RRB Group D GK Questions 2026

Guard cells are specialised epidermal cells that surround each stoma on the surface of a leaf. Each stoma is a tiny pore bordered by two guard cells, which are bean-shaped in most plants and dumb-bell shaped in grasses.

Platelets plug a damaged vessel and start the chain that forms a clot. Platelets, or thrombocytes, are small cell fragments made from large cells called megakaryocytes in the bone marrow.

The correct answer is A, Mirzapur and Sonbhadra, the Vindhyan districts of the south-east, where dry deciduous forest grows on hilly ground and the tendu tree is common; its leaves are collected and dried to roll bidis and give seasonal work to thousands of forest dwellers, along with khair for…

Heavy rainfall and a high water table there support tropical moist deciduous forest in which sal, Shorea robusta, is the chief tree, in Lakhimpur Kheri, Bahraich, Pilibhit, Shravasti, Balrampur and Gorakhpur, and Dudhwa National Park and the Pilibhit Tiger Reserve lie inside this belt.

Formed on the Vindhyan and Deccan trap rocks of the south, it is clayey, dark and able to hold water through a dry spell, which is why the gram, wheat, oilseed and pulse crops of Jhansi, Jalaun, Hamirpur and Banda depend on it.

Bhur is the raised sandy soil of the upper doab in districts such as Meerut, Bulandshahr and Aligarh, blown into low ridges by the wind, poor in moisture and organic matter, and fit for bajra, barley and, where irrigation reaches, for sugarcane.

Usar, also called reh, is the saline and alkaline soil of districts such as Raebareli, Unnao, Hardoi, Kanpur and Aligarh, where sodium salts gather on the surface; gypsum, which is calcium sulphate, replaces the sodium on the clay particles with calcium, the sodium is then washed away by drainage, and…

Bhangar is the old alluvium of the higher ground away from the present river channels; it is darker, more clayey and dotted with the lime concretions called kankar, and it is not renewed by fresh silt.

Western disturbances travel from the Mediterranean across Iran and Pakistan and give the plains a few spells of light rain in December, January and February, exactly when wheat, gram, barley and mustard are standing in the field, so farmers call this shower the golden drops.

It is a hot, dry and dusty wind that blows from the west over the northern plains in the afternoons of May and early June, pushing the temperature past forty-five degrees Celsius in Agra, Jhansi and Banda and causing heat stroke, and it stops only when the monsoon arrives.

The monsoon current enters from the Bay of Bengal in the south-east and loses moisture as it travels up the plain, so the eastern districts and the Terai of Gorakhpur, Bahraich and Lakhimpur Kheri are the wettest, while Mathura, Agra and the Bundelkhand districts of Jhansi, Jalaun and Banda are…

This branch strikes the Ganga delta, is turned west by the Himalaya and moves up the Ganga plain, so it reaches eastern Uttar Pradesh about the middle of June and then travels on to the west, which is why the east of the state gets both earlier and heavier rain.

Keoladeo Ghana National Park at Bharatpur, once the duck shooting reserve of the Bharatpur rulers, was listed in 1981 and is also a World Heritage Site famous for its winter migratory birds; the Sambhar salt lake was listed in 1990 and attracts flamingos.

Nakki lake lies at Mount Abu, the only hill station of Rajasthan, in Sirohi district, and the local story that it was dug out with nails gives it its name; Toad Rock stands on its edge and the ashes of Mahatma Gandhi were immersed in it.

The correct answer is A, Maharana Jai Singh of Mewar, who dammed the Gomti river in the late seventeenth century to make the lake in Udaipur district; it is the largest artificial freshwater lake of Rajasthan and is surrounded by the Jaisamand wildlife sanctuary, with marble pavilions and the Hawa…

The lake spreads over the districts of Jaipur, Nagaur and Ajmer, is fed by the Mendha, Rupangarh, Khari and Khandel streams, has been worked for salt for centuries and was declared a Ramsar site in 1990, drawing flamingos in winter.

The Mahi enters Rajasthan from Madhya Pradesh in Banswara district, where it is dammed as the Mahi Bajaj Sagar, a joint project of Rajasthan and Gujarat; the river is called the Ganga of Vagad and receives the Som, the Jakham and the Anas.

The Bisalpur dam stands on the Banas in Tonk district and supplies drinking water to Jaipur, Ajmer, Tonk and the towns between them, which makes it the most important water project of eastern Rajasthan.

It rises in the Shivalik hills near Kalka, enters Rajasthan at Talwara in Hanumangarh district and loses itself in the sands near Suratgarh and Anupgarh, so it never reaches the sea and is called the dead river; its dry bed is known locally as the Nali, and Harappan sites such…

The Luni begins in the Naga hills near Ajmer and is called the Sagarmati in its first stretch; after the Sarsuti joins it near Govindgarh the combined stream is called the Luni, and it finally spreads into the Rann of Kutch in Gujarat.