It is oxygen. Hope this helps
<h2>Urea </h2>
Explanation:
Urea is a small nitrogenous compound which is the main end product of protein catabolism in mammals
- Urea is a nitrogen-containing substance normally cleared from the blood by the kidney into the urine
- It is made predominantly in the liver from ammonia and bicarbonate and is one of the main components of urine
- The rate of synthesis varies from 300 to 600 mmol/day depending on the protein intake
- All of this urea eventually finds its way into the urine
- Because urea makes up a large part of the obligatory solute excretion, its osmotic pressure requires significant volumes of water to carry the urea
- Urea passively crosses biological membranes, but its permeability is low because of its low solubility in the lipid bilayer
- Some cells speed up this process through urea transporters, which move urea by facilitated diffusion
- Urea is passively reabsorbed in the proximal tubule, but its route of transport is not clear
- Urea transporters have not yet been identified for the proximal tubule
Answer:
B
Explanation:
a base is a negatively charged anion capable of reacting with anion species such as H ions
B. Abiotic
Explanation:
The role of flowing water in this ecosystem is abiotic.
- Abiotic factors in an ecosystem are the non-living factors that shapes an ecosystem.
- An ecosystem is made up of both living and non-living components.
- The action of running water is termed erosion and it shapes the land form as seen in the badland.
- This is an action not related to life and living organisms.
- It is an abiotic factor.
Learn more:
Abiotic factors brainly.com/question/1542938
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