Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

In C₄ plants, initial carbon dioxide fixation occurs in the chloroplasts of Spongy parenchyma.
C₄ carbon fixation is one of three known photosynthetic processes of carbon fixation in plants.
C₄ leaves generally differentiate into two partially isolated compartments called mesophyll cells and bundle-sheath cells. CO₂ is initially fixed in the mesophyll cells by the enzyme PEP carboxylase which reacts with the three carbon. Mesophyll cells are parenchymatous cells.
The CO₂ is fixed by RuBisCo to produce phosphoglycerate (PGA) while the pyruvate is transported back to the mesophyll cell, together with about half of the phosphoglycerate (PGA).

The passage of minerals from topsoil to subsoil through seepage of water is known as Leaching.
Leaching is the loss of water-soluble plant nutrients from the soil, due to rain and irrigation. Soil structure, crop planting, type and application rates of fertilizers, and other factors are taken into account to avoid excessive nutrient loss.
Leaching is a natural environmental concern when it contributes to groundwater contamination.

Plants exchange water with the environment through structures of two cell Stomata.
Stomata are cell structures in the epidermis of tree leaves and needles that are involved in the exchange of carbon dioxide and water between plants and the atmosphere.
The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the stomatal opening.

Can is a nitrate fertilizer and ammonium fertilizer.
Calcium ammonium nitrate or CAN, also known as nitro-limestone or nitrochalk, is a widely used inorganic fertilizer, accounting for 4% of all nitrogen fertilizers.
CAN is a nitrogen fertilizer that contains equal parts of fast acting nitrate-nitrogen and longer lasting ammonium-nitrogen. This ensures a more continuous nitrogen supply to the crop and thus better efficiency of use, and also makes it suitable for unseasonal application during summer or winter.

Organelles involved in photorespiration are Mitochondria peroxisomes and chloroplasts.
Plant mitochondria also serve a unique role in photorespiration, the conversion of glycine to serine, CO₂ and NH₃. This respiratory organelle has a major role in photosynthetic carbon and nitrogen metabolism in the leaves of C₃ plants.
The most prominent role of peroxisomes in photosynthetic plant tissues is their participation in photorespiration, a process also known as the oxidative C₂ cycle or the oxidative photosynthetic carbon cycle.

In sugarcane, ¹⁴CO₂ is fixed in malic acid. The enzyme is PEP carboxylase.
Phosphoenolpyruvate carboxylase is an enzyme in the family of carboxy-lyases found in plants and some bacteria that catalyzes the addition of bicarbonate (HCO₃^-) to phosphoenolpyruvate (PEP) to form the four-carbon compound oxaloacetate and inorganic phosphate.
This reaction is used for carbon fixation in CAM and C₄ organisms, as well as to regulate flux through the citric acid cycle in bacteria and plants.

Certification, Inspection and Quarantine strategies involve the exclusion of pathogens.
This principle is defined as any measure that prevents the introduction of a disease-causing agent into a region, farm, or planting.
Quarantine is a restriction on the movement of people or goods so that spread of disease can be prevented. so a period when a person, plant or animal that has or may have an infectious disease must be kept away in isolation from others.
To facilitate safe global trade in agriculture by assisting the producers and exporters by providing a technically competent and reliable phytosanitary certificate system to meet the requirements of trading partners.

Oxathiin is not an inorganic fungicide from the given options.
It is a six-membered, unsaturated heterocycle containing four carbon atoms, one sulphur, one oxygen atom and two double bonds.
The current study shows that certain oxathiin carboxamides are selectively active against particular mutated SDCs of U. maydis and A. nidulans.

The cell wall of Chytridimycetes class of fungi is composed of Glucan + Ch.itin.
Chytridiomycetes also known as Cytrids is the major class of the phylum Chytridiomycota, which contains several parasitic species.
Chytrids lack a true mycelium. The thallus is irregularly shaped and the cell wall, as in other true fungi, contains chitin and glucans. Unlike other true fungi, however, chytrids produce motile zoospores that possess a single, posterior, whiplash flagellum.

The symptoms of powdery mildew of peas (caused by Erysiphe polygoni) first appear on Leaves.
Powdery mildews are easily recognized by the white, powdery growth of the fungus on infected portions of the plant host.
The powdery appearance results from the superficial growth of the fungus as thread-like strands (hyphae) over the plant surface and the production of chains of spores.
Symptoms consist of a light, greyish, powdery growth on the leaves, pods, and occasionally on the stems.