Correct Response: B. Unicellular organisms are diverse and can be classified in many ways. One way is by their primary method of obtaining nutrients and energy. Protozoa are heterotrophic and consume other microbes, algae are autotropic, and fungus-like organisms are heterotrophs that absorb nutrients from dead and decaying organisms. Although there are examples of unicellular algae and fungus-like organisms that consume other microbes in specific situations, this is not their primary method of obtaining nutrients. Movement through fluids using cilia or flagella (A), the ability to aggregate in response to chemical signals (C), and reproduction by binary fission (D) are not unique to protozoa.
