Question

Which of the following among a-d is false?

a. gram-negative bacteria: possess endotoxin
b. syncytium formation: cytocidal effect of a virus
c. subunit vaccine: contains live, attenuated organisms
d. a-b toxins: exotoxins
e. possessing a target binding component and a component that disrupts cell function
f. none of a-d are false
g. all are true

Answer 1

The false statement is 'c. subunit vaccine: contains live, attenuated organisms' because a subunit vaccine actually contains only parts of the pathogen and not live microorganisms.

Step-by-step explanation:

The false statement among the options is c. subunit vaccine: contains live, attenuated organisms. A subunit vaccine is one that includes only parts of the target pathogen to stimulate a protective immune response without introducing live pathogens. Gram-negative bacteria indeed possess endotoxin, which is a component of their outer membrane known as Lipopolysaccharide (LPS) and released upon cell death or division.

Syncytium formation having a cytocidal effect of a virus refers to the fusion of infected cells with neighboring cells, leading to a multi-nucleated cell that often ends in cell death. Lastly, A-B toxins, like those produced by Corynebacterium diphtheriae, are exotoxins with a binding component (B) and an activity component (A) that disrupts cell function.