In cladistic analysis, similar genes that appear in dissimilar organisms, indicate that they share
a common

Common ancestor is an ancestral organism that two or more descendant lineages have in common. If organisms are not similar, but still have similar genes, that indicates that they share the common ancestor. The more basic the common genes are, their common ancestor is more close to the last universal common ancestor (LUCA).

answer: - b cells

explanation: -

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.

allowed for the prediction of the properties of missing elements.