shows that mitochondrial DNA and chloroplast DNA share a close resemblance to bacterial DNA, both in sequence and chromosome structure.