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.
Itâs thought that the practice of using castor oil to induce labor dates back to the Egyptians. Even today, it remains an old wivesâ tale for jump-starting labor. Hereâs what you need to know about the doâs and donâts of using castor oil to induce labor. What is castor oil? Castor oil is derived from the seeds of a plant called Ricinus communis. Itâs native to India. The chemical composition of castor oil is unusual because itâs comprised mainly of ricinoleic acid, a fatty acid. Itâs this high concentration that likely gives castor oil the reputation for having various healing properties.