Girasol definition, an opal that reflects light in a bright luminous glow. See more.
Pheophytin or phaeophytin (abbreviated Pheo) is a chemical compound that serves as the first electron carrier intermediate in the electron transfer pathway of Photosystem II (PS II) in plants, and the photosynthetic reaction center (RC P870) found in purple bacteria.
Auxins are hormones involved in plant-cell elongation, apical dominance, and rooting. A well known natural auxin is indoleacetic acid, or IAA which is produced in the apical meristem of the shoot. Developing seeds produce IAA, which stimulates the development of a fleshy fruit.hemotropism is a plant growth response to a chemical. After a flower is pollinated, a pollen tube grows down through the stigma and style and enters the ovule through the micropyle. The growth of the pollen tube in response to chemicals produced by the ovule is an excellent example of chemotropism.