Answer:
B) oaks and other sexually reproducing, extant (currently living) trees
Explanation:
The biological species concept defines the species on the basis of their reproductive isolation. It states that when individuals are able to interbreed to produce fertile and viable progeny, they belong to the same species. The members of different biological species cannot interbreed. If they interbreed, either pre-zygotic or post-zygotic isolation mechanisms do not allow the production of fertile progeny.
Therefore, the biological species concept can be applied to the organisms that are able to reproduce sexually. The asexually reproducing organisms would not exhibit any reproductive isolation which is a key criterion to group organisms under different species. Among the given examples, biological species concept can be applied to the sexually reproducing extant trees such as oak.
Since we cannot deduce the reproductive isolation in sexually reproducing extinct species, the concept is not useful for dinosaurs which are extinct now.
Answer: Nitrogen
Explanation: just trust me
Considering the answers;
A. are still sibling species
B. shared a common ancestor more recently with each other than either did with the other two species
C.May merge into a single species if their hybrids remain fertile over the course of many generations.
D. A and B only
E. A, B, and C
The answer will be E.
If no other species can hybridize, then species W and Y are still sibling species, shared a common ancestor more recently with each other than either did with the other two species and also may merge into a single species if their hybrids remain fertile over the course of many generations.
