What are the advantages of organic fertilizer?

What are the advantages of biofertilizers over chemical fertilizers? Give an example for biofertilizer.

In terrestrial organisms like birds and reptiles, internal fertilization take place While some aquatic organisms show external fertilisation What is the disadvantage of external fertilization

Controlled breeding experiments can be carried out using artificial insemination. What are the advantages of this process?

What are the advantages of dihydrogen as a fuel?

What are the advantages of Single Cell proteins?

What are the advantages of tissue culture?