NEET Questions - Mineral Nutrition

 

1. NEET Queastions

Que- Which is essential for the growth of root tip?

A

$C{a}^{2+}$ 

B

$M{n}^{2+}$ 

C

$Z{n}^{2+}$ 

D

$F{e}^{2+}$ 

Medium

NEET

Correct option is

A

$C{a}^{2+}$ 

• Calcium ions are used in new cell walls synthesis, particularly the middle lamellae that separate newly divided cells.
•  It is also used in the mitotic spindle during cell division and calcium deficiency causes necrosis of young meristematic regions, such root and leaf tips, the sites of rapid cell division and wall formation. 

Therefore, the correct answer is option A.

Que- The first stable product of fixation of atmospheric nitrogen in leguminous plants is

A

$N{O}_2^{-}$

B

Ammonia

C

$N{O}_3^{-}$

D

Glutamate

Medium

NEET

Correct option is

B

Ammonia

The nitrogen produces diimide (N${}_2$H${}_2$), hydrazine (N${}_2$H${}_4$) and then ammonia, which is the stable product. Thus, the correct answer is option (B), 'Ammonia'.

Que-Deficiency symptoms of nitrogen and potassium are visible first in

A

Senescent leaves

B

Young leaves

C

Roots

D

Buds

Medium

NEET

Correct option is

A

Senescent leaves

Generally, nutrient deficiency in the plant occurs, when a nutrient is insufficient in the growth medium and / or cannot be absorbed and assimilated by the plants due to unfavorable environmental conditions. The characteristic deficiency symptom of nitrogen is the appearance of uniform yellowing of leaves including the veins, this being more pronounced on older leaves. The leaves become stiff and erect. In dicotyledonous crops the leaves detach easily under extreme deficiency condition. Cereal crops show characteristics 'V' shaped yellowing at the tip of lower leaves. Under potassium stress condition, yellowing of leaves starts from the tips or margins of leaves extending towards the center of leaf base. These yellow parts become necrotic (dead spots) with leaf curling.

Que-Which one of the following is not an essential mineral element for plants

A

Iron

B

Manganese

C

Cadmium

D

Phosphorus

Hard

NEET

Correct option is

C

Cadmium

E. Epstein defined two criteria for an element to be essential for plant growth: in its absence the plant is unable to complete a normal life cycle; or that the element is part of some essential plant constituent or metabolite. This is in accordance with Liebig's law of the minimum. There are 14 essential plant nutrients. Plants must obtain the following mineral nutrients from the growing media: 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).

Que-Which one of the following is essential for photolysis of water?

A

Manganese

B

Zinc

C

Copper

D

Boron

Medium

NEET

Correct option is

A

Manganese

Photolysis is part of the light-dependent reactions of photosynthesis. The general reaction of photosynthetic photolysis can be given as:
H2A + 2 photons (light) 2 e + 2 H+ + A
The chemical nature of "A" depends on the type of organism. In purple sulfur bacteria, hydrogen sulfide (H${}_2$S) is oxidized to sulfur (S). In oxygenic photosynthesis, water (HO) serves as a substrate for photolysis resulting in the generation of diatomic oxygen (O${}_2$). This is the process which returns oxygen to Earth's atmosphere. Photolysis of water occurs in the thylakoids of cyanobacteria and the chloroplasts of green algae and plants.
Manganese is a micro element required by plants, obtained in the form of manganous ions. It is an important ion in photolysis. It also helps by activating several other enzymes which promotes photolysis.

So, the correct answer is 'Manganese'

Que- Natural reservior of phosphorus is

A

Sea water

B

Animal bones

C

Sedimentary rocks

D

Fossils

Hard

NEET

Correct option is

C

Sedimentary rocks

Phosphorous is present in the form of phosphates in rocks. As the rocks get weathered due to various environmental factors, some amount of these phosphates get dissolved in the soil and are absorbed by the plants.

Hence, the natural reservoir of phosphorous is sedimentary rocks.

So, the correct answer is 'Sedimentary rocks'.

Que-In which of the following forms is iron absorbed by plants?

A

Free element

B

Ferric

C

Both ferric and ferrous

D

Ferrous

Medium

NEET

Correct option is

B

Ferric

• Iron is the most abundant mineral ion required by the plant. It is absorbed in ferrous and ferric form from the rhizosphere of the plant. 
• Fe${}^{2+}$ (ferrous) form is relatively soluble but is readily oxidized to Fe${}^{3+}$ (ferric) at the junction of the protoxylem and the metaxylem, chelated by citrate, and then transported in the metaxylem to the other parts of the plant. 

So, the correct answer is 'Ferric'.

Que- In which of the following, all three are macronutrients?

A

Boron, zinc, manganese

B

Iron, copper, molybdenum

C

Molybdenum, magnesium, manganese

D

Nitrogen, potassium, phosphorus

Medium

NEET

Correct option is

D

Nitrogen, potassium, phosphorus

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. 

The oxygen evolved during photosynthesis comes from water molecules. Which one of the following pairs of elements is involved in this reaction?

A

Magnesium and Chlorine

B

Manganese and Chlorine

C

Manganese and Potassium

D

Magnesium and Molybdenum

Hard

NEET

Correct option is

B

Manganese and Chlorine

The breakdown of water molecules into hydrogen and oxygen in the presence of light, during the light reaction of photosynthesis is called photolysis of water. The micronutrients manganese and chlorine are involved in the photolysis of water.

The other options given in the question have following functions:

• Magnesium- It is component of chlorophyll and activator of enzymes involved in respiration and photosynthesis.

• Potassium- It is required as a cofactor for many enzymes and maintains membrane permeability, turgidity of cells, anion-cation balance in cells.

• Molybdenum- It is component of enzyme nitrate reductase and is involved in nitrogen metabolism.

So, the correct answer is 'Manganese and Chlorine'

Leguminous plants are able to fix atmospheric nitrogen through the process of symbiotic nitrogen fixation. Which one of the following statements is not correct during this process of nitrogen fixation?

A

Nitrogenase is insensitive to oxygen.

B

Leghaemoglobin scavenges oxygen and is pinkish in colour.

C

Nodules act as sites nitrogen fixation.

D

The enzyme nitrogenase catalyses the conversion of atmospheric $N_2$ to $N{H}_3$.

Hard

NEET

Correct option is

A

Nitrogenase is insensitive to oxygen.

1. The enzyme nitrogenase is sensitive to molecular oxygen. The enzyme requires anaerobic condition during nitrogen fixation, but live as aerobes under free-living conditions.

2. Leg-haemoglobin provides anaerobic condition to the enzyme nitrogenase. It protects the enzyme from oxygen. It scavenges oxygen and is pinkish in colour.

3. As nodules contain necessary biochemical components so that helps in fixing atmospheric nitrogen to ammonia. They act like sites of nitrogen fixation.

4. The enzyme nitrogenase catalyses the conversion of atmospheric nitrogen to ammonia.  It requires 8 ATP.  The energy obtained from the respiration of the host plant.

Thus, the correct answer is option A.

Thiobacillus is a group of bacteria helpful in carrying out.

A

Nitrogen fixation

B

Chemoautotrophic fixation

C

Nitrification

D

Denitrification

Medium

NEET

Correct option is

D

Denitrification

Thiobacillus denitrificans is chemolithoautotrophic bacteria that denitrifies nitrate during oxidation of FeS${}_x$ compounds.

So, the correct answer is 'Denitrification

The product(s) of reaction catalyzed by nitrogenase in root nodules of leguminous plants is/are

A

Nitrate alone

B

Ammonia and oxygen

C

Ammonia and hydrogen

D

Ammonia alone

Correct option is

C

Ammonia and hydrogen

During the nitrogen fixation process, the enzyme nitrogenase converts the atmospheric nitrogen into ammonia and hydrogen gas.

Thus, the correct answer is (C).

Medium

NEET