Multiple interactions are involved in the formation of root nodules. The Rhizobium bacteria divide and form colonies. These get attached to the root hairs and epidermal cells. The root hairs get curled and are invaded by the bacteria. This invasion is followed by the formation of an infection threadRead more
Multiple interactions are involved in the formation of root nodules. The Rhizobium bacteria divide and form colonies. These get attached to the root hairs and epidermal cells. The root hairs get curled and are invaded by the bacteria. This invasion is followed by the formation of an infection thread that carries the bacteria into the cortex of the root. The bacteria get modified into rod-shaped bacteroides. As a result, the cells in the cortex and pericycle undergo division, leading to the formation of root nodules. The nodules finally get connected with the vascular tissues of the roots for nutrient exchange.
Rhizobium is a symbiotic bacteria present in the root nodules of leguminous plants. The basic requirements for Rhizobium to carry out nitrogen fixation are as follows: (a) Presence of the enzyme nitrogenase (b) Presence of leg-haemoglobin (c) Non-haem iron protein, ferrodoxin as the electron-carrierRead more
Rhizobium is a symbiotic bacteria present in the root nodules of leguminous plants.
The basic requirements for Rhizobium to carry out nitrogen fixation are as follows:
(a) Presence of the enzyme nitrogenase
(b) Presence of leg-haemoglobin
(c) Non-haem iron protein, ferrodoxin as the electron-carrier
(d) Constant supply of ATP
(e) Mg2+ions as co-factors
Rhizobium contains the enzyme nitrogenase – a Mo-Fe protein – that helps in the conversion of atmospheric free nitrogen into ammonia.
The reaction is as follows:
N₂ + 8e– + 8H+ + 16 ATP→ 2 NH₃ + H₂ + 16ADP + 16Pi
The Rhizobium bacteria live as aerobes under free-living conditions, but require anaerobic conditions during nitrogen fixation. This is because the enzyme nitrogenase is highly sensitive to molecular oxygen. The nodules contain leghaemoglobin, which protects nitrogenase from oxygen.
The absorption of soil nutrients by the roots of plants occurs in two main phases – apoplast and symplast. During the initial phase or apoplast, there is a rapid uptake of nutrients from the soil into the free spaces of plant cells. This process is passive and it usually occurs through trans-membranRead more
The absorption of soil nutrients by the roots of plants occurs in two main phases – apoplast and symplast.
During the initial phase or apoplast, there is a rapid uptake of nutrients from the soil into the free spaces of plant cells. This process is passive and it usually occurs through trans-membrane proteins and ion-channels.
In the second phase or symplast, the ions are taken slowly into the inner spaces of the cells. This pathway generally involves the expenditure of energy in the form of ATP.
Deficiency symptoms are morphological changes in plants, indicating nutrient deficiency. Deficiency symptoms vary from one element to another. The plant part in which a deficiency symptom occurs depends on the mobility of the deficient element in the plant. Elements such as nitrogen, potassium, andRead more
Deficiency symptoms are morphological changes in plants, indicating nutrient deficiency. Deficiency symptoms vary from one element to another. The plant part in which a deficiency symptom occurs depends on the mobility of the deficient element in the plant. Elements such as nitrogen, potassium, and magnesium are highly mobile. These elements move from the mature organs to the younger parts of a plant. Therefore, the symptoms for the deficiencies of these elements first appear in the older parts of the plant. Elements such as calcium and sulphur are relatively immobile. These elements are not transported out of the older parts of a plant. Therefore, the symptoms for the deficiencies of these elements first appear in the younger parts of the plant.
In plants, the deficiency of a nutrient can cause multiple symptoms. For example, the deficiency of nitrogen causes chlorosis and delayed flowering. In a similar way, the deficiency of a nutrient can cause the same symptom as that caused by the deficiency of another nutrient. For example, necrosis iRead more
In plants, the deficiency of a nutrient can cause multiple symptoms. For example, the deficiency of nitrogen causes chlorosis and delayed flowering.
In a similar way, the deficiency of a nutrient can cause the same symptom as that caused by the deficiency of another nutrient. For example, necrosis is caused by the deficiency of calcium, magnesium, copper, and potassium.
Another point to be considered is that different plants respond in different ways to the deficiency of the same nutrient.
Hence, to identify the nutrient deficient in a plant, all the symptoms developed in its different parts must be studied and compared with the available standard tables.
What are the steps involved in formation of a root nodule?
Multiple interactions are involved in the formation of root nodules. The Rhizobium bacteria divide and form colonies. These get attached to the root hairs and epidermal cells. The root hairs get curled and are invaded by the bacteria. This invasion is followed by the formation of an infection threadRead more
Multiple interactions are involved in the formation of root nodules. The Rhizobium bacteria divide and form colonies. These get attached to the root hairs and epidermal cells. The root hairs get curled and are invaded by the bacteria. This invasion is followed by the formation of an infection thread that carries the bacteria into the cortex of the root. The bacteria get modified into rod-shaped bacteroides. As a result, the cells in the cortex and pericycle undergo division, leading to the formation of root nodules. The nodules finally get connected with the vascular tissues of the roots for nutrient exchange.
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-11/biology/chapter-12/
What are the conditions necessary for fixation of atmospheric nitrogen by Rhizobium. What is their role in N₂ -fixation?
Rhizobium is a symbiotic bacteria present in the root nodules of leguminous plants. The basic requirements for Rhizobium to carry out nitrogen fixation are as follows: (a) Presence of the enzyme nitrogenase (b) Presence of leg-haemoglobin (c) Non-haem iron protein, ferrodoxin as the electron-carrierRead more
Rhizobium is a symbiotic bacteria present in the root nodules of leguminous plants.
The basic requirements for Rhizobium to carry out nitrogen fixation are as follows:
(a) Presence of the enzyme nitrogenase
(b) Presence of leg-haemoglobin
(c) Non-haem iron protein, ferrodoxin as the electron-carrier
(d) Constant supply of ATP
(e) Mg2+ions as co-factors
Rhizobium contains the enzyme nitrogenase – a Mo-Fe protein – that helps in the conversion of atmospheric free nitrogen into ammonia.
The reaction is as follows:
N₂ + 8e– + 8H+ + 16 ATP→ 2 NH₃ + H₂ + 16ADP + 16Pi
The Rhizobium bacteria live as aerobes under free-living conditions, but require anaerobic conditions during nitrogen fixation. This is because the enzyme nitrogenase is highly sensitive to molecular oxygen. The nodules contain leghaemoglobin, which protects nitrogenase from oxygen.
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-11/biology/chapter-12/
How are the minerals absorbed by the plants?
The absorption of soil nutrients by the roots of plants occurs in two main phases – apoplast and symplast. During the initial phase or apoplast, there is a rapid uptake of nutrients from the soil into the free spaces of plant cells. This process is passive and it usually occurs through trans-membranRead more
The absorption of soil nutrients by the roots of plants occurs in two main phases – apoplast and symplast.
During the initial phase or apoplast, there is a rapid uptake of nutrients from the soil into the free spaces of plant cells. This process is passive and it usually occurs through trans-membrane proteins and ion-channels.
In the second phase or symplast, the ions are taken slowly into the inner spaces of the cells. This pathway generally involves the expenditure of energy in the form of ATP.
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-11/biology/chapter-12/
Why is that in certain plants deficiency symptoms appear first in younger parts of the plant while in others they do so in mature organs?
Deficiency symptoms are morphological changes in plants, indicating nutrient deficiency. Deficiency symptoms vary from one element to another. The plant part in which a deficiency symptom occurs depends on the mobility of the deficient element in the plant. Elements such as nitrogen, potassium, andRead more
Deficiency symptoms are morphological changes in plants, indicating nutrient deficiency. Deficiency symptoms vary from one element to another. The plant part in which a deficiency symptom occurs depends on the mobility of the deficient element in the plant. Elements such as nitrogen, potassium, and magnesium are highly mobile. These elements move from the mature organs to the younger parts of a plant. Therefore, the symptoms for the deficiencies of these elements first appear in the older parts of the plant. Elements such as calcium and sulphur are relatively immobile. These elements are not transported out of the older parts of a plant. Therefore, the symptoms for the deficiencies of these elements first appear in the younger parts of the plant.
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-11/biology/chapter-12/
If a plant shows a symptom which could develop due to deficiency of more than one nutrient, how would you find out experimentally, the real deficient mineral element?
In plants, the deficiency of a nutrient can cause multiple symptoms. For example, the deficiency of nitrogen causes chlorosis and delayed flowering. In a similar way, the deficiency of a nutrient can cause the same symptom as that caused by the deficiency of another nutrient. For example, necrosis iRead more
In plants, the deficiency of a nutrient can cause multiple symptoms. For example, the deficiency of nitrogen causes chlorosis and delayed flowering.
In a similar way, the deficiency of a nutrient can cause the same symptom as that caused by the deficiency of another nutrient. For example, necrosis is caused by the deficiency of calcium, magnesium, copper, and potassium.
Another point to be considered is that different plants respond in different ways to the deficiency of the same nutrient.
Hence, to identify the nutrient deficient in a plant, all the symptoms developed in its different parts must be studied and compared with the available standard tables.
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-11/biology/chapter-12/