Best Answer: Crossing-over is another name for recombination or physical exchange of equal pieces of adjacent non-sister chromatids. When crossing-over occurs chromatids break and may be reattached to a different homologous chromosome. This occurs during Meiosis 1 / Prophase 1. Synapsis occurs when homologous chromosomes form tetrads and crossing-over or recombination takes place.
The best time to apply castor oil is at night, preferably couple of hours before bed time. While it is perfectly fine to use them during day time, there is a big advantage in applying them at night as this allows more time to saturate and start the process which aids in growing eyelashes.
However, the hair does not always completely grow back. If this is the case, you can use certain natural oils to stimulate hair growth in your eyebrows. Castor oil is a natural oil that makes eyebrows grow. Not only does it make the eyebrows grow quickly, it also makes the hair that grows in much thicker. This is an easy remedy to use, as Castor oil can be found in most drugstores or health food stores. To use the oil, just apply a few drops to your eyebrows at a minimum of twice per day.