Assertion: All nitrogen fixing organisms are bacteria.
Reason: Only bacteria can have mutualistic relationship with roots of plants.
1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.
An element that is labeled as ‘essential’ for plants is characterized by all the following except:
1. Its deficiency cannot be met by supplying some other element
2. It allows normal vegetative growth but does not allow seed set, if absent
3. Its requirement must be specific
4. It must be directly involved in the metabolism of the plant
The minimum amount of requirement for an element to be classified as a macronutrient for plants is:
1. 5 mmole of dry matter
2. 10 mmole of dry matter
3. 20 mmole of dry matter
4. 40 mmole of dry matter
Which of the following element required by the plants is a micronutrient?
1. Phosphorus | 2. Sulphur |
3. Iron | 4. Magnesium |
Identify the incorrect statement amongst the following:
1. Phosphorus is obtained by the plants from the soil in the form of phosphates
2. Nitrogen is obtained from the soil in the form of nitrates , nitrites and ammonium salts
3. Sulphur is mainly obtained by plants as sulphur dioxide by foliar absorption
4. Boron is absorbed in the form of borate ions
is an activator of the enzyme:
1. RuBisCO | 2. PEP carboxylase |
3. Nitrogenase | 4. Alcohol dehydrogenase |
An essential element categorized in elements that can alter the osmotic potential of a cell will be:
1. Nitrogen | 2. Phosphorus |
3. Molybdenum | 4. Potassium |
Identify the element that is not obtained by terrestrial plants primarily from soil?
1. Potassium | 2. Nitrogen |
3. Phosphorus | 4. Carbon |
A plant requires magnesium mainly for:
1. DNA replication | 2. Synthesizing enzymes |
3. Synthesizing hormones | 4. Synthesizing chlorophyll |
Which of the following elements is a constituent of vitamins such as thiamine, biotin and Coenzyme A?
1. Calcium | 2. Sulfur |
3. Iron | 4. Phosphorus |