Agriculture - 1 (B.Sc. Agriculture)

'Khaira' disease of rice is caused due to zinc deficiency.

In sugarcane production, seeds are not used, instead vegetative cuttings of sugarcane are used.

In this step, carbon dioxide enters and is reduced to form starch.

 The botanical name of the cotton-yielding plant is Gossypium hirsutum.

Maize is a c4 plant.

Chromosome number is fixed for a species.
The lowest number is seen in Haplopapas gracilis (Asteracease), i.e. 2n = 4 and maximum in some Ophiglosum species (pteridophyte), i.e. 2n = 1656. 

Soybean is indeed one of the richest plant sources of protein, containing about 36-40% protein by weight. It's a complete protein source with all essential amino acids, making it valuable for vegetarian diets.

Cotton fibers are almost pure cellulose (about 90-94%), making it the world's most important natural fiber for textiles. The cellulose gives cotton its strength, absorbency, and comfort properties.

 Apple scab is caused by Venturia inequalis.The disease manifests as dull black or grey-brown lesions on the surface of tree leaves, buds or fruits.

If freshly harvested grains (seeds) are stored without drying, they may get spoilt or attacked by organisms, losing their germination capacity.
Hence, before storing them, grains are properly dried in the sun to reduce moisture in them.
This prevents the attack by pests, bacteria and fungi.

Sprinkler system is a modern method of irrigation.

Cash crops are grown primarily for sale rather than subsistence. Cotton, groundnut, and jute are important cash crops. Jowar is a food crop (cereal) primarily grown for human consumption, making it the correct answer.

The correct matching is: Rice (A) - Gundhi bug (2), Wheat (B) - Aphid (1), Sugarcane (C) - Top shoot borer moth (4), Gram (D) - Greasy cutworm (3). This matches option C.

A mature fruit is botanically defined as a ripened ovary. After fertilization, the ovary wall develops into the fruit wall (pericarp) that protects the seeds. This is why all fruits contain seeds.