Crossing over? That involves the random exchange of chromosomes.
Answer:
the insulin
Explanation:
first we take the gene from human cells and we mix them together with bacterial dna.we place them in a fermentation vessel where it will then multiply. then it create the insulin which we use it for people who suffer from diabete.
(sorry im not that good in englisht)
It is true they do have internal fertilization. This is also one of the reason why it is easy to differentiate between a male or a female shark on birth due ot internal fertilization. <span />
