Please help i’ll give you brainlist

Name the following: (a) category of pathogen that causes diseases, like common cold and mumps. (b) the microorganism that requires a host to produce.

What feature of cell theory is best demonstrated in the image

How can a geological time scale best be reconstructed? a) comparing vestigial structures in living species b) comparing homologous structures in living species c) examining homologous structures in fossil remains d) examining the written records of scientists from past cultures