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 contains an extremely high amount of a rare and unusual fatty acid called ricinoleic acid. Ricinoleic acid is an unsaturated fatty acid which is only found in castor oil and in a group of fungi called ergot.This fatty acid is highly beneficial to health and its effects on humans will be discussed later on.astor oil is a thick, golden liquid obtained from the seeds of the castor plant (also called castor beans) that has no scent or odour. Note that the castor seeds are only nominally called beans and are not in fact, true beans.