Why do normal t cells, which recognize foreign peptide antigens bound to self mhc molecules, react strongly against the allogeneic mhc molecules of a graft?

How are the cell walls of a plant and fungus different ?

When water freezes, it . contracts expands

Fan egg cell containing the (n+1) number of chromosomes combines with a sperm cell containing the (n) number of chromosomes, what is the result of this union? a) all future somatic cells of the organism will contain the (2n + 1) number of chromosomes. b) all future somatic cells of the organism will contain the (2n - 1) number of chromosomes. c) only certain somatic cells of the organism will contain the (2n + 1) number of chromosomes. d) all future somatic cells of the organism will contain the normal diploid number of chromosomes.