Q1. It is observed that deficiency of a particular element showed its symptoms initially in older leaves and than younger leaves.
• Does it indicate that the element is actively mobilized or relatively immobile?
• Name two elements which are highly mobile and two which are relatively immobile.
• How is the aspect of mobility of elements important to horticulture and agriculture?
Ans.1 A) This is actively mobilized.
B) Highly mobile elements: Nitrogen and magnesium. Relatively immobile: Calcium and Boron.
C) The symptoms of deficiency of mobile elements are more pronounced in the older leaves and symptoms of deficiency of relatively immobile elements appear first in younger leaves. So this information can be utilized in horticulture as well as agriculture to get a broad idea of deficiency
elements in plants.
Q2. How are plants grown in glass containers to judge essential elements?
Ans.2 In the solution culture the plants are grown in pure nutrient media with only required elements. The glass containers are covered with black paper to protect roots from direct light. In other glass containers plant is allowed to grow artificially with same nutritive culture that contains all essential elements except one and its essentiality is to be judged. They are compared with the control plant grown in balanced nutrient medium. When there is any change in morphological features compared with normal plant this may be due to deficiency of specific element.
Q3. A farmer adds azotobacter culture to the soil before sowing maize. How does it increase the yield of maize?
Ans.3 Azotobacter provides nitrogen fixing bacteria which converts free nitrogen into nitrate and nitrites it increases soil fertility.
Ques. Sulphur is an important nutrient for optimum growth and productivity in
(a) oilseed crops (b) pulse crops
(c) cereals (d) fibre crops.
Ques. Farmers in a particular region were concerned that pre-mature yellowing of leaves of a pulse crop might cause decrease in the yield. Which treatment could be most beneficial to obtain maximum seed yield?
(a) Application of iron and magnesium to promote synthesis of chlorophyll
(b) Frequent irrigation of the crop
(c) Treatment of the plants with cytokinins along with a small dose of nitrogenous fertilizer
(d) Removal of all yellow leaves and spraying the remaining green leaves with 2, 4, 5-trichlorophenoxy acetic acid
Ques. The deficiencies of micronutrients, not only affect growth of plants but also vital functions such as photosynthetic and mitochondrial electron flow. Among the list given below, which group of three elements shall affect most, both photosynthetic and mitochondrial electron transport?
(a) Co, Ni, Mo (b) Ca, K, Na
(c) Mn, Co, Ca (d) Cu, Mn, Fe
Ques. Gray spots of oat are caused by deficiency of
(a) Cu (b) Zn
(c) Mn (d) Fe.
Ques. Boron in green plants assists in
(a) activation of enzymes
(b) acting as enzyme co-factor
(d) sugar transport.
Ques. Mg is a component of
(a) chlorophyll (b) cytochrome
(c) haemoglobin (d) haemocyanin.
Ques. Plants take zinc in the form of
(a) ZnSO4 (b) Zn++
(c) ZnO (d) Zn.
Ques. When the plants are grown in magnesium deficient but urea rich soil, the symptoms expressed are
(a) yellowish leaves (b) colourless petiole
(c) dark green leaves (d) shoot apex die.
Ques. Which of the following is not caused by deficiency of mineral nutrition?
(b) Shortening of internode
Ques. Which one of the following elements is almost nonessential for plants?
(a) Zn (b) Na
(c) Ca (d) Mo
Ques. Which of the following elements plays an important role in biological nitrogen fixation?
(a) Copper (b) Molybdenum
(c) Zinc (d) Manganese
Ques. Mineral associated with cytochrome is
(a) Cu (b) Mg
(c) Cu and Mg (d) Fe.
Ques. Which one is an essential mineral, not constituent of any enzyme but stimulates the activity of many enzymes?
(a) Zn (b) Mn
(c) K (d) Mg
Ques. Phosphorus and nitrogen ions generally get depleted in soil because they usually occur as
(a) neutral ions
(b) negatively charged ions
(c) positively charged ions
(d) both positively and negatively charged but disproportionate mixture.
Ques. Passive absorption of minerals depends on
(b) temperature and metabolic inhibitor
(c) metabolic inhibitor
Ques. The product(s) of reaction catalysed by nitrogenase in root nodules of leguminous plants is/are
(a) ammonia alone
(b) nitrate alone
(c) ammonia and oxygen
(d) ammonia and hydrogen.
Ques. Thiobacillus is a group of bacteria helpful in carrying out
(b) nitrogen fixation
(c) chemoautotrophic fixation
Ques. Which of the following bacteria reduce nitrate in soil into nitrogen?
(a) Nitrobacter (b) Nitrococcus
(c) Thiobacillus (d) Nitrosomonas
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