Tag: a seeds tells a farmer's story

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Questions Related to a seeds tells a farmer's story

Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

A red pigment present in the root nodules of leguminous plants is known as

  1. Phycoerythrin

  2. Bacteriochlorophyll

  3. Leghaemoglobin

  4. Bacterioviridin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Leguminous plants are in symbiotic association with nitrogen-fixing bacteria like Rhizobium. These bacteria invade root hairs of leguminous plants and forms root nodules in which they fix nitrogen. A red pigment present in the root nodules of leguminous plants is known as leghaemoglobin. Leghaemoglobin is an oxygen-carrier molecule.  It protects nitrogen-fixing enzyme nitrogenase from the side effect of oxygen as the enzyme is highly sensitive to oxygen.

Thus, the correct answer is 'Leghaemoglobin.'

Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Which of the following plants are used as green manure in crop field and in sandy soils?

  1. Crotalaria juncea and Alhagi camelorum

  2. Calotropis procera and Phyllanthus niruri

  3. Saccharum munja and Lantana camara

  4. Dichanthium annulatum and Azolla nilotica
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Crotalaria juncea and Alhagi camelorum are used as green manure in crop fields and sandy soils because these plants, when grown, replenish the soil with sufficient nutrients and nitrogen content after its usage by the crop plant.

So, the correct option is 'Crotalaria juncea and Alhagi camelorum'.

Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Leghaemoglobin functions as

  1. Oxygen scavenger

  2. Nitrogen scavenger
  3. $CO _2$ scavenger

  4. Hydrogen carrier
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The root nodules of the leguminous plants contain an oxygen-binding heme protein called leghemoglobin. It is present in the cytoplasm of infected nodule cells at high concentrations. The function of  leghemoglobin is to help transport oxygen to the respiring symbiotic bacterial cells in a manner analogous to hemoglobin transporting oxygen to respiring tissues in animals. It has a high affinity for oxygen (approximately, ten times higher than the ß chain of human hemoglobin). Thus, it acts as a oxygen scavenger.
Hence, the correct answer is option (A).

Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Identify the role of lectins in formation of root nodules in legumes.

  1. Formation of shepherd's crook

  2. Recognition of compatible Rhizobium by host

  3. Formation of peribacterial membrane

  4. Formation of infection thread
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Lectins are sugar-binding proteins that play a key role in the recognition and attachment of compatible Rhizobium bacteria to the root hairs of host leguminous plants.

Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Function of red pigment leghaemoglobin present in root nodules of leguminous plants is to regulate

  1. $CO _2$ supply in cells

  2. Mo supply to cells
  3. $O _2$ supply to cells

  4. Production of phenolic compounds
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The root nodules of the leguminous plants contain an oxygen-binding heme protein called leghemoglobin. It is present in the cytoplasm of infected nodule cells at high concentrations. This leghemoglobin has a high affinity for oxygen, (approximately, ten times higher than the ß chain of human hemoglobin). Its function is to help transport oxygen to the respiring symbiotic bacterial cells in a manner analogous to hemoglobin transporting oxygen to respiring tissues in animals. Thus, it regulates oxygen supply to the cells.
Thus, the correct answer is option (C). 
Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Leghaemoglobin takes part in

  1. Energy release

  2. Stimulating growth of rhizobium
  3. $N _2$ absorption
  4. Protecting nitrogenase from $O _2$

  5. Supply of oxygen
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The root nodules contain pink colored pigment contains a protein called leg-hemoglobin.

Leg-haemoglobin acts as an oxygen scavenger and provides anaerobic conditions to the bacteria.
So the correct answer is 'protecting nitrogenase from oxygen'

Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Leghaemoglobin occurs in

  1. Coralloid root

  2. BGA

  3. Around bacterial infections of root nodules

  4. Mycorrhiza
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Leghaemoglobin is an oxygen carrier found in the nitrogen fixing root nodules of leguminous plants. Rhizobium is a free living bacteria that can fix atmospheric nitrogen.

Steps involved in nodule formation are
1.Rhizobium bacteria contact a susceptible root hair.
2.After this they will divide near it.
3.Then Rhizobium infects the root hair causing it to curl.
4.Infected thread carries the bacteria to the inner cortex.
5.The bacteria get modified into rod shaped bacteroids and cause inner cortical and pericycle cells to divide.
6.Division lead to nodule formation.
So the correct answer is 'Around bacterial infections of root nodules'

Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Apart from bacteria, which of the following microbes help in nutrient replenishment in the soil?

  1. Protozoa

  2. Fungi

  3. Virus

  4. Lichens
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Protozoa play a major role in replenishing nutrients in the soil. Protozoa have a lower concentration of nitrogen in their cells than the bacteria they eat. Therefore, they obtain and utilize the amount of nitrogen needed and release the excess in the form of ammonium, thereby making it available for use by plants and other soil organisms.   

So the correct option is 'Protozoa'

Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Which of the following helps the plant to absorb nitrogen from the environment?

  1. Algae

  2. Lichens

  3. Rhizobium

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Plants are not capable of fixing nitrogen on their own, but need it in one or the other form to make proteins and amino acids. Legumes form root nodules, when they exist in a symbiotic relationship with 'Rhizobia' and therefore, have high levels of nitrogen available to them. These soil bacteria (e.g., Rhizobium, Mesorhizobium, Sinorhizobium) fix the atmospheric nitrogen or dinitrogen, into inorganic compounds, like ammonium, which is then converted into amino acids, which the plants can utilize.

So the correct option is 'Rhizobium'