A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from the airbreathing organ (a simple lung) of an ancestral fish is an example of

What kind of seafood would you expect to have the highest levels of mercury and why? kelp, because they use the sun to photosynthesize on the bottom trophic level. oysters, because they filter feed on plankton on a lower trophic level. small fish, because they eat plankton on a higher trophic level. sharks, because they feed on organisms on a higher trophic level.

When analyzing tree rings, what do scientists assume a thin ring indicates?

How can active reading strategies you? o a. they can you get into better physical shape. o b. they can you read fewer science articles. o c. they can you understand what you read. o d. they can you avoid reading altogether.