geotropism造句怎么写

2、An auxin increases the growth in length of a plant cell, thus causing the curving of a stem, or roof, in phototropism and geotropism.

1、The main stems of a plant show negative geotropism as they grow upwards.

3、The hairy roots transformed by ATCC15834 grew rapidly on MS medium without any phytohormones, and were characterized by strongly branching, clustering and non-geotropism, etc.