Which of these is a group of organs that work together and perform one or more major functions? Organelle
Organ system
Molecule
Tissue please help

Patient has just received an organ transplant which treatment would be most effective in preventing the patient’s body from

Everything that surrounds a particular organism

Choose the best definition of allele. a. one of several possible versions of a gene, which each produce a different phenotype b. an organism that's purebred for a given trait c. the process of fertilizing a plant with pollen from another plant d. a set of genes that are located on the same chromosome and so are tightly linked