Answer:
When petting a dog, mechanoreceptors in the skin of your hand send signals to the sensory neuron. The sensory neuron connects to your spinal cord and through your brain.
Explanation:
Earth is a beautiful planet that revolves around a star called Sun, which is located in one of the arms of our Milky Way Galaxy. It is the only planet known to support life in the Solar System. Humans are the most intelligent civilization on this planet. It's blue when seen from space. Recently, Earth 29 spacecraft was able to land on this planet, after 28 unsuccessful landings of Earth series of spacecrafts. We were able to learn many things about humans, most important of these was the most spoken language of them, which they call English. According to experts, humans are not yet ready to know about our existence. It can take about 1 or 2 more centuries, until they are ready to know about us.
Answer:
Adaptive immune defense system consists of lymphocytes like B-lymphocytes and T- lymphocytes. B-lymphocytes provides humoral immunity while T- lymphocytes provide cell-mediated immunity to the body.
99% of lymphocytes circulate freely in the blood and lymph. B lymphocytes differentiate into plasma B cells and B memory cells when interact with antigen presented by T helper cells.
Then plasma cells secrete antibodies in the circulation which binds to extracellular antigens through antigen-binding site. Then the bounded antigen is recognized by receptors present on phagocytic cells. This receptor binds the Fc region of antigen bounded antibody and destroy the antigen by phagocytosis.
I think the answer is A because direct sunlight causes dyes in clothes to fade quietly.
