Science & Technology General Knowledge Questions


Which of the following diseases is commonly found in areas where Maize is main diet?

Pellegra is commonly found in areas where Maize is main diet because it leads to vitamin B3 (Niacin) deficiency. The vitamin B3 is found in maize diet but this is in a form that cannot be absorbed.


The plants which flower only once in their lifetime are called?

Plants that flowers once in their lifetime are called MONOCARPIC plants.


Pollination by which of the following will be called Entomophily?
[D]House Sparrow

Pollination by insects is called entomophily. Entomophily is a form of plant pollination whereby pollen is distributed by insects, particularly bees, Lepidoptera (e.g. Butterflies and moths), flies and beetles.


Which of the following refers to Secondary growth in plants?
[A]Development of secondary organs after the plant attains maturity
[B]Development of flowers and fruits
[C]Growth in length and development of new branches after the plant starts flowering
[D]Formation of secondary tissues by the activity of lateral meristems

Formation of secondary tissues by the activity of lateral meristems
Growth in vascular plants resulting from the production of layers of secondary tissue by a lateral meristem (the cork cambium or the vascular cambium). The new tissue accumulates and results in thicker branches and stems. Secondary growth occurs in gymnosperms, most eudicots, and woody magnoliids (such as the magnolia). Most monocots and herbaceous plants undergo little or no secondary growth but simply stop growing when their primary tissues mature.


Which of the following scientists of India is related to theory of Black hole?
[A] C.V. Raman
[B] H.J. Bhabha
[C] S. Chandrashekhar
[D] H. Khurana

S. Chandrashekhar
In 1931, the astrophysicist Subrahmanyan Chandrasekhar theorised that a star would not form a stable white dwarf at the end of its life if its mass was greater than 1.44 times the solar mass (1.44 Ms). This is known as the Chandrasekhar limit, above which the white dwarf will explode as what is called a “Type 1a supernova”. This work fetched Chandrasekhar the Nobel Prize in 1983. His work led to current theory of Black Hole. A black hole is a region of space time from which gravity prevents anything, including light, from escaping. The hole is called “black” because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics In 1931, Subrahmanyan Chandrasekhar calculated, using special relativity, that a non-rotating body of electron-degenerate matter above a certain limiting mass (now called the Chandrasekhar limit at 1.4 solar masses) has no stable solutions.


In human body, “Thrombin” plays important role in which of the following physiological processes?
[A] Excretion
[B] Blood clotting
[C] Reproduction
[D] Growth

Blood clotting
Thrombin is a serine protease that in humans is encoded by the F2 gene. In the blood coagulation pathway, thrombin acts to convert factor XI to XIa, VIII to VIIIa, V to Va, and fibrinogen to fibrin.


Which of the following is the insectivorous fish used for mosquito control?
[A] Hilsa
[B] Labeo
[C] Gambusia
[D] Mystus

Gambusia is a large genus of fish in family Poeciliidae. Gambusia species are also known as mosquito fish, which, refers more specifically to two species, G. Affinis and G. Holbrooki. These can be introduced into ponds to eat mosquito larvae. That’s why, Insectivorous fish used for mosquito control is Gambusia.


In which cropping pattern, the crops are grown in the inter spaces between rows of planted trees?
[A] Relay cropping
[B] Mixed cropping
[C] Inter-cropping
[D] Alley cropping

Alley cropping
A cropping system where crops are grown in the inter spaces between rows of planted trees is called Alley cropping. It is a simple technique that restores nitrogen to the top layer of soil so that farmers can use the same piece of land year after year to grow their crops.


NASA’s Low-Density Supersonic Decelerator project aims to test technique for atmospheric entry on which planet?

The Low-Density Supersonic Decelerator or LDSD is a re-entry vehicle designed to test techniques for atmospheric entry on Mars. The disc-shaped LDSD uses an inflatable structure called the Supersonic Inflatable Aerodynamic Decelerator (SIAD), which is essentially an donut-shaped balloon, to create atmospheric drag in order to decelerate the vehicle before deploying a large supersonic parachute. The goal of the project is to develop a re-entry system capable of landing 2- to 3-ton payloads on Mars, as opposed to the 1-ton limit of the currently used systems.


Which is the most common chemical used in cloud seeding?
[A]Potassium bromide
[B]Silver iodide
[C]Potassium chloride
[D]Magnesium iodide

Silver iodide
The most common chemicals used for cloud seeding include silver iodide, potassium iodide and dry ice (solid carbon dioxide). Cloud seeding process involved a furnace in which coal is burnt at 1,350 degrees Celsius in which powdered Silver Iodide is sprinkled. These particles rise in the air to cloud level in 10-12 minutes. After these particles travel upwards, they crystallize at minus-five degrees and since clouds have both ice and water crystals, the particles attract the water, its weight increases and they fall down in the form of rain within a couple of hours.