Question

Which of the following is a correct statement about chloroplasts, according to the endosymbiotic theory? a. chloroplasts have the ability to replicate outside the membrane of the parent cell, which gives cells the ability to absorb chloroplasts when needed. b. chloroplasts evolved from amoeba, as observed in professor kwang jeon’s studies. c. fossil records and dna sequencing research show evidence that chloroplasts evolved from mitochondria. d. since the nucleus does not contain chloroplast dna, chloroplasts must be present in a cell for the cell to reproduce more chloroplasts during cell division.

Answer 1

Chloroplasts are organelles that evolved from an endosymbiotic relationship with ancient photosynthetic bacteria, likely cyanobacteria, within early eukaryotic cells. The endosymbiotic theory does not suggest that chloroplasts can replicate outside the parent cell, that they evolved from amoebae, or that they evolved from mitochondria.

Step-by-step explanation:

The correct statement about chloroplasts according to the endosymbiotic theory is not listed in the options provided. According to the endosymbiotic theory, chloroplasts and mitochondria evolved from separate endosymbiotic events involving the uptake of bacteria by ancient eukaryotic cells. Specifically, chloroplasts are the descendants of photosynthetic bacteria, likely cyanobacteria, that were engulfed by early eukaryotic cells. Over time, these bacteria and host cells formed a symbiotic relationship, leading to the bacteria evolving into the organelles known as chloroplasts.

It should be noted that chloroplasts contain their own DNA and ribosomes, which are similar to those found in cyanobacteria. Importantly, chloroplast DNA and mitochondrial DNA show similarities to bacterial DNA, supporting the endosymbiotic origin of these organelles. Chloroplasts also replicate by a process similar to binary fission, reminiscent of bacterial cell division. It is important to clarify that chloroplasts do not have the ability to replicate outside of the parental cell without the pertinent cellular machinery, they did not evolve from amoebae, and they do not have a shared evolutionary path with mitochondria that would suggest they evolved from them.