Question

multiple choice question
when does positive chemotaxis occur?
o when damaged cells release chemicals that attract leukocytes
o when damaged cells convert fibrinogen to fibrin
o when damaged cells release chemicals that activate platelets

Explanation:

Positive chemotaxis is the movement of cells towards a chemical stimulus. Leukocytes are attracted to chemicals released by damaged cells, which is an example of positive chemotaxis. Converting fibrinogen to fibrin is part of blood - clotting and not related to chemotaxis. Activating platelets by damaged - cell chemicals is also not chemotaxis.

Answer:

When damaged cells release chemicals that attract leukocytes