Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

Magnesium is a part of Chlorophyll.
The presence of magnesium in chlorophyll was discovered in 1906, and was that element's first detection in living tissue.
The chlorophyll molecule consists of a central magnesium atom surrounded by a nitrogen-containing structure called a porphyrin ring; attached to the ring is a long carbon-hydrogen side chain, known as a phytol chain.

Direction of conduction of food through phloem is from leaves to roots.
Phloem is the vascular tissue that transports food (photosynthates) from the leaves to basal parts of the plant, and vascular cambium is undifferentiated tissue responsible for secondary growth and repair of damaged phloem.
The main role of the phloem tissue is to transport carbohydrates from sources to sinks through the sieve elements, phloem is also composed of parenchyma cells, which play a key role in the storage of water, non-structural carbohydrates and storage proteins.

Tea rust is caused by Algae.
'Red rust' caused by Cephaleuros parasiticus Karst is the most important and lone algal disease of tea.
The regular incidence of this disease and its effect on the growth and vigour as well as the yield potential of tea called for investigation into the phenology and appropriate remedy of this disease.

When half the leaves are removed randomly, transpiration will show lower magnitude but higher flux.
Less number of leaves offers less opportunity for transpiration, therefore the rate of transpiration will be lower on magnitude but flux is higher.
Transpiration (T) is the flux of water vapour and latent energy returned to the atmosphere by vascular plants, mainly through the stomatal pores on their foliage and concurrent with photosynthesis.

Sperm and egg nuclei fuse due to attraction of their protoplasts.
The two gametes i.e., sperm released by pollen tube and egg move in opposite direction by an unknown mechanism but most probably by streaming currents of cytoplasm i.e., due to attraction of their protoplasts.
The nucleus of one male gamete fuses with the egg nucleus and the phenomenon is called fertilization.

In 2005, S. Nagarajan, pathological scientist got Borlaug award.
The Borlaug Award is an award recognition conferred by a fertilizer company, Coromandel International, for outstanding Indian scientists for their research and contributions in the field of agriculture and environment.
Nagarajan, who is internationally respected as a wheat pathologist, has been recognized with the Borlaug award of the Coromandel Fertilizers (2004 - 2005) for his contribution to the advancement of the wheat program, pathology of wheat rusts and its elimination, and as an educator.

A major use of embryo culture is in overcoming hybridization barriers.
Embryo culture is a technique for cultivating an embryo under aseptic conditions on a nutrient medium.
It is performed with mature embryos and helps mainly in shortening the period of germination by overcoming seed dormancy and any barriers to overcoming hybridization.

Amino acids are mostly synthesized from α-ketoglutaric acid.
α-Ketoglutarate is one of the most important nitrogen transporters in metabolic pathways. The amino groups of amino acids are attached to it (by transamination) and carried to the liver where the urea cycle takes place.
α-Ketoglutarate is transaminated, along with glutamine, to form the excitatory neurotransmitter glutamate. Glutamate can then be decarboxylated into the inhibitory neurotransmitter gamma-aminobutyric acid.

The chemical structure of chlorophyll a varies from chlorophyll b due to difference between CH₃ and CHO.
Chlorophyll a is a specific form of chlorophyll used in oxygenic photosynthesis. Chlorophyll b helps in photosynthesis by absorbing light energy.
In chlorophyll a, third carbon of the side group is -CH₃. In chlorophyll b, side group at the third carbon is -CHO. It is more soluble than chlorophyll a in polar solvents because of its carbonyl group.

The disease caused by Leptosphaeria sacchari in sugarcane is Ring spot.
Leptosphaeria sacchari is a plant pathogenic fungus that causes a disease called ring spot on Saccharum officinarum.
The infection occurs on the leaves of lower canopy of the crop and starts as small bronze spots. The spots elongate to become longer, irregular-shaped lesions (2.5 to 5 mm × 10 to 18 mm) with red-brown borders.