Vascular bundle with cambium is called

What are the living cells present in the lenticel called?

$A$ vascular bundle in which the phloem surrounds the xylem is called .....

$A$ student observed grass and $Hibiscus$ plants in his garden during noon. To his surprise,only the leaves of grass were found rolled inwards. The reason could be

Pith is a central part of the ground tissue composed of which of the following cells?

Nucleus is absent in