Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

Formation of embryo sac is Megagametogenesis.
Megagametogenesis is the process of maturation of the female gametophyte, or megagametophyte, in plants.
During the process of megagametogenesis, the megaspore, which arises from megasporogenesis, develops into the embryo sac, which is where the female gamete is housed.
These megaspores then develop into the haploid female gametophytes. This occurs within the ovule, which is housed inside the ovary.

The perfect stage of Blast of rice is Magnaporthe.
The fungus that causes rice blasts is called Magnaporthe oryzae (formerly Magnaporthe grisea).
It is an ascomycete because it produces sexual spores (ascospores) in structures called asci, and is classified in the newly erected family Magnaporthaceae.

Sodium is not an essential element for plants among the given options whereas all the other elements like Iron, Potassium, and Zinc are under 17 essential elements required for proper growth and development of plants.
Sodium is not an essential element for plants but can be used in small quantities, similar to micronutrients, to aid in metabolism and synthesis of chlorophyll.

Glycolate accumulates in chloroplasts when there is Low CO₂.
glycolate is produced during photosynthesis as a result of a reaction between a 2-carbon piece derived from a sugar phosphate and an oxidant generated by the photochemical act.
Glycolate leads to the inhibition of metabolic processes that impair CO₂ assimilation. Furthermore, glycolate feeding to Arabidopsis roots strongly reduces root growth indicating toxic effects not related to photosynthetic processes.

Uniformly sweet taste of Tea or Coffee is due to Diffusion.
Diffusion is the net movement of anything generally from a region of higher concentration to a region of lower concentration.
The central idea of diffusion, however, is common to all of these: a substance or collection undergoing diffusion spreads out from a point or location at which there is a higher concentration of that substance or collection.

Penicillin antibiotic was first time demonstrated by Fleming (1929).
Scottish physician Alexander Fleming was the first to experimentally discover that a Penicillium mould secretes an antibacterial substance and the first to concentrate the active substance involved, which he named penicillin.
He concluded that the mould was releasing a substance that was inhibiting bacterial growth, and he produced culture broth of the mould and subsequently concentrated the antibacterial component. After testing against different bacteria, he found that the mould could kill only specific bacteria.

Rickettsia can be diagnosed by Giemsa stain.
The rickettsiae are a diverse collection of obligately intracellular Gram-negative bacteria found in ticks, lice, fleas, mites, chiggers, and mammals. They include the genera Rickettsiae, Ehrlichia, Orientia and Coxiella.
Giemsa stain named after German chemist and bacteriologist Gustav Giemsa is a nucleic acid stain used in cytogenetics and for the histopathological diagnosis of malaria and other parasites.
Giemsa stain is used in Giemsa banding, commonly called G-banding, to stain chromosomes and is often used to create a karyogram (chromosome map). It can identify chromosomal aberrations such as translocations and rearrangements.

Covered smut of barley (Caused by Ustilago hordei) is Externally seed borne.
Covered smut of barley is caused by the fungus Ustilago hordei. The disease is found worldwide and it is more extensively distributed than either loose smut or false loose smut.
Kernels of infected plants are replaced by masses of dark brown smut spores. Smutted heads are hard and compact. Infected plants may be stunted.
Infection is seed-borne within the seed, the fungus penetrating the endosperm while the grain is being formed. Infected seeds give rise to systemically infected plants. The mycelium advances through the host tissue and becomes established behind the growing point.

Albugo candida produces Oospores.
Albugo candida, commonly known as white rust, is a species of oomycete in the family Albuginaceae. A. candida is an obligate plant pathogen that infects Brassicaceae species and causes the disease known as white rust or white blister rust.
Thick-walled sexual spores, called oospores are produced which germinate, producing either vesicle inside the plant tissue, exit tubes with vesicles at the tip, or germ tubes. Further zoospores develop inside the vesicles. The infection is spread by either oospore-infected seed or by mechanical movement of sporangia.

Kassanis discovered satellite virus.
Satellite tobacco necrosis virus (STNV) was the first satellite virus to be recognized, the term “satellite virus” being coined to denote the 18 nm isometric particles associated with the 28 nm TNV isometric particles by Kassanis, in 1962.
Satellite viruses (SVs) are subviral pathogens that are entirely dependent upon the replication machinery of their helper viruses. There are only four known plant SVs, satellite tobacco necrosis virus, satellite tobacco mosaic virus, satellite panicum mosaic virus, and satellite maize white line mosaic virus.