During prophase I, each of the homologous pairs of chromosomes can be seen as bivalent or as a grouping of two chromosomes said to be sister chromatids. The site at which the crossing over occurs on the sister chromatids is known as the chiasma. Prophase I is the longest phase during the meiosis process and takes up to 90 percent of the total time of cell division.
Castor beans are pressed to extract castor oil which is used for medicinal purposes. Ricin (a toxic substance present in the plant) does not partition into the oil because it is water-soluble, therefore, castor oil does not contain ricin, provided that no cross-contamination occurred during its production.icin (a toxic substance present in the plant) does not partition into the oil because it is water-soluble, therefore, castor oil does not contain ricin, provided that no cross-contamination occurred during its production.
Castor oil is used as a laxative for constipation, to start labor in pregnancy, and to start the flow of breast milk. Some people apply castor seed paste to the skin as a poultice for inflammatory skin disorders, boils, carbuncles, pockets of infection (abscesses), inflammation of the middle ear, and migraine headaches.Castor oil is used topically to soften skin, bunions and corns; and to dissolve cysts, growths, and warts.ome people apply castor seed paste to the skin as a poultice for inflammatory skin disorders, boils, carbuncles, pockets of infection (abscesses), inflammation of the middle ear, and migraine headaches. Castor oil is used topically to soften skin, bunions and corns; and to dissolve cysts, growths, and warts.