Question

2/10
what are homologous structures?
structures with identical functions across species.
structures that are unique to each species.
structures with similar ancestry but different functions.

Explanation:

Homologous structures are defined by having a common evolutionary origin (similar ancestry) but can have different functions in different species. For example, the forelimbs of humans, bats, and whales have a similar bone - structure (indicating a common ancestor) but are used for different purposes (grasping, flying, swimming). The first option about identical functions across species is incorrect as homologous structures don't necessarily have the same function. The second option about being unique to each species is also wrong because homologous structures imply a shared ancestry.

Answer:

Structures with similar ancestry but different functions.