Which of the following statements are fundamental to the clonal-selection theory of how the adaptive immune system functions? I)
Each lymphocyte has a unique membrane receptor that recognizes one antigen. II) When the lymphocyte binds an antigen, it is activated and begins dividing to form many identical copies of itself. III) Cloned lymphocytes have slight differences and are selected by the spleen for removal if they do not bind an antigen. IV) Cloned cells descend from an activated lymphocyte and persist even after the pathogen is eliminated.
Which of the following statements are fundamental to the clonal-selection theory of how the adaptive immune system functions? I) Each lymphocyte has a unique membrane receptor that recognizes one antigen. II) When the lymphocyte binds an antigen, it is activated and begins dividing to form many identical copies of itself. III) Cloned lymphocytes have slight differences and are selected by the spleen for removal if they do not bind an antigen. IV) Cloned cells descend from an activated lymphocyte and persist even after the pathogen is eliminated.
A. only I and III
B. only II and IV
C. only I, II, and IV
D. only II, III, and IV
Answer:
C. only I, II, and IV
Explanation:
Lymphocytes have specific membrane receptors. These receptors serve as binding sites for specific antigens. Binding of the antigen to these surface receptors triggers the propagation of lymphocytes which in turn form effector cells and the memory cells.
For example, the activated B lymphocytes divide into plasma cells and memory cells. The plasma cells divide and form a group of antibodies all of which have receptors for the antigen recognized by the parent B lymphocyte. The memory cells live in the body and begin the immune response when the same antigen ever enters. T lymphocytes also divide and form effector cells (active helper T cells and cytotoxic cells) and memory T cells.
These preparations are called Vaccines. A vaccine is a biological preparation that provides active acquired immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing micro-organism and is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins.
The corpus callosum associates the left half of the cerebrum to the correct side, each side being known as a side of the equator. The association permits data to go between the two parts.
Corpus callosum is Latin for "extreme body," and the corpus callosum is the biggest connective pathway in the mind, being comprised of in excess of 200 million nerve strands.
Occasionally, an individual will be conceived without a corpus callosum. This is known as agenesis of the corpus callosum, and it causes a wide assortment of physical and social indications.
Each side of the mind controls development and feeling in the contrary portion of the body. The halves of the globe additionally process data, for example, language.
In this manner, physical coordination and taking in complex data requires the two sides of the cerebrum to cooperate.
ATP fuels the primary active transport pump for Sodium and Potassium. The pump maintains a positive voltage on the exterior of the cell and negative on the interior.
