Which structure starts at the brain and goes down the back? a) the spinal cord b) the brain stem c) the cerebral cortex d) the limbic system

The spinal cord.

Explanation:

The brain and the spinal cord are attached and the spinal cord from the head goes down to back of the body.

The spinal cord acts as the framework for the backbone and helps in performing various functions of the body. The spinal cord connects the higher centers of the body to the various parts of the body by the help of autonomic and somatic veins of the peripheral nervous system.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."

the answer to your question is tooth decay.