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.
Answer:
dear user
the answer is option no.1 protons are in the nucleus and ,with electrons and neutrons orbiting the nucleus
The male
human has a sperm cell and the female has an egg cell. The cells from the male
and female that combine to form a zygote are called gametes. The human sperm
and egg cells each contain 23 chromosomes. . A combination of gametes forms a
zygote with 46 chromosomes. The type of cell division that produces gametes
with half the normal chromosome number is the meiosis. Meiosis is the type of
cell division used in sexual reproduction. It will occur in the testes and
ovaries.<span>Chromosomes get
shuffled when eggs and sperm are made. Though most adult cells contain two sets
of chromosomes, sperm and egg cells are different. These special cells have
just one chromosome from each pair. Which chromosome they get from each pair is
random, making each sperm or egg cell unique. There is also a bit of mixing
before the chromosomes are sorted into individual sperm or egg cells.
Chromosomes from each pair in a mother or father, respectively, make contact
and exchange pieces of DNA, creating hybrid chromosomes. </span>
