I believe it's lactic acid and energy.
Gregor Mendel was an important scientist, considered to be the founder of the science of genetics. His experiments on the crossbreeding of plants and the passing down of favourable traits, led him to establish the laws of Mendelian inheritance. He was using pea plants for his experiments and he was studying seven different pea traits: pea shape and color, pod shape and color, flower color, plant size and position of flowers.
This might represent evolution of a species or the influence of the environment on the expression of a genotype.