Growth rings are formed due to activity of
Extrastelar cambium
Intrastelar cambium
Interstelar cambium
Both $(a)$ and $(c)$
Which tissue gives rise to secondary growth?
Trunks of some of the aged tree species appear to be composed of several fused trunks. Is it a physiological or anatomical abnormality ? Explain in detail.
One year's growth in length of a young woody shoot is the distance between successive