Most candidates were able to:
- state the function of the given parts of a tree;
- name the given types of screw;
- label the parts of the screw.
However, they were unable to state the differences between hardwood and softwood trees correctly.
The expected response to question 2 is as given below:
(a) Functions of parts of a tree:
(i) Roots
- hold the tree firmly in the ground.
- absorb mineral salts and water from the ground.
- are used as medicine.
(ii) Trunk
- carries the mineral salts and water from the roots to the leaves.
- transports the prepared food (sap) from the leaves to other parts of the tree.
- stores some of the food.
- supports the crown.
- is the main source of timber.
- serves as source of fuel (e. g. charcoal, firewood, saw dust, e. t. c)
- is the main source of veneer.
(iii) Crown
- manufactures food for the tree.
- gives the tree beauty.
- serves as source of fuel (e. g. charcoal, firewood, e. t. c).
- serves as source of human food, e. g. fruits, seeds, e. t. c.
(iv) Bark
- protects the tree from weather, insect attack and injury.
- is used as medicine.
- is the factory of the tree where wood tissues are
manufactured.
(b) Differences between hardwoods and softwoods
Hardwoods Softwoods
- Have broad leaves
- Shed their leaves
annually/are deciduous
- Have their seeds encased
- Are pored
- Are angiosperms
- Are dicotyledons
|
- Have needle-like leaves
- Have evergreen leaves
- Have naked seeds
- Are non-pored
- Are gymnosperms
- Are conifers
|
(c) (i) X - countersunk head screw
Y - round head screw
Z - raised head screw
(ii) P - gauge
Q - thread
R - slot
