Firstly they are not membranes and they are villi's which increase the surface area during digestion
Answer:
The correct answer is option D. A and C.
Explanation:
Lymphoid tissue is the body part that is an essential part of the immune system that provides immune response against different infection or pathogens and protects from these foreign bodies. These tissues are present in all over the body that includes spleen, adenoids, tonsils, lymph nodes and other parts.
Lymphoid tissues or organs are the sites of the proliferation of the macrophages and lymphocytes. These structures also assist in furnishing surveillance points for lymphocytes and macrophages.
Thus, the correct answer is option D. A and C.
<span>Central nervous system
Sympathetic nervous system
The neuron, a cell that composes the nervous system. For example a brain, an organ composed of thousands of neural fibers and glial cells that performs many important organismic functions. </span>
<span>Neurons are specialised cells that have dendrites, axons and terminal buttons that sends and receives stimuli from the environment and transduces it into a meaningful information and understand the complexities which the brain now functions.<span>
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<span>The smell of Danger.
Researchers have discovered a single compound found in high concentrations in the urine of carnivores that triggers an instinctual avoidance response in mice and rats. This is the first time that scientists have identified a chemical tag that would let rodents sense carnivores in general from a safe distance.</span>