There are several information's of immense importance already given in the question. Based on those information's the answer can be easily deduced. 
Initial number of bacteria in the culture = 1000
Number of bacteria after t hours = 1000 (2)^t
Then
1000 (2)^t = 50000
2 ^t = 50
t = 5.6
I hope the procedure is clear enough for you to understand.
        
             
        
        
        
Answer:
9- C
cellulose strengthens the cell walls present in a plant 
enzymes and antibodies are made of proteins 
water is the universal solvent.
10- C, all 3
1- cytoplasm contains about 85% of water, which helps in movement within the cells.
2- urine contains 95% of water, and it dissolve urea and salts in it.
3- plasma contains 90% of water, so we can say that water allows transportation of substances in the blood.
 
        
             
        
        
        
Answer:
The nucleus is an organelle found in eukaryotic cells. 
Explanation:
 
        
             
        
        
        
It's hard to explain but it would like, be less wild than the seasons we have today.
        
             
        
        
        
The kinetic energy of an object depends on both its mass and its speed. Kinetic energy increased as mass and speed are increased.