(1)       (a)       Sketch the cross-section of a tree.

                        (b)       Label the following parts on the sketch in (a):
                                    (i)         medullary ray;
                                    (ii)        bark;
                                    (iii)       sapwood;
                                    (iv)       annual ring.

                        (c)        State one function of any three of the parts listed in 1(b)

                        (d)       Illustrate with sketches, each of the following timber defects:

Most candidates were able to:

-           sketch the cross-section of a tree;
-           state one function of the parts of a tree;
-           sketch cupping and bowing timber defects in timber.

However, some candidates were unable to label correctly the sapwood and medullary rays in the cross section of the tree.

The expected response is given below:

(a)      

(b)       Label properly  the four given parts                    

(c)        State one function of any three of the parts listed

Bark:

• protects the tree from extreme weather conditions;
• protects the tree from insects and fungi attacks;
• protects the tree from animals;
• protects the tree and its internal structure;
• protects the tree from fire.

Medulary ray:

• to distribute and store food.

Sapwood:

• conveys water and mineral salts to the leaves and branches;
• matures into a heartwood/transforms itself into a heartwood.

Annual Ring

• They are produced by periodic changes in the rate of growth. 

(d)