Paulinella chromatophora is one of the few cercozoans that is autotrophic, carry
ID: 24948 • Letter: P
Question
Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated "cyanelles." The cyanelles are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants.If true, which of the following would be most important in determining whether P. chromatophora's cyanelle is still an endosymbiont, or is an organelle, as the term cyanelle implies?
A) If P. chromatophora is less fit without its cyanelle than with it.
B) If there is ongoing metabolic cooperation between the cyanelle and the host cercozoan.
C)If the cyanelle is less fit without the host cercozoan than with it.
D)If there has been movement of genes from the cyanelle genome to the nuclear genome, such that these genes are no longer present in the cyanelle genome.
E)If the magnesium-containing porphyrin ring in the cyanelle's chlorophyll molecules is built by the cyanelle, whereas the organic portion of the chlorophyll molecules is built by the host cercozoan.
Explanation / Answer
C)If the cyanelle is less fit without the host cercozoan than with it.