Answer: False
Explanation:
Protozoans are not the organism that fix nitrogen for the plants. The organism that fix nitrogen to convert it into a form which can be used by plants are known as diazotrophs.
These are bacteria and archae that fix nitrogen gas found in the atmosphere into more usable form such as ammonia.
These organism can grow without any external source of fixed nitrogen. Example: Rhizobia and azospirillium.
Answer:
A cell carries out all the processes of the body which includes producing energy and storing it, making proteins which are molecules which have roles in metabolism, transportation of other molecules and DNA replication.
The role of the nucleolus is to make the monomer of of ribosomes, and ribosomes are used in mRNA to make protein. Therefore the nucleolus plays a major role in the process of making proteins for our body. <span />