World of Biology on Instagram: "Real time video of a single sperm, trying very hard to fertilise the egg. The process of reproduction is very interesting. Millions of sperm travelled through innumerable difficulties to reach one egg and then try very hard to fertilise that egg, but the egg is a tough cookie. It only allows sperm to get in and fertilise it and especially only one particular sperm for the process of fertilisation, whether it’s natural or IVF and that is why the process of pregnanc