RRB Group D GK Questions 2026

Blood is classed as a connective tissue because its cells lie in a matrix, and because that matrix, the plasma, is liquid it is called a fluid connective tissue; the red cells, white cells and platelets float in it and it connects the organs of the body by carrying gases…

The muscle of the heart shows light and dark bands under the microscope, so it is striated, yet it is not under the control of the will and it contracts rhythmically without rest for the whole of life, so it is involuntary; this unusual combination is exactly why it is…

A neuron carries a long process called an axon, which in a human being may run from the base of the spine to the toe, so a single nerve cell can be about a metre long; this length lets one cell carry an impulse over a great distance without any…

Xylem is a complex permanent tissue of tracheids, vessels, xylem parenchyma and xylem fibres; the vessels and tracheids are dead, hollow and joined end to end, which makes them ideal pipes for carrying water and minerals from the root to the leaves in one direction.

A tendon is made of dense white fibrous connective tissue with great tensile strength and almost no elasticity, so when a muscle contracts the whole pull is transmitted to the bone without being lost in stretching.

Matthias Schleiden, a botanist, concluded that all plants are made of cells, and Theodor Schwann, a zoologist, reached the same conclusion for animals; together their statement became the cell theory.

A lysosome is a membrane-bound sac of powerful digestive enzymes that breaks down worn-out organelles and any foreign particle the cell takes in; if the cell is damaged or starving, the sacs burst and the same enzymes digest the cell itself, which is why the name suicide bag is used.

Both carry a small circular DNA of their own and their own 70S ribosomes, so they make a part of their protein themselves and divide independently of the cell; this semi-autonomous nature is the main evidence for the view that they descend from free-living bacteria engulfed by an early cell.

In 1665 he cut a thin slice of cork, examined it under a microscope of his own making and saw rows of empty boxes, which he named cells after the small rooms of a monastery; the drawing and description appeared in his book Micrographia.

It was founded in 1929 as the Imperial Council of Agricultural Research on the recommendation of the Royal Commission on Agriculture, has its headquarters at New Delhi and coordinates research, education and extension through a national network of institutes and agricultural universities.

Plantation agriculture is a type of commercial farming in which one crop such as tea, coffee, rubber, sugarcane or banana is grown over a large area with hired labour, capital investment and a processing unit on or near the estate.

Pulses are leguminous plants whose roots carry nodules containing Rhizobium bacteria. These bacteria convert nitrogen from the air into compounds the plant can use, and part of that nitrogen stays in the soil after harvest, so the cereal that follows needs less fertiliser.

Operation Flood was the dairy development programme of the National Dairy Development Board that linked village milk producers' cooperatives to city markets and made India the largest milk producer in the world.

Jute is called the golden fibre because of its shining golden brown colour and the high export value it once commanded.

Podu is the local name for slash and burn or shifting cultivation in Andhra Pradesh, where a patch of forest is cleared, burnt and cropped for a few years and then left to recover while the cultivator moves to a fresh patch.

Black soil, also called regur or black cotton soil, covers much of the Deccan plateau and is formed from the weathering of lava.

The pink bollworm is the most damaging pest of the cotton plant.

In the colour coding of India's agricultural revolutions the Silver Fibre Revolution stands for cotton, the fibre crop of the black soil regions of Gujarat, Maharashtra and Telangana.

Both are sown in October and November after the monsoon withdraws and harvested in March and April. Barley is a coarse cereal grown mainly in Rajasthan and Uttar Pradesh, and gram is the most important rabi pulse of India, grown in Madhya Pradesh, Rajasthan and Maharashtra.

Wheat is the leading rabi crop of India. It is sown in October and November, needs a cool season of about fifty to sixty centimetres of rainfall for growth and bright sunshine at the time of ripening, and is harvested in March and April.