Generally, the graph line will begin as a straight line when the substrate concentration is low. At very low substrate concentrations, the rate is proportional to the substrate concentration. As substrate concentration increases, it affects the enzymatic reaction, so the rate will change and the line will change.
Eukaryotic cells do not have a nucleus. The nucleus is where DNA, your genetic material, is usually stored. Prokaryotic cells do not have a nucleus. The DNA just floats around the cell instead of staying in one designated area.
Cartilaginous fish do not contain any bones - their skeleton is made up of cartilage.
A dichotomous key involves 3 keys