Pretty sure its d... hope this helps
It is a study of ECOSYSTEM and known as ECOLOGY......
Answer:
brown bear
Explanation:
Brown bears have long, intimidating claws. However, since they are not retractable, they are relatively blunt and are usually used for digging. These bears are incredibly strong, able to break the necks of many large prey with one powerful blow. Their thick fur and layer of fat help to insulate them against the extreme cold temperatures of their habitat.
An immunoglobulin molecule of any class with regions symbolized as C or V, H or L, has a light chain made up of one C region and one V region.
The glycoproteins known as immunoglobulins (Ig), often known as antibodies, are created by plasma cells. A number of immunogens, including bacterial proteins, promote B cells' conversion to plasma cells. These cells, which make proteins, are involved in humoral immune reactions to bacteria, viruses, fungi, parasites, cellular antigens, chemicals, and synthetic compounds. Using a B-cell receptor, the immunogen or antigen adheres to the B cells' cell surface (BCR).
As a result, a signal is generated that directs the activation of transcription factors, leading to the manufacture of highly specific antibodies for the immunogen that initially activated the B cell. Furthermore, one B cell clone produces immunoglobulin (specificity). Two light chains and two heavy chains that alternate in a light-heavy-heavy-light pattern make up antibodies, also known as immunoglobulins. Therefore, choice A is the right response.
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Tiny regions at the surfaces of neurons and different cells which are touchy to neurotransmitters or hormones are called receptors.
The required details for receptors in given paragraph
Cellular receptors are proteins both internal a mobileular or on its floor which acquire a sign. In everyday physiology, that is a chemical sign in which a protein-ligand binds a protein receptor. The ligand is a chemical messenger launched with the aid of using one mobileular to sign both itself or a exceptional mobileular. Receptors are proteins that bind to outside messengers to create a chain of downstream consequences that mediate a selected reaction withinside the mobileular. Receptors have a ligand-binding area that acknowledges the particular ligand and the effector area that undergoes conformational modifications to provide a downstream event.
Receptors are available in many types, however they may be divided into categories: intracellular receptors, which can be determined internal of the mobileular (within side the cytoplasm or nucleus), and mobileular floor receptors, which can be determined within side the plasma membrane.
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