What is the main function of $WBC$?

Match the column $(A)$ with the column $(B)$:

Column $(A)$	Column $(B)$
$(a)$ Parenchyma	$(i)$ Thin walled,packing cells
$(b)$ Photosynthesis	$(ii)$ Carbon fixation
$(c)$ Aerenchyma	$(iii)$ Localized thickenings
$(d)$ Collenchyma	$(iv)$ Buoyancy
$(e)$ Permanent tissue	$(v)$ Sclerenchyma

Why is the epidermis important for plants?

Give short answers:
$(i)$ What is the function of cambium?
$(ii)$ What is meant by lignin? Where is it present?
$(iii)$ What are the characteristics of cells of epidermis?

The dead element present in the phloem is

The intestine absorbs digested food materials. Which type of epithelial cells are responsible for this?