Answer: For decreased chances of rejection
Explanation:
The three higly polymorphic MHC 1 genes in human beings are HLA-A, HLA-B and HLA-C.
These determine the compatibility of the organ or tissue in the recipient's body each by the help of many alleles that segregates in a population.
There are very less chances that a random chosen donor will match the a recipient six allele genotype.
This is the reason parent may be the best donor for organ transplantation or tissue transplantation.
Answer:
the 2nd and 1st statement is correct about frequencies in a population
Answer:
D. The tubes allow water and nutrients to be transported throughout
the plant.
Explanation:
option D supports the description of the cells. The long , vertical tubes transport water and nutrients and are most likely xylem and phloem vessels.
option A is wrong since, chloroplasts inside the cell helps in absorbing sunlight.
option C is also wrong, because water loss is controlled by the stomata in the leaves and they are not long tubes.
option B could possibly be right but option D is better suited.
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.
