Question

Describe the stages in embryo development in a dicot plant.

Answer 1

Stages in dicot embryo development: 

• The zygote undergoes transverse division forming a large basal cell and a small apical or terminal cell. 
• The large basal cell enlarges and undergoes transverse division to from a group of 6–10 cells called suspensor. 
• The first cell of the suspensor towards the micropylar end is called haustorium, whereas the last cell of the suspensor toward the chalazal end is called hypophysis that later develops into radicle. 
• The smaller terminal or apical cell undergoes one vertical division. The two cells formed from terminal cell divide by a transverse division thus forming four embryonal cell (quadrant stage).  
• Finally these four cells divide vertically forming 8-celled proembryo (octate stage). Four cells at the apex give rise to plumule and another four give rise to hypocotyl except its tip.