Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

Tobacco root exudates contain Acetosyringone chemical substances during induction of chemotaxis against A. tumefaciens.
Agrobacterium tumefaciens is a soil phytopathogen that naturally infects plant wound sites and causes crown gall disease via delivery of transferred (T)-DNA from bacterial cells into host plant cells through a bacterial type IV secretion system.
Acetosyringone is known to improve transformation efficiency by up-regulating the virulence of Agrobacterium. In previous studies using Eustoma, the effect of this compound has only been tested during inoculation.

The leaves of Pongamia glabra and Azadirachta indica reduce the population of Root-knot nematode.
Root-knot nematode larvae infect plant roots, causing the development of root-knot galls that drain the plant's photosynthetic and nutrients. Infection of young plants may be lethal, while infection of mature plants causes decreased yield.
To kill nematodes in soil, heat small quantities of moist soil to 140°F in the oven or by solarization. The leaves of the above specific trees also reduce the population of nematodes.

Photosynthetic pigments found in the chloroplasts occur in Thylakoid membranes.
Thylakoids are membrane-bound compartments inside chloroplasts and cyanobacteria. They are the site of the light-dependent reactions of photosynthesis. Thylakoids consist of a thylakoid membrane surrounding a thylakoid lumen.
The thylakoid membrane is the site of the light-dependent reactions of photosynthesis with the photosynthetic pigments embedded directly in the membrane. It is an alternating pattern of dark and light bands measuring each 1 nanometre.

The secondary nucleus is diploid.
The secondary (definitive) nucleus is formed by the fusion of two haploid polar nuclei hence it is diploid (2n).
It is also called the primitive endosperm nucleus. It is the main food source for angiosperm embryos.

White blisters of crucifers' is caused by the pathogen Albugo candida.
A. candida is an obligate plant pathogen that infects Brassicaceae species and causes the disease known as white rust or white blister rust. It has a relatively smaller genome than other oomycetes.
White rust, also called white blisters, is a fungal disease caused by the fungus Albugo candida, which affects cruciferous plants that include vegetables such as kale, Brussels sprouts, cauliflower, broccoli and cabbage.

Scab is a result of Hyperplasia.
Sebaceous hyperplasia is a skin condition that becomes more common with age. It's caused when your sebaceous oil glands produce too much oil, which can be trapped under your skin and cause bumps.
This creates shiny bumps on the skin, especially on the face. Scab is a mass of dried blood that forms over a part of the body where the skin has been cut or broken, it is sometimes caused as a result of hyperplasia.

The term virus was first time coined by Beijerinck.
Beijerinck, in 1898, was the first to call 'virus', the incitant of the tobacco mosaic.
Martinus Willem Beijerinck was a Dutch microbiologist and botanist who was one of the founders of virology and environmental microbiology.
He showed that the inoculant was able to migrate in an agar gel, therefore being an infectious soluble agent, or a 'contagium vivum fluidum' and definitively not a 'contagium fixum' as would be a bacteria.

When daylight hours are increased, the rate of photosynthesis remains unchanged.
"When a process is conditioned as to its rapidity by several separate factors the rate of the process is limited by the pace of the slowest factor." Limiting factors are not limited to the condition of the species.
When during the day, light hours are increased, it does not affect the rate of photosynthesis much, therefore, the rate of photosynthesis remains unchanged.

Race II of Ralstonia solanacearum cause disease in potato.
Ralstonia solanacearum is a soil-borne bacterium causing the widespread disease known as bacterial wilt. Ralstonia solanacearum is also the causal agent of Moko disease of bananas and brown rot of potato.

Thylakoids possess photosynthetic units called Quantasomes.
Quantasomes are particles found in the thylakoid membrane of chloroplasts in which photosynthesis takes place. They are embedded in a paracrystalline array on the surface of thylakoid discs in chloroplasts. They are composed of lipids and proteins that include various photosynthetic pigments and redox carriers.
Quantasomes were first identified by Roderic B. Park in 1962. Each quantasome contains about 230 - 250 chlorophyll molecules and 50 molecules of carotenoids.