Answer:
Explanation:
Organisms have different forms of circulatory systems. Humans have a closed circulatory system, while many mollusks and other invertebrates have an open system. In a closed circulatory system, blood is enclosed within blood vessels.
Conduction, convection, and radiation
Answer:
Some examples of decomposers include bacteria, fungi, and some insects. If decomposers disappeared from a forest ecosystem, wastes as well as the remains of the dead organisms would pile up, and producers (plants) would not have enough nutrients.
Darwin called the ability of an organism to survive and reproduce in its environment fitness.
Some organisms were fit to do all of these things, whereas others were not.
