2.  Root and soil solution

3.  Cell and external solution

4.  All the above

1.  Denitrovibrio

3.  Pseudomonas

4.  Nitrobacter

1.  Locust

3.  Wasp

4.  Bed bug

1.  Nephridia

2.  Malpighian tubules

4.  Flame cells

1.  Ammonotelic

3.  Ureotelic

4.  Aminotelic.

1.  Salmonella typhirsum

2.  Tricinella spiralis

4.  Leishamania donovani

1.  Excretion of salt through respiratory channels

2.  Decrease in respiration during salt absorption

4.  Linking of ion movement with respiratory chain

2.  Cuticle of adult

3.  Cuticle of larva

4.  Salivary glands of the adult.

1.  Corn

3.  Wheat grass

4.  Beets

2.  closed blood vascular system

3.  nephridia

4.  Trachea