Answer:
Comparative anatomy.
Explanation:
Comparative anatomy is a branch of science in which we study about similarities and differences present in different organisms. This type of study is very important for the classification of living organisms. Comparative anatomy tells us about the evolution of an organism. Scientists study DNA, embronic structure and the internal structure of species to see the evolution of different organisms.
Salt concentration is the factor among the following factors given in the question that does not vary between a fast flowing river and a pond that receives no water input. The correct option among all the options that are given in the question is the second option. I hope the answer comes to your help.
Solution:
Comparison characteristics is known as the Paint chips, random glass fragments, and synthetic fibers all exhibit.
Thus this the required answer.