When a stimulus is produced it signifies the production of sensation in the sensory organs. This sensation through the sensory organs (eyes, ears, nose, skin and tongue) is sent to the sensory nerve connected to these sense organs. These sensory nerves send nerve impulses through the nerve fiber to the spinal cord. From the spinal cord the nerve impulse is transferred to motor nerves.
The motor nerve then sends response to the stimulus though the same path to the region from which stimulus was received and thus the body responds through muscular activity. Such as removal of heat from the heated object if heated sensations were received.
A DNA replication is when you replicate someone's DNA, which is not possible yet, because everyone's DNA strand is different. But the growth of an organism is just the reproduction of cells growing into fully functioning ones.
It would be #2 because it dosent have those specific antigens to defend the pathogen.
Answer:
Adaptations of the alveoli:
Moist walls - gases dissolve in the moisture helping them to pass across the gas exchange surface. Permeable walls - allow gases to pass through. Extensive blood supply - ensuring oxygen rich blood is taken away from the lungs and carbon dioxide rich blood is taken to the lungs.
