Question

multiple choice question
martinus beijerinck is known to have used very precise filters to remove bacterial cells and reasoned that smaller agents, called ______, were responsible for infections.

• viruses
• worms (parasites)
• prions
• viroids

Explanation:

Martinus Beijerinck's filter experiments showed that infectious agents smaller than bacteria (which passed through the filters) caused infections; these were the first recognized viruses. Worms are much larger than bacteria, prions and viroids were identified later and not the focus of Beijerinck's key filter-based reasoning.

Answer:

A. viruses