Consider the following statements: It is a critical structural com...
Mineral nutrients are essential for the growth of the plants. The absence of any mineral nutrient leads to abnormalities in the growth of the plant.
The functions of some of the important macro (required in large amounts) and micro (required in small amounts) mineral nutrients are as follows: - Magnesium is a critical structural component of the chlorophyll molecule and is necessary for functioning of plant enzymes to produce carbohydrates, sugars and fats. It is used for fruit and nut formation and essential for germination of seeds. Deficient plants appear chlorotic, show yellowing between veins of older leaves; leaves may droop. Magnesium is leached by watering and must be supplied when feeding. It can be applied as a foliar spray to correct deficiencies. Hence the correct option is (a).
- Sulphur is a structural component of amino acids, proteins, vitamins and enzymes and is essential to produce chlorophyll. It imparts flavor to many vegetables. Deficiencies show as light green leaves. Sulphur is readily lost by leaching from soils and should be applied with a nutrient formula. Some water supplies may contain Sulphur.
- Calcium activates enzymes, is a structural component of cell walls, influences water movement in cells and is necessary for cell growth and division. Some plants must have calcium to take up nitrogen and other minerals. Calcium is easily leached. Calcium, once deposited in plant tissue, is immobile (non-translocatable) so there must be a constant supply for growth. Deficiency causes stunting of new growth in stems, flowers and roots. Symptoms range from distorted new growth to black spots on leaves and fruit.
- Yellow leaf margins may also appear.
- Iron is necessary for many enzyme functions and as a catalyst for the synthesis of chlorophyll. It is essential for the young growing parts of plants. Deficiencies are pale leaf color of young leaves followed by yellowing of leaves and large veins. Iron is lost by leaching and is held in the lower portions of the soil structure. Under conditions of high pH (alkaline) iron is rendered unavailable to plants. When soils are alkaline, iron may be abundant but unavailable. Applications of an acid nutrient formula containing iron chelates, held in soluble form, should correct the problem.
- The various life processes of living organisms require at least 40 elements in different quantities. Elements that are needed in large amount are called macronutrients. For example, carbon, hydrogen, oxygen (components of all organic compounds), nitrogen, potassium, calcium, sodium, magnesium, iron, phosphorous and sulphur. They all perform various functions.
- Substances required in small amounts are called micronutrients. They include copper, manganese, selenium, zinc, molybdenum, boron, silicon, etc. Some of the micronutrients (e.g. Zinc, Boron) may often serve as limiting factors to affect the growth, survival, and propagation of living organisms.
Consider the following statements: It is a critical structural com...
Magnesium is the essential plant macro-nutrient referred to in the given statements.
Explanation:
Magnesium plays a crucial role in various physiological and biochemical processes in plants. It is an essential component of the chlorophyll molecule, which is responsible for capturing sunlight and converting it into chemical energy through photosynthesis. Thus, magnesium is critical for photosynthesis, the process by which plants produce glucose and oxygen.
Additionally, magnesium is involved in the activation of numerous enzymes and is required for the synthesis of nucleic acids and proteins. It is also necessary for the metabolism of carbohydrates, lipids, and minerals in plants.
The second statement mentions that magnesium is used for fruit and nut formation and is essential for seed germination. This is because magnesium is involved in the synthesis and transport of carbohydrates and sugars, which are crucial for the development and maturation of fruits and seeds. It also promotes proper cell division and differentiation during seed germination.
Deficiency of magnesium can lead to various symptoms in plants. The third statement points out that magnesium deficiency causes yellowing between the veins of older leaves, a condition known as interveinal chlorosis. This is because chlorophyll production is impaired, resulting in the loss of green pigmentation. As a result, plants may also experience leaf drop or premature leaf senescence.
In conclusion, the given statements refer to magnesium as the essential plant macro-nutrient. Magnesium is critical for chlorophyll synthesis, photosynthesis, enzyme activation, carbohydrate metabolism, and fruit and seed development. Its deficiency leads to interveinal chlorosis and leaf drop.
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