Which of the following is not true concerning the zebra mussel in the united states?
a. it was introduced accidentally.
b. it was first introduced in the great lakes.
c. it is still spreading throughout the united states.
d. it can be eliminated from a river with minimal effort.

The correct answer is (d) it can eliminated from a river with minimal effort.

Zebra mussels are small mussels that live in freshwater. They are native to lakes of southern Russia and Ukraine. Accidentally, they were introduced into many other countries worldwide. They were first introduced in the great lakes. Then it started spreading throughout the united sates.They become problems  because they were not removed easily from the lakes. They started filtering water and eating the plankton. As they eat a lot of plankton, this started a competition between the zebra mussel and fishes of lake. They also clog pipes and as a result of this water cannot flow through the pipes.

a motor homunculus represents a map of brain areas dedicated to motor processing for different anatomical divisions of the body.

homunculus represents the importance of various parts of your body as seen by your brain. as a result, they take up a lot of brain space. although the cortical homunculus is a curiosity, penfield's work in mapping the brain's relationship to the body was invaluable.