Please explain why the following statement is TRUE: A species that lacks variation among its members is more likely to go extinct than a species
with a lot of variation in traits.

A species with genetically identical members would be wholly vulnerable to the same threats and could possibly be wiped out by a single threat. With variation some members of the species might mutate genes that allow them to combat those threats and pass those genes onto their offspring, allowing their entire species to survive.

Fungi is were it belongs