<span>"Crista galli, </span>a superior projection on the ethmoid bone, attaches to the dura mater and secures the brain within the skull."
Crista galli is a vertical projection of the ethmoid bond where the falx cerebri attaches. The falx cerebri is a part of the dura mater that makes the division between the right and left hemispheres holding it into place.
<span>The endosymbiotic theory deals with the origins of mitochondria and chloroplasts, two eukaryotic organelles that have bacteria characteristics. Mitochondria and chloroplasts are believed to have developed from symbiotic bacteria, specifically alpha-proteobacteria and cyanobacteria, respectively.</span>
