I believe the positive control receives a treatment with a known response, so that this positive response can be compared to the unknown response of the treatment. This is used in electrophoresis to compare the DNA strands to the DNA standard. The negative control is used when no response is expected, which is also used in the process of electrophoresis. Electrophoresis is a technique used in laboratories in order to separate macromolecules based on size. It applies a negative charge so proteins move towards a positive charge. It is sued for the analysis of both DNA and RNA.
Answer:
External auditory meatus
Explanation:
The pinna leads into the external auditory meatus which is a tube that directs sound waves to the tympanic membrane. The tube is lined with hairs which trap solid particles that may enter the ear. It is also lined by wax secreting cells whose function is to secrete wax that traps dust and prevents entry of solid particles. The wax also maintains the flexibility of the eardrum.
