The kidneys remove from the blood the nitrogenous wastes such as urea, as well as salts and excess water, and excrete them in the form of urine.  hope this helps
 
        
             
        
        
        
Answer:domain bacteria, kingdom, eubacteria 
Explanation:
 
        
             
        
        
        
Answer:
1. Ser and Gln are polar amino acids. 
2. The Leu side chain does not form hydrogen bonds with other amino acids.
3. Phe can undergo oxidation to form Tyr. 
4. Lysine has one stereocenter (chiral center).
Explanation:
Serine and glutamine are the polar amino acids with uncharged side group. Serine has a "CH2OH" group as its side chain and the presence of hydroxyl group makes it a polar amino acid. Glutamine is one of the amides derived from other amino acids present in proteins.  
Leucine is a nonpolar amino acid with an aliphatic side chain and tends to cluster within the proteins to stay away from the surrounding watery medium. Its aliphatic R group does not form any hydrogen bonds to other amino acids.  
Phenylalanine is a nonpolar amino acid with an aromatic R group. Oxidation of aromatic R group of phenylalanine converts it into tyrosine which has an additional hydroxyl group in its side chain.
The chiral center is the carbon to which four different functional groups are bonded. The central alpha carbon atom of lysine is bonded to an amino group, carboxyl group, a hydrogen atom, and one positively charged R group which in turn makes it a chiral center.  
 
        
             
        
        
        
1. Simple optical microscope. One lens. 
Disadvantage: Only Van Leeuwenhoek made them, and he's dead. 
Advantage: Worked pretty well. With them, Van Leeuwenhoek discovered protozoa and bacteria.
2. Compound optical microscope. Has both an ocular and objective lens. 
Disadvantage: limited resolution. Can resolve bacteria, but not smaller things like viruses. 
Advantage: can be used with live specimens (using phase contrast or polarized or other special illumination). 
3. Binocular dissecting microscope (optic). Has a pair of ocular and objective lenses, and supposedly presents a "3D" view of the specimen to the viewer (I was never able to see in 3D using these darn things). 
Disadvantage: Limited magnification 
Advantage: Can be used to perform surgery on small but not microscopic specimens, such as fruit flies. Is used in "microsurgery" in hospitals too. 
Hope this helps buddy!
        
                    
             
        
        
        
Answer: True 
Explanation:
Biology itself is the study of living things and their vital processes that deals with all the physicochemical aspects of life.
Biologists attempt in all way to describe something completely in detailed. They try to explain reasons and how organism behave how the behave.
Using descriptive science biologists involve descriptive research; that is, observing, recording, describing, and classifying biological phenomena.