The strongest component of the cell wall<span> is a carbohydrate called cellulose, a polymer of glucose. The </span>cell wall gives rigidity<span> and strength to the </span>plant cells<span> which offers protection against mechanical stress. ... The </span>rigidity<span> of primary </span>plant<span> tissues is due to turgor pressure and not from rigid </span>cell walls<span>.</span>
        
                    
             
        
        
        
Answer:
C. Sunlight penetrates to greater depths in land than water
Explanation:
Water is a poor conductor of heat which is why it takes much longer for water to conduct heat than it does land. 
I hope this helped :)
 
        
             
        
        
        
Answer:
The person should be carried in a straight position to prevent damage of spinal cord.
Explanation:
 
        
             
        
        
        
Answer:
True
Explanation:
Sound waves need a medium to travel through. That's why you cant hear sound in space. But you can see light in space and the sun heats up our planet, so yes, light doesnt need a medium to travel through.