Transgenic Brassica napus seeds are being used to produce the anticoagulant hirudin. $\mathrm{Bt}$ in "Bt Cotton" stands for Bacillus thuringiensis. This is naturally occurring soil bacterium. Classical plant breeding involves crossing or hybridisation of purelines, followed by artificial selection to produce plants with desirable traits whereas somatic hybridisation involves fusion of protoplast of two cells. Golden rice is a transgenic variety of rice rich in $\beta$-carotene (provitamin A - inactive state of vitamin A).