AP and TS EAMCET Medical 2020 Model Paper 1

CORRECT statements from the following
I) Vascular cambium is generally more active on the innerside than the outer
II) During secondary growth in dicot stems, primary xylem remains more orless intact in or around the centre
III) Phellogen is made of narrow, thin-walled and nearly rectangular cells
IV) Lenticels are ventilating structures of woody dicot stems