Energy in ecosystems must be continuously supplied by the sun  as the warmth from the sun allows plants to grow plus photosynthesis depends on the sun's energy also. Animals also depend on the sun for warmth to survive (or else hibernate). Also, the sun powers the water cycle, the carbon cycle and the nitrogen cycle
 
        
             
        
        
        
Between a cation, which is usually a metal, and an anion, which is usually a nonmetal. A covalent bond involves a pair of electrons being shared between atoms.
        
             
        
        
        
Marine biologists study changes in the ocean. so they will look at the chemical composition of deep waters and see how consecrated the oxygen is. They will also study the movements of the plates because when planted move it usually makes new food for deep life
they will also check animal concentrations in certain areas. 
Another thing they do is track animal movements. this could be by putting a tracker on a whale or a shark or anything and watching its depths it goes or watching the distance it goes in a day.
        
                    
             
        
        
        
Answer:
D
an increase in the length of the fatty acid tails.
Explanation:
As average annual temperatures decrease, we would expect to find phospholipids within the cell membranes of organisms to have both saturated
and unsaturated fatty acid tails. Saturated fatty acids tails are arranged linearly, in a way that maximizes interactions between the tails and
decreases bilayer fluidity. Unsaturated fatty acids, on the other hand, have more distance between the tails, fewer intermolecular interactions and
more membrane fluidity. Longer tails and decreased cholesterol also decrease fluidity
 
        
                    
             
        
        
        
The two strands of a DNA molecule have complementary base pairs, the nucleotide sequence of each strand automatically supplies the information needed to produce its partner.