Answer:
<em>Involuntary </em><em>physiologic</em><em> </em><em>processes</em>
Each sieve tube element is normally associated with one or more nucleated companion cells, to which they are connected by plasnodesmata (channels between the cells). Each companion cell is derived from the same mother cell as its associated sieve tube member. Sieve tube members have no cell nucleus, ribosomes, or vacues. Thus, they depend on companion cells to provide proteins, ATP, and signalling molecules
Answer:
Allergens differ from antigens because *they do no stimulate the immune system resulting in the production of leukocytes rather than the stmulate the IgE antibodies*
Explanation:
Allergen and antigen are both foreign substances that can cause certain disorders to animals, but there is some difference between them in terms of their nature and the diseases caused by them. An allergen is a nonparasitic foreign substance that can cause certain immune reactions in the body when it enters the body. Whereas, an antigen is a foreign substance that can trigger the immune system to produce a specific immune response. This immune response leads to produce antibodies that can neutralize or destroy the foreign substances that entered the body.
Allergens can produce Systemic Allergic Response. Allergens stimulate the IgE antibodies by binding to them on the mast cells and causing the mast cells to rupture and release histamine, serotonin, and heparin, initiating inflammatory response.
C. nucleic acids (consisting of genes which encode for specific proteins to be synthetized)
