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.
Castor oil- This natural oil must be thoroughly massaged on the thin eyebrows before hitting the bed for catching sleep. The oil counters medical conditions like eczema which hampers hair growth in eyebrows. Massaging the brows with this oil triggers the hair follicles to renew the hair growth.