Permanent tissues are derived from

Name the tissue that smoothens bone surface at joints.

The chemical present in the walls of bark of the tree which makes them impervious to gases and water is

Which muscles act involuntarily?
$(i)$ Striated muscles
$(ii)$ Smooth muscles
$(iii)$ Cardiac muscles
$(iv)$ Skeletal muscles

$(a)$ Draw the adipose connective tissue.
$(b)$ Mention one region in the body where this tissue is present and state one function of this tissue.

Flexibility in plants is due to