
Last option: Preserve an ecosystem

• The establishment of a bird reservation is a way to preserve an ecosystem because reservation provides suitable environment to organism. A healthy ecosystem means large number of biodiversity.
The correct answer is chloroplast. If an organism has chloroplasts then it will be an autotroph because it will be able to make its own food by the means of photosynthesis. This is common for plants but there are some bacteria that can photosynthesize as well. If you don't have them you have to feed on other organisms that have energy for you.
More competition for food, because there wont be enough to go around
A possible reason for the transition of algae from unicellularity
to multicellularity would be the evolution of multicellularity allowed algae to
develop traits that keep them close to the land and thus a source of nutrients.
The correct answer between all the choices given is the last choice. I
am hoping that this answer has satisfied your query and it will be able to help
you in your endeavor, and if you would like, feel free to ask another question.