Proplastid a self - duplicating undifferentiated plastid , about 0 . 5 - 1 m in diameter and found in the meristematic regions of plants . they grow and develop into plastids of different types 前質(zhì)體:能夠自我復(fù)制的沒有分化的質(zhì)體,直徑約0 . 5 - 1微米,發(fā)現(xiàn)于植物分生組織區(qū)域。它們生長(zhǎng)發(fā)育為不同類型的質(zhì)體。