Page 137 - General and Inorganic Chemistry for Advanced Secondary Schools Students Book Form Five and Six

Biology for Secondary Schools

These elements are also referred to as trace elements. They include boron,
copper, iron, chlorine, manganese, zinc, nickel, and molybdenum. Table 6.3
shows functions of microelements in plants, deficiency signs, and effects of their
excess levels.
FOR ONLINE READING ONLY
Table 6.3: Functions, deficiency signs, and effects of excess microelements in
plants
Macroelement Functions Signs of Effects of excess
deficiency
Boron (i) Aids in the (i) Distorted or (i) Scorched
production dead leaves
of sugar and growing tips (ii) Falling off
starch (ii) Hollow of leaves
(ii) Aids in water stems
intake by cells (iii) Deformed
(iii) Important for fruits
seed and fruit (iv) Discoloured
development leaves
(iv) Keeps Calcium
in a soluble
form
Copper (i) Important for (i) Bluish- (i) Iron
normal growth and green leaves deficiency
development (ii) Withering of (ii) Suppressed
(ii) Aids in the leaves growth
formation of (iii) Leaves
proteins
failing to
unfold
(iv) Distorted

growth tips

Chlorine Important for plant (i) Wilting Scorched leaf
metabolism (ii) Stumpy edges
roots

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