The endosymbiont theory proposes that eukaryotes evolved from a symbiosis between a prokaryote and a protocell.
a. true
b. false

a. True

As many researchers hypothesize that the old single-celled organism or the origin of the complex-celled organisms came from the endosymbiosis of the mitochrondrion organism and the prokaryotic cell. It has been said that mitochondria was an independent organism which then to have been evovled itself after planting itself inside a prokaryotic cell which aided cellular respiration and production of ATP (Adenosine Triphosphate). This then aided the prokaryotic cell to be more sophisticated and caused another change from having without a true nucleus to a eukaryotic cell with a nucleus and embedded DNA.  

The return of the wolf to yellowstone national park will probably affect the bird population to some degree, not significantly. while wolves will hunt birds when necessary, they prefer to hunt larger prey. the bird population will most likely only be affected when hunting is scarce for the wolves. birds of prey will also probably not be affected as much as other birds who spend more time on the ground hunting for food as the tend to spend more time in the air or in trees since they do not need to stay on the ground for long due to the nature of the way they hunt.