Research has found that a single area of the brain can have multople functions. which brain area plays a role in speech and also lets us know when a musical note is off key

Answer

-Broca's area

Explanation;

Broca's area is a region in the frontal lobe of the dominant hemisphere, usually the left, of the hominid brain with functions linked to speech production.

-Aphasia is the loss of the ability to understand speech or communicate using language. It can occur when areas of the brain responsible for language become damaged. Broca's aphasia results from damage of the Broca's area, which is located in the frontal lobe, usually on the left side.

c. heat from the poles back down towards the equator.

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.