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.
A: It is found in all parts of the castor bean plant but is concentrated in the beans and in the mash left over after the beans are processed to make castor oil. Castor oil, which does not contain ricin, is used in making lubricants, paints and varnishes and is an old-time remedy for constipation.The plants are commonly used in gardens and grow like weeds along riverbanks and stream beds in the southwestern USA.astor oil, which does not contain ricin, is used in making lubricants, paints and varnishes and is an old-time remedy for constipation. The plants are commonly used in gardens and grow like weeds along riverbanks and stream beds in the southwestern USA.