Explain the significance of phytoplankton to the aquatic food webs.

Asolution of an enzyme and a substrate was placed in a water bath and the temperature of the reaction was raised gradually. the graph shown was plotted at the end of the experiment. what can be concluded from the graph? a) temperature has no effect on the activity of the enzyme. b) the effect of temperature on the enzyme is unpredictable. c) the enzyme shows increased activity up to a certain temperature. d) the activity of the enzyme is inversely proportional to the temperature.

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.

Adistinctive characteristic of mammals that is not observed in other vertebrates is