Which are products of nitrogen fixation?

Nitrogen fixation is the process by which atmospheric nitrogen is converted either by a natural or an industrial means to a form of nitrogen such as ammonia. In nature, most nitrogen is harvested from the atmosphere by microorganisms (see above) to form ammonia, nitrites, and nitrates that can be used by plants.

Explanation:

"do a testcross with a homozygous recessive plant."

common management practices in dairy and poultry farming are: (i) proper shelter facilities and their regular cleaning. (ii) some basic hygienic conditions such as clean water, nutritious food, etc. (iii) animals are kept in spacious, airy, and ventilated place.