Critical Concentration

Q. (a) Moderate decrease or increase of micronutrients causes deficiency and toxicity symptoms respectively.
(b) Excess of manganese causes toxicity of iron, calcium and molybdenum.
(c) A macronutrient is said to be toxic when present below a critical concentration.

1. Only (b) is correct
2. (b) and (c) are correct
3. Only (a) is correct
4. (a) and (c) are correct

Q.

Which one of the following statements can best explain the term critical concentration of an essential element?

1. Essential element concentration below which plant growth is retarded

2. Essential element concentration below which plant growth becomes stunted

3. Essential element concentration below which plant remains in the vegetative phase

4. None of the above

Q.

Explain with examples: macronutrients, micronutrients, beneficial nutrients, toxic elements and essential elements.

Q. Assertion: Plant exhibits deficiency symptoms
Reason: It receives nutrients below critical concentration

1. Both assertion & reason are correct but the reason is not the correct explanation of assertion.
2. Assertion is correct but the reason is incorrect
3. Both assertion & reason are incorrect
4. Both assertion & reason are correct and the reason is the correct explanation of assertion.

Q.

Assertion: Deficiency symptoms occur if the soil is lacking any particular element.​

Reason: Excess minerals cause toxicity.​

1. If both assertion and reason are true then the reason is not the correct explanation of assertion
2. If an assertion is true but the reason is false
3. If both assertion and reason are false
4. If both assertion and reason are true and the reason is the correct explanation of assertion.

Q. Which of the following statements is incorrect?

1. Beneficial elements include sodium, silicon, cobalt and selenium
2. Manganese toxicity induces deficiencies of iron and calcium
3. If there is a deficiency of mobile nutrients, the symptoms are first seen in newer parts of the plant
4. Below critical concentration, nutrient levels limit plant growth
   

Q. Which of the following statements is correct statements?
a) Moderate decrease or increase of micronutrients causes deficiency and toxicity symptoms respectively.
(b) Excess of manganese causes toxicity of iron, calcium and molybdenum.
(c) A macronutrient is said to be toxic when present below a critical concentration.

1. Only (a) is correct
2. Only (b) is correct
3. (a) and (c) are correct
4. (b) and (c) are correct

Q.

Which one of the following statements can best explain the term critical concentration of an essential element?

1. Essential element concentration below which plant growth is retarded.

2. Essential element concentration below which plant growth is faster.

3. Essential element concentration below which plant remains in the vegetative phase.

4. Essential element concentration below which plant dies.

Q. The concentration of the essential element below which plant growth is retarded is termed as __ concentration.

Q. Long answer type questions.
Why were micronutrients discovered later than macronutrients? With one example each, mention the physiological role and deficiency disease caused by (i) nitrogen, (ii) phosphorus, (iii) copper, and (iv) iron.

Q.

Which one of the following statements can best explain the term critical concentration of an essential element?

1. Essential element concentration below which plant growth is retarded.

2. Essential element concentration below which plant growth is faster.

3. Essential element concentration below which plant remains in the vegetative phase.

4. Essential element concentration below which plant dies.

Q. Which of the following statements is incorrect?

1. Below critical concentration, nutrient levels limit plant growth
   
2. Beneficial elements include sodium, silicon, cobalt and selenium
3. Manganese toxicity induces deficiencies of iron and calcium
4. If there is a deficiency of mobile nutrients, the symptoms are first seen in newer parts of the plant

Q. The concentration of the essential element below which plant growth is retarded is termed as __ concentration.

Q. (a) Moderate decrease or increase of micronutrients causes deficiency and toxicity symptoms respectively.
(b) Excess of manganese causes toxicity of iron, calcium and molybdenum.
(c) A macronutrient is said to be toxic when present below a critical concentration.

1. Only (a) is correct
2. Only (b) is correct
3. (b) and (c) are correct
4. (a) and (c) are correct

Q. The growth rate is highest in

1. White light
2. None of the above
3. Green light
4. Red light

Q. short answer type questions.
Briefly describe the use of hydroponics to determine the mineral nutrients of a plant.

Q. Assertion :(A) Every plant can grow can grow in a suiatble mineral solution only (i.e, . without soil) Reason: Hydroponics do not helps in the identification elements anf deficiency symptoms of the plants

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. Which one is not a microelement for plants?

1. Cu
2. B
3. Zn
4. Cr

Q.

Which one of the following statements can best explain the term critical concentration of an essential element?

1. Essential element concentration below which plant remains in the vegetative phase.

2. Essential element concentration below which plant dies.

3. Essential element concentration below which plant growth is retarded.

4. Essential element concentration below which plant growth is faster.

Q. (a) Moderate decrease or increase of micronutrients causes deficiency and toxicity symptoms respectively.
(b) Excess of manganese causes toxicity of iron, calcium and molybdenum.
(c) A macronutrient is said to be toxic when present below a critical concentration.

1. Only (a) is correct
2. Only (b) is correct
3. (b) and (c) are correct
4. (a) and (c) are correct

Q. Assertion: Plant exhibits deficiency symptoms
Reason: It receives nutrients below critical concentration

1. Both assertion & reason are correct and the reason is the correct explanation of assertion.
2. Both assertion & reason are correct but the reason is not the correct explanation of assertion.
3. Assertion is correct but the reason is incorrect
4. Both assertion & reason are incorrect