Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Plants require inorganic mineral ions for healthy growth, which are absorbed from the soil through root hair cells via active transport.
Nitrate ions () are essential for the synthesis of amino acids. These amino acids are then polymerized to form proteins, which are necessary for cell growth and repair.
Magnesium ions () are the central constituent of the chlorophyll molecule. Chlorophyll is the pigment responsible for absorbing light energy for photosynthesis.
A deficiency in Nitrate ions () results in stunted growth and the yellowing of older leaves, as the plant cannot produce enough protein for new tissues.
A deficiency in Magnesium ions () leads to chlorosis, a condition where leaves turn yellow (specifically between the veins) because the plant cannot synthesize chlorophyll.
Mineral uptake often occurs against a concentration gradient, requiring energy in the form of generated during aerobic respiration in the root cells.
📐Formulae
💡Examples
Problem 1:
A student grows a pea plant in a solution lacking Magnesium () ions. Predict the visual effect on the leaves and the impact on the plant's biomass.
Solution:
The leaves will develop interveinal chlorosis (yellowing), and the total biomass will decrease.
Explanation:
Without , the plant cannot produce chlorophyll. This reduces the rate of photosynthesis, meaning less glucose () is produced. Consequently, there is less energy and raw material for growth, leading to a reduction in biomass.
Problem 2:
Explain why a plant suffering from a deficiency of Nitrate () ions exhibits stunted growth.
Solution:
The plant lacks the necessary nitrogen to build proteins.
Explanation:
Nitrate ions () provide the nitrogen required to make amino acids. Amino acids are the building blocks of proteins, which include enzymes and structural components. Without sufficient protein synthesis, the rate of cell division and expansion is limited, resulting in stunted growth.