Answer:
Answer is 4. Algae incorporated prokaryotic cells that became chloroplasts, but never acquired mitochondria.
Explanation:
It should be noted , that symbiosis or symbiotic relationship is a type of relationship involving two organisms where, one may benefits while the other suffers or both organisms benefit. Symbiosis, may involve one organism living inside or outside the other.
In a situation, whereby one of the organisms involved lived inside the order , is being referred to as endosymbiosis.
This endosymbiosis has been described as probably a means through which the eukaryotic cells got or developed some organelles like chloroplasts and mitochondria.
