Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

Molybdenum is involved in plant metabolism in Nitrate reduction.
Molybdenum nutrition is an essential component of healthy plant growth. Molybdate which is the predominant form available to plants is required at very low levels where it is known to participate in various redox reactions in plants as part of the pterin complex Moco.
Molybdenum (Mo), an essential micronutrient, plays an important role in nitrogen (N) metabolism and protein synthesis in plants. During symbiotic N fixation, Mo acts as a cofactor for nitrogenase enzymes to catalyze the redox reaction to convert elemental N into ammonium (NH₄⁺) ions.

The formation of gametophyte directly from sporophyte without meiosis is Apospory.
Apospory is the development of 2n gametophytes, without meiosis and spores, from vegetative, or nonreproductive, cells of the sporophyte.
It develops in pteridophytes that have a mineral nutrition shortage due to insufficient minerals in the soil.

The sensitivity of ELISA lies in the range of 1 - 10 ng/l.
The typical detection range for an ELISA is 0.1 to 1 fmole or 0.01 ng to 0.1 ng, with sensitivity dependent upon the particular characteristics of the antibody-antigen interaction.
ELISAs tend to be the most sensitive immunoassays due to the binding characteristics of the antibodies and the amplification or different read-out systems used.

Tangro disease of rice is spread by Nephotettix virescens.
Tungro disease viruses are transmitted from one plant to another by leafhoppers that feed on tungro-infected plants. The most efficient vector is the green leafhopper. Leafhoppers can acquire viruses from any part of the infected plant by feeding on it, even for a short time.
It is transmitted by leafhoppers only in the presence of RTSV. The major vector is the rice green leafhopper, Nephotettix virescens, and it can also be transmitted by some other leafhopper species such as N. nigropictus, N.

The term hypersensitive response is coined by Stakman.
Hypersensitive response (HR) is a mechanism used by plants to prevent the spread of infection by microbial pathogens. HR is characterized by the rapid death of cells in the local region surrounding infection and it serves to restrict the growth and spread of pathogens to other parts of the plant.
HR is commonly thought of as an effective defence strategy against biotrophic plant pathogens, which require living tissue to gain nutrients.

A nitrogen-fixing enzyme found in root nodules is Nitrogenase.
Nitrogenases are enzymes that are produced by certain bacteria, such as cyanobacteria (blue-green bacteria) and rhizobacteria.
These enzymes are responsible for the reduction of nitrogen (N₂) to ammonia (NH₃). Nitrogenases are the only family of enzymes known to catalyze this reaction, which is a key step in the process of nitrogen fixation.

The sink is related to the transport of minerals.
The points of sugar delivery, such as roots, young shoots, and developing seeds, are called sinks.
Sinks include areas of active growth (apical and lateral meristems, developing leaves, flowers, seeds, and fruits) or areas of sugar storage (roots, tubers and bulbs).

Maximum O₂ evolution occurs from Marine phytoplankton.
Phytoplankton is the autotrophic component of the plankton community and a key part of ocean and freshwater ecosystems.
In a balanced ecosystem, they provide food for a wide range of sea creatures. Phytoplankton, also known as microalgae, are similar to terrestrial plants in that they contain chlorophyll and require sunlight to live and grow.
They account for about half of the global photosynthetic activity and at least half of the oxygen production, despite amounting to only about 1% of the global plant biomass.

The target disease of Blockade is Downy mildew.
Downy mildew refers to any of several types of oomycete microbes that are obligate parasites of plants.
Initial symptoms include large, angular or blocky, yellow areas visible on the upper surface. As lesions mature, they expand rapidly and turn brown.

In photosynthesis, photolysis of water is used in the Reduction of NADP⁺.
It acts as the primary electron acceptor for the photosystems. As part of the electron transport chain, it manufactures ATP. As a component of photosystem II, it catalyzes the hydrolysis of water. It is reduced and then carries electrons to the Calvin cycle.
The electrons travel through the chloroplast electron transport chain to photosystem I (PSI), which reduces NADP⁺ to NADPH.