Answer:
E-You disagree because the resulting increase in phytoplankton at the surface would inhibit sunlight from penetrating into the water, thus inhibiting photosynthesis in the submerged plants.
Explanation:
Eutrophication is the process wherein nutrients specifically phosphorus and nitrogen are present in excess in a water body such as a lake. The increased concentration of nutrients promoter the growth of cyanobacteria and algae such as phytoplankton. 
The increased population of phytoplankton in surface water reduces the oxygen availability and clarity of water for the organisms present in deeper layers.  Also, reduced clarity of water limits the amount of solar radiations penetrating the surface water to reach the deeper layers. 
Increased nutrient levels of the lake would rather inhibit the growth of submerged plants due to reduced availability of sunlight as caused by presence of phytoplankton in surface water.  
 
        
             
        
        
        
They typically sleep about 16-17 hours a day; that’s a lot!
        
             
        
        
        
The correct answer is a theory.  
A theory is a rational and contemplative kind of generalizing or abstract thinking or the outcomes of such thinking. On the basis of the context, the outcomes might involve generalized illustrations of how nature functions.  
A theory can be a source of knowledge that may or may not is related to the specific explanatory models. To theorize is to create the body of knowledge.  
 
        
             
        
        
        
Answer:
Testcrosses clarify linkage because each phenotypic class of progeny corresponds to each gamete type produced by the dihybrid parent.
Explanation:
- A test cross involves the crossing of an individual with another phenotypically recessive individual so as to determine the zygosity of the former by analyses of the proportions of offspring phenotypes.
- In order to determine linkage, the test cross shows that if the parentals are more than the recombinants, we can say that the two genes such as b and c  are genetically linked and therefore, they must be on the same chromosome.
- Also, the test-crosses help to find out which alleles came from which parent.
- By setting up testcrosses in which one parent is homozygous for the recessive alleles of both genes,we can analyze the gene combinations received in the gametes from the other, doubly heterozygous parent.