Question

The secondary wood of Pinus is characterised by

• A. Presence of resin cells
• B. Presence of resin ducts
• C. Absence of resin ducts
• D. Presence of vessels

Answer 1

The correct option is B Presence of resin ducts

The presence of resin ducts is a charcateristic feature of all the conifers. The ducts may be normal vertical, normal horizontal or vertical traumatic. Normal ducts are elongated and usually occur singly and found in the Pinaceae. The resin ducts are lined with epithelial lining, whose cell walls may be thick or thin and secrete resin. In a resin duct, the number of epithelial cells is six or less than six per duct.

Sharp demarcation between growth rings, as well as the numerous resin canals is visible in transverse section of Pinus.