Answer: B
Explanation: Osmosis is the movement of water through a semipermeable membrane according to the concentration gradient of water across the membrane, which is inversely proportional to the concentration of solutes.
 
        
                    
             
        
        
        
Answer:
1. physical and chemical barriers
2.non-specific innate response
3. specific adaptive responses
Explanation:
 
        
             
        
        
        
White blood cells use "legs" to grab ahold of the blood vessel walls to inch their way forward.
        
                    
             
        
        
        
Answer: d. Predators avoid prey that are in their prime in order to maintain a high reproductive rate in the prey population, and hence 'grow' prey for the future.
Explanation:
A predator can be define as an organism superior and strong enough to kill inferior and weaker organism. This organism kill other organism to obtain it as food. A prey is an organism which is weak and cannot defend itself from the attack of the superior organism. 
d. is the correct option. This is because the predators do not bother about the age and strength of the prey. They attack over them whether the prey is weak , young, prime, or old and try to obtain it as food.