MCQ 11 Mark
What is the lowest traceable concentration of an element in a plant tissue?
- A
$10^{-12}g/ml$
- B
$10^{-10}g/ml$
- C
$10^{-9}g/ml$
- ✓
$10^{-8}g/ml$
AnswerCorrect option: D. $10^{-8}g/ml$
$10^{-8}g/ml$
View full question & answer→MCQ 21 Mark
Which of the following is a free living aerobic non$-$photosynthetic nitrogen$-$fixer?
View full question & answer→MCQ 31 Mark
The association between blue$-$green algae and fungi occurs in:
View full question & answer→MCQ 41 Mark
Azotobacter and Beijerinckia are the examples of:
AnswerCorrect option: A. Non$-$symbiotic nitrogen$-$fixers.
Non$-$symbiotic nitrogen$-$fixers.
View full question & answer→MCQ 51 Mark
Choose the correct function of magnesium.
AnswerCorrect option: B. It activates the enzymes of respiration and photosynthesis.
Magnesium is absorbed by plants as $Mg^{2+}$
It activates the enzymes of respiration and photosynthesis.
It is involved in the synthesis of $\text{DNA RNA.}$
It is the constituent of ring structure of chlorophyll.
It helps to maintain ribosome structure.
View full question & answer→MCQ 61 Mark
The nitrogen fixing bacterium in the roots of the plants, Alnus is:
MCQ 71 Mark
Which of the following elements is essential for energy related compounds?
- A
- B
- ✓
Magnesium and Phosphorus.
- D
AnswerCorrect option: C. Magnesium and Phosphorus.
Magnesium and Phosphorus.
View full question & answer→MCQ 81 Mark
Bacteria present in root nodules of the leguminous plants are:
MCQ 91 Mark
Number of essential elements in plants is:
AnswerThere are about $17$ mineral elements which are considered as essential for the plants.
They can be grouped into two categories: micronutrients and macronutrients.Macronutrients are present in plants in easily detectable quantities and are $10$ in number.
They include$-$ carbon, oxygen, hydrogen, nitrogen, iron, potassium, calcium, phosphorus, magnesium and sulphur.
They are generally required to build up the plant body, regulate osmotic concentration and take part in biochemical reactions.Micronutrients are present in plants in minute quantities and are $7$ in number.
They include chlorine, manganese, boron, zinc, copper, molybdenum and nickel.
They are generally required in the functioning of enzymes , as cofactors or metal activators.
View full question & answer→MCQ 101 Mark
The most abundant element present in the plant is:
AnswerCarbon is the fourth most abundant element in the universe and is the building block of life on earth.
On earth, carbon circulates through the land, ocean, and atmosphere, creating what is known as the Carbon Cycle.
View full question & answer→MCQ 111 Mark
Boron in green plants assists in:
- ✓
- B
- C
Acting as enzyme cofactor.
- D
View full question & answer→MCQ 121 Mark
Which of the following functions is associated with Nostoc?
AnswerThere is two type of nitrogen-fixing bacteria one is free$-$living and another is symbiotic.
Some bacteria and blue-green algae like Nostoc are free$-$living bacteria and able to fix nitrogen from the atmosphere to enrich the soil with nitrogen and increase the soil fertility.
Rhizobium is the symbiotic bacteria that lives in root nodules of leguminous plants and fixes the atmospheric nitrogen in plants in the usable form.
View full question & answer→MCQ 131 Mark
Element necessary for the middle lamella.
MCQ 141 Mark
Legumes’ roots have swellings called nodules that:
AnswerCorrect option: A. Contain nitrogen$-$fixing bacteria.
View full question & answer→MCQ 151 Mark
Plants can be grown in $($Tick the incorrect option$)$
- A
Soil with essential nutrients.
- B
Water with essential nutrients.
- C
Either water or soil with essential nutrients.
- ✓
Water or soil without essential nutrients.
AnswerCorrect option: D. Water or soil without essential nutrients.
View full question & answer→MCQ 161 Mark
Hydroponics is growing plants in:
- A
- B
- ✓
Solution of mineral nutrients
- D
AnswerCorrect option: C. Solution of mineral nutrients
View full question & answer→MCQ 171 Mark
Chlorosis will occur if a plant is grown in:
AnswerCorrect option: D. $Fe-$free medium.
View full question & answer→MCQ 181 Mark
The element present in middle lamella of cell wall of plants, is:
MCQ 191 Mark
In plants, a common symptom caused by deficiency of $\text{P, K, Ca}$ and $\text{Mg}$ is the:
- A
- B
Formation of anthocyanins.
- C
Poor development of vasculature.
- ✓
Appearance of dead necrotic tissue.
AnswerCorrect option: D. Appearance of dead necrotic tissue.
View full question & answer→MCQ 201 Mark
$\text{NPK}$ denotes.
- A
Nitrogen, Protein, Kinetin.
- B
Nitrogen, Protein, Potassium.
- C
Nitrogen, Potassium, kinetin.
- ✓
Nitrogen, Phosphorus, Potassium.
AnswerCorrect option: D. Nitrogen, Phosphorus, Potassium.
View full question & answer→MCQ 211 Mark
The chief sinks for the mineral elements are $...........?$
View full question & answer→MCQ 221 Mark
Which one of the following is not an essential mineral element for plants while the remaining three are?
MCQ 231 Mark
A plant requires magnesium for.
MCQ 241 Mark
Deficiency symptoms of an element tend to appear first in young leaves. It indicates that the element is relatively immobile. Which one of the following elemental deficiency would$-$ show such symptoms?
View full question & answer→MCQ 251 Mark
Boron in green plants assists in:
MCQ 261 Mark
Non$-$symbiotic nitrogen fixing prokaryote is:
View full question & answer→MCQ 271 Mark
Which of the following is a flowering plant with nodules containing filamentous nitrogen$-$fixing microorganism?
View full question & answer→MCQ 281 Mark
Which of the following is correct set of micronutrient for plants?
- A
$\text{Mo, Zn, Cl, Mg, Ca}$
- ✓
$\text{Cu, Fe, Zn, B, Mn}$
- C
$\text{Mg, Fe, Zn, B, Mn}$
- D
$\text{Mg, Si, Fe, Cu, Ca}$
AnswerCorrect option: B. $\text{Cu, Fe, Zn, B, Mn}$
View full question & answer→MCQ 291 Mark
Blue green algae fix $...........$ directly from air to enhance fertility of soil.
View full question & answer→MCQ 301 Mark
- A
Technique of growing plants in an artificial environment.
- ✓
Technique of growing plants in the absence of soil.
- C
Aeration of nutrient solution.
- D
Both $(b)$ and $(c)$
AnswerCorrect option: B. Technique of growing plants in the absence of soil.
View full question & answer→MCQ 311 Mark
Which of these plants contains nitrogen$-$fixing bacteria?
View full question & answer→MCQ 321 Mark
The plant ash is an indication of:
- ✓
Mineral salts absorbed by plants.
- B
- C
- D
AnswerCorrect option: A. Mineral salts absorbed by plants.
View full question & answer→MCQ 331 Mark
A trace element is an element which:
- A
Is a radioactive and can be traced by geiger counter
- ✓
Is required in very minute amounts
- C
Draws other element out of protoplasm
- D
Was one of the first to be discovered in protoplasm
AnswerCorrect option: B. Is required in very minute amounts
View full question & answer→MCQ 341 Mark
Frame work element in plants are:
- A
Magnesium, copper and iron
- B
Copper, carbon and oxygen
- C
Magnesium, calcium and nitrogen
- ✓
Carbon, hydrogen and oxygen
AnswerCorrect option: D. Carbon, hydrogen and oxygen
View full question & answer→MCQ 351 Mark
Micronutrients are needed in amounts:
- ✓
$8m$ mole$/ \ kg$ dry matter
- B
$18m$ mole$/ \ kg$ dry matter
- C
$25m$ mole$/ \ kg$ dry matter
- D
$30m$ mole$/ \ kg$ dry matter
AnswerCorrect option: A. $8m$ mole$/ \ kg$ dry matter
View full question & answer→MCQ 361 Mark
Which is a free living nitrogen fixing bacterium?
MCQ 371 Mark
AnswerCorrect option: C. Synthesis of chlorophyll.
View full question & answer→MCQ 381 Mark
One of the free$-$living, anaerobic nitrogenfixer is:
View full question & answer→MCQ 391 Mark
Which of the following elements plays an important role in biological nitrogen fixation?
MCQ 401 Mark
View full question & answer→MCQ 411 Mark
Choose the correct match Bladderwort, sundew, venusfly trap.
- A
Nepenthes, Dionea, Drosera.
- B
Nepenthes, Utricularia, Vanda.
- ✓
Utricularia, Drosera, Dionea.
- D
AnswerCorrect option: C. Utricularia, Drosera, Dionea.
View full question & answer→MCQ 421 Mark
Which process brings about ammonification of nitrogen during nitrogen cycle?
- A
- B
- ✓
- D
Nitrogen fixation by rhizobium.
View full question & answer→MCQ 431 Mark
The fixation of free nitrogen by bacteria in the soil protein is only done by:
MCQ 441 Mark
Which element is required for opening and closing of stomata?
MCQ 451 Mark
Match the element with its associated functions/ roles and choose the correct option among given below:
| $A$ |
Boron |
$i.$ |
Splitting of $\text{H2o}$ to liberate $o_2$ during photosynthesis. |
| $B$ |
Mamganese |
$ii.$ |
Needed for synthesis of auxins. |
| $C$ |
Molybdenum |
$iii.$ |
Component of nitrogenase. |
| $D$ |
Zinc |
$iv.$ |
Pollen germinnation. |
| $E$ |
Iron |
$v.$ |
Component of ferredoxin. |
- A
$\text{A(i), B(ii), C(iii), D(iv), E(v)}$
- ✓
$\text{A(iv), B(i), C(iii), D(ii), E(v)}$
- C
$\text{A(iii), B(ii), C(iv), D(v), E(i)}$
- D
$\text{A(ii), B(iii), C(v), D(i), E(iv)}$
AnswerCorrect option: B. $\text{A(iv), B(i), C(iii), D(ii), E(v)}$
View full question & answer→MCQ 461 Mark
Which among the following is a micronutrient?
MCQ 471 Mark
The macronutrients which is essential component of all organic compounds but is not obtained by plants from soil is:
MCQ 481 Mark
'Hunger signs' in plants are:
- A
Sympotms due to poor photosynthesis in plants.
- B
Symptoms due to lesser water absorption in plants.
- ✓
Deficiency symptoms of particular mineral nutrients.
- D
AnswerCorrect option: C. Deficiency symptoms of particular mineral nutrients.
View full question & answer→MCQ 491 Mark
Which element is required in the germination of pollen grain?
MCQ 501 Mark
View full question & answer→MCQ 511 Mark
The charcoal culture experiment is better than water culture experiment because:
- A
- B
Problem of aeration is removed
- C
Charcoal is an inert substance
- ✓
View full question & answer→MCQ 521 Mark
Which of the following elements is almost non$-$essential for plants:
View full question & answer→MCQ 531 Mark
The element needed for synthesis of chlorophyll, is:
MCQ 541 Mark
Carbon is available to crop plants in the form of:
MCQ 551 Mark
Ecosystems obtain nitrogen from outside through the process of:
MCQ 561 Mark
Which of the following is not non$-$essential element for plants?
View full question & answer→MCQ 571 Mark
The two bacteria involved in conversion of ammonia to nitirite, are:
- ✓
Nitrosomonas, Nitrosococcus.
- B
Nitrosomonas, Nitrobacter.
- C
- D
Azotobacter, Nitrosomonas.
AnswerCorrect option: A. Nitrosomonas, Nitrosococcus.
View full question & answer→MCQ 581 Mark
Which of the following are macronutrients?
AnswerCorrect option: C. Both $A$ and $B$
View full question & answer→MCQ 591 Mark
Which aquatic fern performs nitrogen fixation?
MCQ 601 Mark
Manganese toxicity leads to deficiency of:
AnswerManganese toxicity causes deficiency of iron, magnesium and calcium.
View full question & answer→MCQ 611 Mark
With regard to the biological nitrogen fixation by Rhizobium in association with soybean, which one of the following statement$/$ statements does not hold true?
AnswerCorrect option: A. Nitrogenase may require oxygen for its functioning.
View full question & answer→MCQ 621 Mark
- A
- B
- C
- ✓
Growing plants under controlled environment.
AnswerCorrect option: D. Growing plants under controlled environment.
View full question & answer→MCQ 631 Mark
AnswerCorrect option: A. Protecting nitrogenase from $O_2$.
View full question & answer→MCQ 641 Mark
Enzyme involved in nitrogen assimilation:
MCQ 651 Mark
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?
AnswerCorrect option: D. Application of iron and magnesium to promote synthesis of chlorophyll.
View full question & answer→MCQ 661 Mark
Which of the following is not caused by deficiency of mineral nutrition?
- A
- B
- ✓
- D
Shortening of internodes.
View full question & answer→MCQ 671 Mark
Plants absorb carbon dioxide from:
- A
- B
- C
Carbohydrates present in the soil
- ✓
View full question & answer→MCQ 681 Mark
Macronutrients are $..........$ than micronutrients.
- ✓
Needed in greater quantities.
- B
- C
More important for growth.
- D
AnswerCorrect option: A. Needed in greater quantities.
View full question & answer→MCQ 691 Mark
In plant nutrition elements are classified as major or minor depending on
- A
Their availability in the soil.
- B
Their relative production in the ash obtained after burning the plants.
- ✓
Their relative amounts required by the plants.
- D
Their relative importance in plant growth.
AnswerCorrect option: C. Their relative amounts required by the plants.
View full question & answer→MCQ 701 Mark
Which one of the following roles is not characteristic of an essential element?
- A
Being a component of biomolecules.
- ✓
Changing the chemistry of soil.
- C
Being a structural component of energy related chemical compounds.
- D
Activation or inhibition of enzymes.
AnswerCorrect option: B. Changing the chemistry of soil.
Soil is not a living thing and hence essential elements have no role to play in soil chemistry.
View full question & answer→MCQ 711 Mark
Which one of the following is not an essential element for plants?
MCQ 721 Mark
If dead spots are found on leave then it is a symptom of deficiency of which elements?
- A
$\text{K, Mg}$
- ✓
$\text{K, Mo}$
- C
$\text{K, Mn}$
- D
$\text{K, Ca}$
AnswerCorrect option: B. $\text{K, Mo}$
View full question & answer→MCQ 731 Mark
Which one of the following can utilize molecular nitrogen $(N_2)$ as nutrient for growth?
View full question & answer→MCQ 741 Mark
Non$-$essential element in plant is:
View full question & answer→MCQ 751 Mark
Insectivorous plants grow where.
- A
There is carbohydrate deficient soil.
- ✓
There is nitrogen deficient soil.
- C
Vitamin $c$ is required.
- D
AnswerCorrect option: B. There is nitrogen deficient soil.
View full question & answer→MCQ 761 Mark
The process of conversion of ${NO_2}^-$ to $N_2$ is called:
AnswerThe process of conversation of ${NO_2}^-$ to $N_2$ is called denitrification.
View full question & answer→MCQ 771 Mark
Which one of the following symptoms is not due to manganese toxicity in plants?
- A
Calcium translocation in shoot apex is inhibited.
- ✓
Deficiency in both Iron and Nitrogen is induced.
- C
Appearance of brown spot surrounded by chlorotic veins.
- D
AnswerCorrect option: B. Deficiency in both Iron and Nitrogen is induced.
View full question & answer→MCQ 781 Mark
Which one of the following mineral elements plays an in biological nitrogen fixation?
MCQ 791 Mark
The major portion of the dry weight of plants comprises of.
- ✓
Carbon, hydrogen and oxyge.
- B
Nitrogen, phosphorus and potassium.
- C
Calcium, magnesium and sulphur.
- D
Carbon, nitrogen and hydrogen
AnswerCorrect option: A. Carbon, hydrogen and oxyge.
View full question & answer→MCQ 801 Mark
The ability of coralloid roots to fix atmospheric nitrogen is due to the presence of:
AnswerCorrect option: A. Blue$-$green algae
View full question & answer→MCQ 811 Mark
A free living, nitrogen$-$fixing cyanobacterium which can also form symbiotic association with the water fern Azolla is:
View full question & answer→MCQ 821 Mark
- ✓
- B
Manufactured during photosynthesis
- C
- D
Produced by growth horomones
View full question & answer→MCQ 831 Mark
The major role of minor elements inside living organisms is to act as:
- A
Binder of cell structure.
- ✓
$Co-$factors of enzymes.
- C
Building blocks of important amino acids.
- D
AnswerCorrect option: B. $Co-$factors of enzymes.
View full question & answer→MCQ 841 Mark
Which one of the following is not a micronutrient?
MCQ 851 Mark
Oxygen scavanger’s present in root nodules of legumes is:
AnswerLeg$-$haemoglobin is the oxygen scavanger in root nodules of legumes.
View full question & answer→MCQ 861 Mark
Mineral salts which are absorbed by the roots from soil are in the form of:
- A
- B
Very concentrated solution.
- C
- ✓
View full question & answer→MCQ 871 Mark
The plants grown in magnesium deficient but urea sprayed soil would show.
- A
- B
- ✓
- D
Loss of pigments in petals.
View full question & answer→MCQ 881 Mark
- A
Growing of aquatic plants.
- B
Growing of floating aquatic plants.
- C
Growing of plants in sand.
- ✓
Growing of plants in nutrient balanced aqueous medium.
AnswerCorrect option: D. Growing of plants in nutrient balanced aqueous medium.
View full question & answer→MCQ 891 Mark
Which of the following minerals activate the enzymes involved in respiration?
MCQ 901 Mark
Which of the following minerals is required by plants in the greatest quantity?
MCQ 911 Mark
Which one of the following mineral elements plays an important role in biological nitrogen fixation?
MCQ 921 Mark
The core element of chlorophyll is:
MCQ 931 Mark
Which of the following elements is not required for normal growth of the plant?
MCQ 941 Mark
Nodules with nitrogen fixing bacteria are present in:
MCQ 951 Mark
Mineral associated with cytochrome is:
- A
$Cu$
- B
$Mg$
- C
$Fe$ and $Mg$
- ✓
$Fe$ and $Cu$
AnswerCorrect option: D. $Fe$ and $Cu$
View full question & answer→MCQ 961 Mark
The most abundant element found in plants is:
MCQ 971 Mark
The core metal of chlorophyll is:
MCQ 981 Mark
Which one does not fix nitrogen:
AnswerAzotobacter, Anabaena, Nostoc are the nitrogen fixing prokaryotes in lichens, azolla, Cycas while Spirogyra is a green algae which does photosynthesis. It does not fix nitrogen.
View full question & answer→MCQ 991 Mark
Gravel method of hydroponics is called as:
MCQ 1001 Mark
Which among the following is present in the root nodules of leguminous plants?
MCQ 1011 Mark
Grey spots of oat are caused by deficiency of:
MCQ 1021 Mark
What is the minimum amount of an element in terms of mmole per $kg?$
- ✓
$> 10$
- B
$- 10$
- C
$> 20$
- D
$= 20$
AnswerCorrect option: A. $> 10$
View full question & answer→MCQ 1031 Mark
The function of leghaemoglobin during biological nitrogen fixation in the root nodules of legumes, is:
- A
Convert atmospheric nitorgen into ammonia.
- B
Convert ammonia into nitrite.
- ✓
Transport oxygen to all cells.
- D
Protect the enzyme nitrogenase from oxygen.
AnswerCorrect option: C. Transport oxygen to all cells.
View full question & answer→MCQ 1041 Mark
Soil can easily become deficient in $............$ because these ions are negatively charged and do not stick to negatively charged clay particles.
View full question & answer→MCQ 1051 Mark
'Whip$-$tail’ disease in cauliflower is noted due to deficiency of:
View full question & answer→MCQ 1061 Mark
The deficiencies of micronutrients, not only affects 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
$\text{Co, Ni, Mo}$
- B
$\text{Ca, K, Na}$
- C
$\text{Mn, Co, Ca}$
- ✓
$\text{Cu, Mn, Fe}$
AnswerCorrect option: D. $\text{Cu, Mn, Fe}$
View full question & answer→MCQ 1071 Mark
Which of the following micronutrients is important for pollen germination?
MCQ 1081 Mark
Which one of the following mineral elements plays an important role in biological nitrogen fixation?
MCQ 1091 Mark
Which of these organisms does not help in $N_2$ fixation?
AnswerSpirogyra is a filamentous green alga.
They are found in freshwater such as pools, ponds, etc.
They have long thin unbranched filaments of cylindrical cells.
They are not involved in nitrogen fixation.
Whereas Anabaena, Nostoc and Rhizobium play a critical role in nitrogen fixation.
View full question & answer→MCQ 1101 Mark
A free living nitrogen$-$fixing cyanobacterium which can also form symbiotic association with the water fern Azolla is:
View full question & answer→MCQ 1111 Mark
Which of the following is not a macronutrient.
MCQ 1121 Mark
Reaction carried out by $N_2$ fixing microbes include: $\ce{2NH_3 + 3O_2 → 2NO_2 + 2H^+ + 2H_2O} ....(i)$
$\ce{2NO_2$ + $O_2\rightarrow 2NO} ....(ii)$
Which of the following statements about these equations is not true?
- A
Step $(i)$ is carried out by Nitrosomonas or Nitrosococcus.
- B
Step $(ii)$ is carried out by Nitrobacter.
- C
Both steps $(i)$ and $(ii)$ can be called nitrification.
- ✓
Bacteria carrying out these steps are usually photoautotrophs.
AnswerCorrect option: D. Bacteria carrying out these steps are usually photoautotrophs.
Given reactions are of nitrification. The conversion $($oxidation$)$ of ammonia to nitrite is carried out by nitrifying bacteria Nitrosomonas and Nitrosococcus and of nitrite to nitrate by Nitrobacter and Nitrocystis. Bacteria carrying out these steps are chemoautotrophs, which are able to manufacture their organic food from inorganic raw materials with the help of energy derived from exergonic chemical reactions.
View full question & answer→MCQ 1131 Mark
Toxicity of which element leads to the appearance of brown spots on leaves.
AnswerToxicity of manganese leads to the appearance of the brown spots with chlorotic veins.
View full question & answer→MCQ 1141 Mark
The number of essential elements required for normal growth of plant is:
MCQ 1151 Mark
Produce from the hydroponic method have:
MCQ 1161 Mark
Which of the following cannot be an essential element?
- A
Element absolutely necessary for plant's survival.
- ✓
Element which can be replaced with another element.
- C
Element which is directly involved in metabolism.
- D
Element which is directly involved in anabolism.
AnswerCorrect option: B. Element which can be replaced with another element.
View full question & answer→MCQ 1171 Mark
Which one of the following is a micronutrient for plants?
MCQ 1181 Mark
Nitrogen$-$fixation in root nodules of Alnus is brought about by.
View full question & answer→MCQ 1191 Mark
Which of the following is not performed by root hairs?
AnswerCorrect option: B. $CO_2$ uptake.
View full question & answer→MCQ 1201 Mark
An element playing important role in nitrogen fixation is:
MCQ 1211 Mark
The most abundant element present in the plants is:
- ✓
Carbon, hydrogen and oxygen
- B
Nitrogen, phosphorus and potassium
- C
Calcium, magnesium and sulphur
- D
Carbon, nitrogen and hydrogen
AnswerCorrect option: A. Carbon, hydrogen and oxygen
View full question & answer→MCQ 1221 Mark
Which of the following crops would enrich the soil with nitrogen?
MCQ 1231 Mark
Exanthema is due to deficiency of:
MCQ 1241 Mark
- A
Brings about healthy root growth.
- B
- ✓
Retards protein formation.
- D
AnswerCorrect option: C. Retards protein formation.
View full question & answer→MCQ 1251 Mark
What is the role of calcium in plants?
- ✓
- B
Formation of dead tissues.
- C
Formation of xylem fibres.
- D
Formation of phloem fibres.
View full question & answer→MCQ 1261 Mark
Which of the following is not absorbed through soil?
AnswerCarbon is obtained in gaseous form as carbon dioxide, while other mineral elements are obtained from soil.
View full question & answer→MCQ 1271 Mark
The enzyme responsible for atmospheric nitrogen fixation is:
MCQ 1281 Mark
Number of elements needed for healthy growth and development of plants is:
MCQ 1291 Mark
Mineral and vitamins are called$...........?$
View full question & answer→MCQ 1301 Mark
Which one of the following elements is not an essential micronutrient for plant growth?
MCQ 1311 Mark
Which one of the following is not a micronutrient?
MCQ 1321 Mark
The formation of first stable product of nitrogen fixation is catalysed by enzyme.
MCQ 1331 Mark
All the nitrogenase enzyme has been inactivated by radiation. There will be no $...........?$
- A
Fixation of atmospheric nitrogen
- ✓
Fixation of nitrogen by leguminous plants
- C
Conversion of nitrate to nitrite in legumes
- D
Conversion of ammonia to nitrate in soil
AnswerCorrect option: B. Fixation of nitrogen by leguminous plants
View full question & answer→MCQ 1341 Mark
First experiment related to the method of hydroponics was done by:
MCQ 1351 Mark
Which element is located at the centre of the porphyrin ring in chlorophyll?
MCQ 1361 Mark
Blue green algae fix $...........$ directIy from air to enhance fertility of soil?
View full question & answer→MCQ 1371 Mark
A trace element essential for plant growth and radio$-$isotope, which is used in cancer therapy is:
View full question & answer→MCQ 1381 Mark
Certain bacteria living in the soil poor in oxygen, convert nitrates into nitrites and then to free nitrogen and such bacteria are termed as:
MCQ 1391 Mark
Culturing of plants in water$/$ soil$-$less medium is:
View full question & answer→MCQ 1401 Mark
Which of the following is a symbiotic nitrogen fixer?
MCQ 1411 Mark
Which one of the following statements can best explain the term critical concentration of an essential element?
- ✓
Essential element concentration below which plant growth is retarded.
- B
Essential element concentration below which plant growth becomes enhanced.
- C
Essential element concentration below which plant remains in the vegetative phase.
- D
AnswerCorrect option: A. Essential element concentration below which plant growth is retarded.
View full question & answer→MCQ 1421 Mark
Non$-$symbiotic $($free$-$living$)$ aerobic, nitrogen fixing bacterium, is:
View full question & answer→MCQ 1431 Mark
Carbon become available to crop plant in the form of:
AnswerCarbon become available to crop plant in the form of carbon dioxide.
Plants use carbon dioxide during photosynthesis and convert it into the carbohydrate molecule.
This glucose molecule is used as source of energy.
View full question & answer→MCQ 1441 Mark
Manganese is required in.
- ✓
Photolysis of water during photosynthesis.
- B
- C
- D
Plant cell wall formation.
AnswerCorrect option: A. Photolysis of water during photosynthesis.
View full question & answer→MCQ 1451 Mark
Which one of the following elements in plants is not remobilised?
MCQ 1461 Mark
Death of stem and root tips occur due to deficiency of:
MCQ 1471 Mark
Which of the following is a group of micronutrients?
- A
$\text{Ca, Zn, B}$
- ✓
$\text{Fe, Mn, Cu}$
- C
$\text{Cl, C, Ca}$
- D
$\text{Ni, Mo, H}$
AnswerCorrect option: B. $\text{Fe, Mn, Cu}$
Iron, manganese and copper are micronutrients.
View full question & answer→MCQ 1481 Mark
Root nodules are found in:
- A
Some leguminous plants only
- B
- ✓
Some leguminous plants and some other plants also
- D
All leguminous plants but never in other plants
AnswerCorrect option: C. Some leguminous plants and some other plants also
View full question & answer→MCQ 1491 Mark
Premature leaf fall is due to deficiency of:
MCQ 1501 Mark
If, by radiation, all nitrogenase enzyme are inactiveted, then there will be no:
- ✓
Fixation of nitrogen in legumes
- B
Fixation of atmospheric nitrogen
- C
Conversion from nitrate to nitrate in legumes
- D
Conversion from ammonium to nitrate in soil
AnswerCorrect option: A. Fixation of nitrogen in legumes
View full question & answer→MCQ 1511 Mark
Plants die from prolonged water$-$logging because.
- A
Cell sap in the plants becomes too dilute.
- ✓
- C
Nutrients leach down due to excess water.
- D
Soil nutrients become very dilute.
View full question & answer→MCQ 1521 Mark
Zinc as a nutrient is used by the plants in the form of:
- A
$\text{Zn}$
- ✓
$\ce{Zn^{2+}}$
- C
$\text{ZnO}$
- D
$\ce{ZnSO_4}$
AnswerCorrect option: B. $\ce{Zn^{2+}}$
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Technique of growing plants without soil in nutrient solution is called: