The Effects of Temperature on the Durations of the Different Stages of Cell Division in the Root-tip

Abstract

A new technique for determining the durations of the different phases of division is described. It is shown that at 15° C. the mean durations of the several phases in the root-tip of the pea are as follows: interphase 23 hours; prophase 2 hours; metaphase 25 minutes; anaphase 5 minutes; telophase 22 minutes. The effects of different temperatures have been determined, and it is shown that all stages are accelerated by an increase in temperature from 15° to 25° C, the ratios of the durations at the two temperatures being about 2-o or slightly less. It is suggested that since interphase is the longest stage of the division cycle, in terms of growth effects on this stage are the most significant.