State whether the following statement is true or false:
The cells of collenchyma are living,elongated,and irregularly thickened at the corners.

Justify by giving two points that cartilage is a tissue. What is its matrix made of? Where are these tissues found in our body?

State any three points of difference between your limb and heart muscles.

$(a)$ Give reasons for the following:
$(i)$ Multicellular organisms are considered more efficient.
$(ii)$ Sclerenchyma cells have a narrow lumen.
$(iii)$ Epidermis is thicker in desert plants though it is usually single layered.
$(b)$ Name the following:
$(i)$ Tissue that occurs in specific regions of growth.
$(ii)$ Tissue present at the growing tips of stems and roots.
$(iii)$ Tissue at the base of the leaves or internodes on twigs.
$(iv)$ Basic packing tissue in the form of a few layers of cells.

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

State the chemical composition of the solid matrix of cartilage.