Why do you think a "one-way" digestive tract is more efficient?

The location of the stomach is the diaprham

What is the next step in muscle contraction after the actin changes shape? (apex)

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.