Male vs female cannabis plants (howto)
On a Male cannabis plant you will notice a ball and how it is further from the plant. This is a male preflower. 
On a female cannabis plant you will notice a cone forming which can cause a white hair extend. This is a female preflower. 
Also another great indicator is the stalk texture. Smooth tends to be female and rigid is male. Cheers fam and hope this tip helps you on the garden next time you are popping beans. 👊🙏
interesting
Indeed. If you top after the 5th node the sexing process speeds up a bit too. Cheers growmie.