Plant research has often been done with plants. In genetics, the breeding of pea plants allowed Gregor Mendel to derive the basic laws governing inheritance, and examination of chromosomes in maize allowed Barbara McClintock to demonstrate their connection to inherited traits. The plant "Arabidopsis thaliana" is used in laboratories as a model organism to understand how genes control the growth and development of plant structures. NASA predicts that space stations or space colonies will one day rely on plants for life support. Ancient trees are revered and many are famous. Tree rings themselves are an important method of dating in archeology,
Classical genetics as molecular genetics. At the base of classical genetics is the concept of a gene, the hereditary factor tied to a particular simple feature (or character). The set of genes for one or more characters possessed by an individual is the genotype. A diploid individual often has two alleles for the determination of a character. Classical genetics is the part of genetics that is solely about the method in which genetic traits are transmitted via the acts of reproduction. Genetics is, generally, the study of genes, genetic variation, and heredity. The process by which characteristics are passed down from parents