Cual es el proceso de sucesion

Which of the following is not a way in which a vascular plant's xylem and phloem are similar?

Apopulation of black bears depends on salmon from a stream for food. if a drought causes the stream to run dry one year, how will this likely impact the black bear population?

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.