Choose the word that best completes this sentence. exist in the ground, air, and bodies of most living things but do not need a host organism to live and multiply. a. bacteria b. infectious diseases c. pathogens d. viruses

Bacteria

Explanation:

Bacteria are microscopic, single celled organism that can live in normal conditions as well as it can thrive in the diverse environments.

These organism live in soil, air, water, ocean, and even inside the gut of human beings and other organism.

It can survive without host or even survive inside the host. Bacteria are useful and harmful as well.

It can help in food processing and can also cause harmful diseases. It is found everywhere and hence called as omnipresent.

several tissues working together form an organ, and several organs together make up an organisms.

the group of cell that carries out special jobs are tissue.