Nitrogenase enzyme converts
Nitrogenases are enzymes that are produced by certain bacteria, such as cyanobacteria (blue-green algae). These enzymes are responsible for the reduction of nitrogen (N2) to ammonia (NH3).
Insectivorous plants are usually adapted to
The insectivorous plants are the carnivorous plants which feed on the insects. These plants have adapted to grow in the extreme conditions of the soil such as acidic pH. Generally, these plants are known to grow in the soil which is deficient in the mineral nutrients due to the presence of acid. The plant can grow in the soil which have low levels of nitrogen.
Name the elements which occur in a nucleic acid molecule.
The phosphate groups allow the nucleotides to link together, creating the sugar-phosphate backbone of the nucleic acid while the nitrogenous bases provide the letters of the genetic alphabet. These components of nucleic acids are constructed from five elements: carbon, hydrogen, oxygen, nitrogen, and phosphorous.
Name the element which plays an important role in biological nitrogen fixation.
Molybdenum as well as Phosphorous play important role in BNF. Nitrogen fixation needs an enzyme called nitrogenase. The nitrogenase enzyme has two kinds of proteins viz. Iron Protein, and Iron-Molybdenum protein. Similarly, Leguminous plants that are NZ fixing will usually require more P than similar plants supplied fertilizer N. Nodules are an important P sink, and commonly have the highest concentration of that element in the plant. This is because of the high energy cost of N2 fixation and the cost of building and maintaining functioning nodules.
Which one of the following is a wrong statement ?
Ozone (O3) is an isotope of oxygen which exists in so called ozone layer at a height of about 15-60 km in the middle and upper stratosphere and lower mesosphere. This ozone layer absorbs UV-rays of longer wavelength and protects life on Earth from damaging effects of these radiations. Ozone in the lower atmosphere (troposphere) is regarded as a pollutant.
Which one of the following microbes forms a symbiotic association with plants and helps them in their nutrition.
Several species of Glomus, including G. aggregatum, are cultured and sold as mycorrhizal inoculant for agricultural soils. Being endomycorrhiza, it helps the plants in the absorption of nutrients especially phosphorus from soil.
Conversion of ammonia into nitrates through Nitrosomonas is called
Nitrosomonas convert ammonia into nitrates by a process called nitrification. It is performed in two steps – nitrite formation and nitrate formation.
Denitrification is carried out by
Denitrification is carried out by a large variety of heterotrophic bacteria, the most common ones thought to be Clostridium, Pseudomonas and Bacillus.
Function of leghaemoglobin (a red pigment) in root nodules of leguminous plants is to regulate
In plants colonised by Rhizobium, such as alfalfa or soybeans, the presence of oxygen in the root nodules would reduce the activity of the oxygen-sensitive nitrogenase, which is an enzyme responsible for the fixation of atmospheric nitrogen. Leghemoglobin buffers the concentration of free oxygen in the cytoplasm of infected plant cells to ensure the proper function of root nodules. Leghemoglobin has a high affinity for oxygen (Km ~ 0.01 µM), about ten times higher than the β chain of human hemoglobin. This allows an oxygen concentration that is low enough to allow nitrogenase to function, but high enough that it can provide the bacteria with oxygen for respiration.
During nitrification, which bacteria convert ammonia to nitrites?
The nitrification process requires the mediation of two distinct groups: bacteria that convert ammonia to nitrites (Nitrosomonas, Nitrosospira,Nitrosococcus, and Nitrosolobus) and bacteria that convert nitrites (toxic to plants) to nitrates (Nitrobacter,Nitrospina, and Nitrococcus).