Which of the following two compounds play main role in maintaining the osmolarity gradient in medulla?

Which of the following plays a major role in maintaining a osmolarity gradient in medula of kidney?

Which of the following plays a major role in maintaining a osmolarity gradient in medula of kidney?

Which of the following hormones play a role in lactation?

Which of the following structures play a significant role in maintaining osmolarity in mammals?

Which of the following structures play a significant role in maintaining osmolarity in mammals?

Which of the following does not play a role in blood coagulation

Which of the following does not play a role in blood coagulation

Which of the following compounds of C plays a vital role in the carbon cycle?

Which of the following microorganisms play important roles in maintaining the balance of nitrogen gas in the atmosphere?

Which of the following factors play a role in primary productivity?