, Question 1 [25]
1.1. Briefly EXPLAIN the following terms:
1.1.1 Anoxia
1.1.2 Macronutrients
1.1.3 Deficient concentration
1.1.4 Phytosiderophores
1.1.5 Chelating agent (5 x 2)
1.2. Distinguish between bulk flow and diffusion.
(5)
1.3. Write explanatory notes on how plants
regulate the uptake of toxic elements
such as heavy metals. (5)
1.4. Explain the source-sink principle in plants.
(5)
Question 2 [30]
2.1. Summarise how carbon allocation between
sucrose and starch synthesis is balanced to
maintain an efficient operation of photosynthesis.
(10)
2.2. List Five examples of mineral elements that are
involved in enzyme action and
, explain how these elements affect enzyme
action. (10)
2.3. Explain how commercial chelating agents work
(mechanism) with regard to iron
deficiencies in limy soils. (10)
Question 3 [15]
3.1. Discuss the phenomenon of cation
exchange in soils, as well as the agricultural
problem of the leaching of anions such as
nitrate. (10)
3.2. Explain the difference between active and
passive transport of solutes. (5)
Total marks: 70
, Question 1 [25 Marks]
1.1 Explanation of Terms (5 x 2 = 10 marks)
1.1.1 Anoxia
Anoxia refers to a condition in which there is a
complete absence of oxygen in plant tissues
or the surrounding environment. This often
occurs in waterlogged soils, where oxygen
diffusion is restricted, leading to stress in root
systems.
1.1.2 Macronutrients
Macronutrients are essential elements
required by plants in large quantities for
growth and development. Examples include
nitrogen (N), phosphorus (P), and
potassium (K). These nutrients are involved
in structural, metabolic, and physiological
functions.
1.1.3 Deficient Concentration
This is the concentration level of a nutrient
below which a plant shows deficiency
symptoms and cannot complete its life cycle.
At this level, growth and yield are negatively
affected due to insufficient nutrient availability.
1.1. Briefly EXPLAIN the following terms:
1.1.1 Anoxia
1.1.2 Macronutrients
1.1.3 Deficient concentration
1.1.4 Phytosiderophores
1.1.5 Chelating agent (5 x 2)
1.2. Distinguish between bulk flow and diffusion.
(5)
1.3. Write explanatory notes on how plants
regulate the uptake of toxic elements
such as heavy metals. (5)
1.4. Explain the source-sink principle in plants.
(5)
Question 2 [30]
2.1. Summarise how carbon allocation between
sucrose and starch synthesis is balanced to
maintain an efficient operation of photosynthesis.
(10)
2.2. List Five examples of mineral elements that are
involved in enzyme action and
, explain how these elements affect enzyme
action. (10)
2.3. Explain how commercial chelating agents work
(mechanism) with regard to iron
deficiencies in limy soils. (10)
Question 3 [15]
3.1. Discuss the phenomenon of cation
exchange in soils, as well as the agricultural
problem of the leaching of anions such as
nitrate. (10)
3.2. Explain the difference between active and
passive transport of solutes. (5)
Total marks: 70
, Question 1 [25 Marks]
1.1 Explanation of Terms (5 x 2 = 10 marks)
1.1.1 Anoxia
Anoxia refers to a condition in which there is a
complete absence of oxygen in plant tissues
or the surrounding environment. This often
occurs in waterlogged soils, where oxygen
diffusion is restricted, leading to stress in root
systems.
1.1.2 Macronutrients
Macronutrients are essential elements
required by plants in large quantities for
growth and development. Examples include
nitrogen (N), phosphorus (P), and
potassium (K). These nutrients are involved
in structural, metabolic, and physiological
functions.
1.1.3 Deficient Concentration
This is the concentration level of a nutrient
below which a plant shows deficiency
symptoms and cannot complete its life cycle.
At this level, growth and yield are negatively
affected due to insufficient nutrient availability.
