The primary function of the respiratory system is to supply blood with oxygen
<span>A(n)PRIMITIVE CHARACTER is one present in the common ancestor and all members of the group
Primitive character is also known as ancestral character in phylogenetics. It is defined as a characteristic that has undergone little change since time immemorial and is inherited from a common ancestor of a clad.
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Protozoa are Eukaryotic organisms, they show animal/plant like behaviors. Bacteria are prokaryotic, very tiny simple single celled organisms with no nucleus or mitochondria.
There are 5 main types of pathogens that can harm other organisms and cause diseases. They are viruses, bacteria, fungi, Protozoa, and worms.
