I need help please and thank you?

The influenza virus cause the flu, but not other diseases. why?

In a cross between individuals of a species of tropical fish, all of the male offspring have long tail fins, and none of the females possess the trait. mating two of the f1 fish fails to produce females with the trait. explain the inheritance pattern of the trait.

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?