What organism is the first step in food chain/web? what organism is normally first step in aquatic food chain/web? \?

Sea stars, sea urchins, sand dollars, and brittle stars are all memeber of a group, what is the common name of the group they are all in

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.

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above