Question 1

In which of the following, all three are macronutrients?

Accepted Answer

From the given options, Option D has a better answer with macro nutrients - Nitrogen, Potassium and Phosphorus.All other options have only micronutrients and thus 'D' turns the correct answer. The primary macronutrients: nitrogen (N), phosphorus (P), potassium (K) the three secondary macronutrients: calcium (Ca), sulfur (S), magnesium (Mg) the micronutrients/trace minerals: boron (B), chlorine (Cl), manganese (Mn), iron (Fe), zinc (Zn), copper (Cu), molybdenum (Mo), nickel (Ni). In relatively large amounts, the soil supplies nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur; these are often called the macronutrients. In relatively small amounts, the soil supplies iron, manganese, boron, molybdenum, copper, zinc, chlorine, and cobalt, the so-called micronutrients. Nutrients must be available not only in sufficient amounts but also in appropriate ratios.So, the correct answer is option D.

Question 2

Which element is essential for photolysis of water?

Accepted Answer

Photolysis term denotes light dependent split of water leading to oxidation of water. This process occurs in thylakoid lumen in association with photosystem II. Mineral ions required for photolysis of water are manganese, calcium and chlorine. Oxygen is released as the byproduct of photosynthesis in the photolysis process.

Question 3

Match the columns and choose the correct option.III(a)Magnesium$1$.Alcohol dehydrogenase(b)Molybdenum$2$.Phosphoenol pyruvate(c)Zinc$3$.Nitrogenase

Accepted Answer

Magnesium is present in phosphoenol pyruvate enzyme.Molybdenum is a key element of nitrogenase as Mo-Fe protein.Zinc is an activator of alcohol dehydrogenase enzyme.Thus, the correct answer is option A.

Question 4

Which of the following is not a criterion for essentiality of an element?

Accepted Answer

Arnon and Stout (1939) proposed criteria for knowing the essentiality of an element. There are:(i) It is indispensable for the growth of plants.(ii) The element is directly involved in the metabolism of plants.(iii) A plant is unable to complete its vegetative or reproductive phase in the absence of the element.(iv) The element cannot be replaced by any other element.(v)&#10; The absence or deficiency of the element produces disorders. These disorders are a direct result of the lack or deficiency of the element. So, the correct answer is 'Indirectly involved in plant metabolism'.

Question 5

How many ATP molecules are needed to produce $4$ moles of $NH_3$ without release of the $H_2$ during symbiotic $N_2$ fixation by Rhizobium leguminosarum ________________.

Accepted Answer

Biological nitrogen fixation can be represented by the following equation, in which two moles of ammonia are produced from one mole of nitrogen gas, at the expense of 16 moles of ATP and a supply of electrons and protons.N$_2$ + 8H+ + 8e- + 16 ATP$\rightarrow$ 2NH$_3$ + H$_2$ + 16ADP + 16 PiSo, for 4 mole of ammonia, 32 ATP molecules are required.So, the correct option is '32'.

Question 6

Bacteria present in root nodules of the leguminous plants are

Accepted Answer

Leguminous plants belong to the family Fabaceae. These plants have a symbiotic association with the soil bacteria called the Rhizobium, that live in their roots, forming root nodules and fix atmospheric nitrogen into the nitrates and nitrites for the plants and in turn, the plants provide the nutrition to the bacteria.A. Rhizobium is the nitrogen-fixing bacteria living in symbiotic association with leguminous plants.B. Lactobacillus is used in curdling of the milk.C. Cyanobacteria are free-living, photosynthetic, nitrogen-fixing bacteriaD. Azotobacter is free-living, nitrogen-fixing bacteria.Hence, the correct answer is 'Rhizobium'.

Question 7

In the initial phase of mineral ion absorption, there is a rapid uptake of ions into ______ space of cells. Ions absorbed in this phase are ______ exchangable. It is _____ uptake as it ______ the expenditure of metabolic energy.

Accepted Answer

In the principal stage, an underlying fast take-up of particles into the 'free space' or 'space' of cells the apoplast, is detached.So, the correct option is 'outer, freely, passive, does not require'.

Question 8

Free living nitrogen fixing aerobic bacterium is

Accepted Answer

Rhodospirillum is a free-living nitrogen-fixing anaerobic bacteria.Anabaena & Nostoc are symbiotic nitrogen-fixing cyanobacteria.Beijerinikia is free-living nitrogen-fixing aerobic bacteria.Rhizobium is symbiotic nitrogen-fixing aerobic bacteria but fixes nitrogen in anaerobic conditions.Hence the correct answer is D.

Question 9

Which one of the following elements is not an essential micronutrient for plant growth?

Accepted Answer

Plants require seventeen essential mineral elements which can be grouped into two classes based on the amount required- Macronutrients (required in large amount) and micronutrient (required in small amounts). The essential macronutrients are carbon, hydrogen, oxygen, nitrogen, phosphorous, potassium, sulphur, magnesium, calcium and essential micronutrients are iron, molybdenum, boron, chlorine, copper, zinc, nickel and manganese.

Question 10

Which of the following is not caused by deficiency of mineral nutrition?

Accepted Answer

Necrosis, chlorosis and shortening of internodes are important deficiency symptoms, which are caused due to deficiency of mineral elements in plants. Etiolation means growth of plants in absence of sunlight. As sunlight is an important requirement for chlorophyll biosynthesis. These plants will be pale in color and have thin elongated internodes.so, the correct answer is 'Etiolation'