Answer:
 An acid increases the concentration of H+ ions. A base is a substance that releases hydroxide (OH-) ions in aqueous solution, donates electrons and accepts protons.
Acid:Lemons, oranges, vinegar
Base:Soap, toothpaste, bleach, cleaning agents, limewater,
Explanation:
 
        
             
        
        
        
The correct answer is a - Lipid
Lipids are not considered as macromolecules because unlike proteins, carbohydrates and nucleic acids which polymers, lipids are composed of a single unit made up a glycerol backbone to which two or three fatty acids are linked.
Lipids are not polymers made up of individual subunits called monomers. They contain only  one molecule and are not macromolecuels.
Examples of lipids include waxes, steroids, phospholipids and detergents. Lipids are generally hydrophobic and insoluble in water.
 
        
             
        
        
        
The answer is A.
The cuticle is a protective film that is non cellular covering the outer cell layer (epidermis) of green, aerial parts of plants. Cuticles protect plants against drying (desiccation), UV radiation, and various kinds of physical, chemical and (micro)biological agents.
The cuticle also provides some support. Actually the cuticle which protects the underlying tissues has basically the same function as our own skin.
In several groups of plants, cuticles are very resistant. Only few groups do not generally have highly resistant cuticles e.g. ferns and lycopods.
        
                    
             
        
        
        
Answer:
B . The hinge joint of the elbow.
Explanation:
Uniaxial joint allows for motion in a single phase.