<human>:  Who came up with the quark model?
<bot>: The quark model was proposed by Murray Gell-Mann in 1964. The model is a model of elementary particles, based on the assumption that all matter is made up of smaller particles called quarks. The quarks are the smallest particles in the standard model, and are found to be the building blocks of protons and neutrons. The quarks are named after the first letters of the names of their respective colors: red, blue, green, and yellow.