Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

Chytridiomycetes fungi have single posterior flagella.
Chytridiomycetes is the major class of the phylum Chytridiomycota, which contains several parasitic species.
A common characteristic of chytrid fungi is that they propel themselves with a single posterior flagellum.

Photosynthesis is a process in which CO₂ is reduced.
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy, through cellular respiration.
Photosynthesis occurs in two stages. In the first stage, light-dependent reactions or light reactions capture the energy of light and use it to make the hydrogen carrier NADPH and the energy-storage molecule ATP.
During the second stage, the light-independent reactions use these products to capture and reduce carbon dioxide.

The six kingdoms system was given by Carl Woese.
Six Kingdoms is a scheme of classifying organisms into six kingdoms, It is Proposed by Carl Woese.
It comprises 3 domains - Archae, Bacteria, and Eukarya. These domains are further classified into kingdoms - Archaebacteria, Eubacteria, Protista, Fungi, Plantae and Animalia.

The C₄ plants are different from the C₃ plants with reference to the substance that accepts CO₂ in carbon assimilation.
In C₄ plants, CO₂ is assimilated by condensing with PEP, with the help of the PEPCase enzyme to yield the first stable product, four carbon compound OAA.
Whereas In the C₃ plants, CO₂ is assimilated by condensing with RuBP with the help of RuBisCO enzyme to yield the first stable product, the three-carbon compound PGA.

The bitter rot of apples is caused by Colletotrichum gloeosporoides.
Bitter rot on apple and pear fruit is caused by the pathogenic fungi in the Colletrotrichum genus, specifically those species in the C. acutatum and C. gleosporioides species complexes.
It is identified by sunken circular lesions with conical intrusions into the apple flesh that appear V-shaped when the apple is cut in half through the center of the lesion. It is one of the most devastating diseases of apple fruit in regions with warm wet weather.

The outbreak of coffee rust in 1870 was marked in Srilanka.
Hemileia vastatrix is a multicellular basidiomycete fungus that causes coffee leaf rust (CLR), a disease affecting the coffee plant.
Coffee serves as the obligate host of coffee rust, that is, the rust must have access to and come into physical contact with coffee to survive.
Rust was first reported in the major coffee-growing regions of Sri Lanka. The causal fungus was first fully described by the English mycologist Michael Joseph Berkeley.

The bacterium containing yellow pigment is Xanthomonas.
Xanthomonadins are a unique class of carotenoid-like pigments produced by members of the phytopathogenic genus Xanthomonas.
These pigments are brominated, aryl-polyene, yellow, water-insoluble pigments that are associated exclusively with the outer membrane of the bacterial cell wall.

In Maize, mesophyll cells perform photosynthetic cycle C₄.
C₄ carbon fixation is one of three known photosynthetic processes of carbon fixation in plants. Like many other plants, maize is one of the C₄ plants, where the photosynthetic cycle is performed in mesophyll cells.
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 the three-carbon phosphoenolpyruvate (PEP) with CO₂ to form the four-carbon oxaloacetic acid (OAA).

Soft rot of squash is caused by Choanephora parasitica.
Choanephora is a genus of Zygomycota fungi. Choanephora species are known as plant pathogens.
Soft rot also known as Choanephora or wet rot is a disease most commonly found on summer squash under wet conditions.
This disease also infects other cucurbits including pumpkins and zucchini. The fungus can infect flowers or fruit during prolonged wet periods.

Carbon dioxide assimilation occurs through the Calvin cycle.
The Calvin cycle reactions fix CO₂ from the environment to build carbohydrate molecules. An enzyme, RuBisCO, catalyzes the fixation reaction, by combining CO₂ with RuBP.
Calvin cycle is a series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into glucose.