It is a resin got form the bark of Confiers. It is used as a thinner for oil based paints and organic solvents. Eg: Pinus

It is a gum got from the incisions on the bark of Acacia senegal. It exudes as a viscous liquid, collects in a drop and hardens.

The dye, haematoxylin is obtained from the heart wood of Haematoxylum campechianum used to stain plant materials for observation under microscope, especially the nucleus of the cell.

(a) Cinnamon - Spice got from the bark of the tree. Eg: Cinnamomum.
(b) Rubber - Got from the latex vessels of the inner bark of Hevea brasiliensis.

(i) If the phellogen forms a complete cylinder around the stem, it gives rise to ring barks. Eg: Quercus.
(ii) When the bark is formed in overlapping scale like layers, it is known as scale bark. Eg Guava.
(iii) While ring barks normally do not peel off, scale barks peel off.

(i) Plants secrete resins for their protective benefits. Amber is a fossilized tree resin especially from the wood, which has been appreciated for its colour and natural beauty since Neolithic times.
(ii) Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects.
(iii) Amber is used in jewellery. It has also been used as a healing agent in folk medicine.

60 years old - Age of the Tree.
Reason:
(i) In the cross section of the tree trunk, the lighter (spring wood) and darker (Autumn wood) rings appear in the form of concentric circles.
(ii) One spring wood circle and one autumn wood circle together constitute an annual ring.
(iii) Thus one dark and one light ring would have been formed every year.
(iv) 60 dark and 60 light rings indicate the age of the tree as 60 years.

(i) The log A will last longer for the merchant.
(ii) In any tree the outer part of the wood is pale in colour, is called Sap Wood, while the centre part is darker called Heart Wood.
(iii) Due to the presence of tyloses and their contents, the heartwood becomes coloured, dead and the hardest part of the wood.
(iv) The heartwood is more durable and more resistant to the attack of microorganisms and insects.