Answer:
Bacterial communicable diseases 
Explanation:
Hope it's right
 
        
                    
             
        
        
        
Microtubules originate on the centre of the cell taking the positive end to the periphery of the cell, while the negative end remains turned to the centre of the cell. The melanosomes move along these microtubules using motor proteins desiganted kinesins and dyneins. The kinesins are responsible for moving the melanosomes to the positive end of the microtubule (periphery of the cell) generating dark-colored cells, whereas dyneins move the melanosomes to the negative end of the microtubule (centre of the cell) generating light-colored cells.
 
        
             
        
        
        
Water has special characteristics because liquid water is denser than ice and ice floats on top of liquid water.
Answer: Option A & D
<u>Explanation:</u>
A water molecule is formed by the covalent bonding between two atoms of Hydrogen atom with one atom of Oxygen. In water, the Hydrogen bonds are the one that keeps the water molecule intact.  
When the water molecule freezes the bonding becomes weak as they are separated and set apart which makes the liquid water denser than ice. Normally a substance floats if it is less dense. Ice floats because it is less dense than water.  
 
        
             
        
        
        
Answer: If the temperature increases, then the activity of the lions decreases.