Answer:
B Requires building dams that can harm ecosystems
 
        
                    
             
        
        
        
The correct answer is electrons.  
Electron transport chain refers to an array of complexes, which mediates electrons from electron donors to electron acceptors through redox reactions, and combines the transfer of electrons with the transfer of protons through a membrane.  
This produces an electrochemical proton gradient, which instigates the production of ATP. The ultimate electron acceptor in the electron transport chain is oxygen in aerobic respiration and sulfate in anaerobic respiration.  
 
        
             
        
        
        
Answer:
is always a higher organism
Explanation:
lets take an example:
food chain consisting of zooplankton, small fish, big fish and man
as the order goes in the question ,the organism at the end of this food chain is man
 
        
             
        
        
        
Answer:
With respect to the composition of DNA, in an analysis it can be found that the proportions of nucleotides are A + C = G + T (option a).
Explanation:
The proportion of nucleotides in a DNA molecule can be established according to the sequence of these nucleotides on both complementary strands, since the purinic bases of one strand are complemented by the pyrimidinic bases of another:
- <em>Adenine is complemented with Thymine A=T</em>
- <em>Guanine is complemented with Cytosine G=C</em>
From this we can deduce that in a DNA molecule with two chains there will be the same amount of adenine and thymine, as well as the same number of guanine with respect to cytosine, so:
<em>     A + C = G + T</em>
An example of this would be a known DNA molecule (hypothetical), with 5 molecules of Adenine and 7 molecules of Guanine. In this case there are 5 Thymines, complementary with Adenine, and 7 Cytosines like Guanine:
<em>     A + C = G + T</em>
<em>     5 + 7 = 7 + 5</em>
 
        
             
        
        
        
Answer:
Plant cells deal with osmosis by being enclosed in a cell wall.
Animal cells use active transport systems to deal with the problem of osmosis.
Fresh water protists have contractile vacuoles to deal with osmosis.
Many bacteria have cell wall to protect them from osmosis.
Explanation:
Plant cells have a rigid cell wall. If a plant cell is places in a place where the conditions are hypotonic, then the cell will tale up water by osmosis but the cell wall will prevent it from bursting. This condition is termed as the cell being 'turgid'.
As animal cells do not have the rigid cell wall, they use the mechanism of active transport system to stop the cell from bursting during osmosis. In this process, ions are moved out of the cell so that the pressure in the cell due to osmosis can be reduced.
Fresh water protists have a structure present in them called as the contractile vacuole. The contractile vacuole has the capability to remove any excess water from the cell as well storing water if there is not enough water.
Bacteria have peptidoglycan cell walls to prevent osmosis.