Which of the following is falseabout dynamic instability of a microtubule end? a) during a growth phase, assembly of gtp-tubulin is faster than incorporated gtp is hydrolyzed, forming a gtp-cap. b) during a catastrophe phase, hydrolysis of incorporated gtp is faster than gtp-tubulin addition, forming a gdp-cap. c) during rescue, gtp-tubulin assembles fast enough to reestablish a gtp cap. d) each end of a microtubule can undergo dynamic instability independently. e) all answers are true.