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.
Natural oils can also help on how to make your eyelashes grow longer. You can moisturize your lashes with one of these natural oils: olive oil, coconut oil, avocado oil, sweet almond oil, linen oil, sesame oil, rosehip oil, argan oil or burdock root oil.