All living creatures are classified into systems and sub-systems based on their similar characteristics. They are divided from bigger groups into smaller groups based on the detail of their similarities i.e. how they look, move, reproduce and how they relate to each other. A practical way of understanding the classification of living organisms is that organisms are linked to other similar organisms via family trees. The classification of all living creatures includes at least four levels: order, families, genus and species.
Answer:Sclerenchyma
Explanation:Sclerenchyma is thick walled dead lignified cells, they are hard and elastic. The sclerenchyma cells are divided into two groups namely fibers and sclereids. Sclerenchymatous fibers are branched/unbranched, long, hard, pointed cells with tapering ends, thick walls, and narrow lumen.
The answer is; cell surface receptors that are recognized as antigens by the recipient's immune system.
Therefore the organ is attacked as a foreign substance . This is why organ transplants are given by the closest family member to reduce the antigen variability that causes transplant rejection. Tissue typing is done to ensure that the organ or tissue is as similar as possible to the tissues of the recipient.
