Science & Mathematics Questions & Answers

A blood donor can give about half a litre of blood. The blood is kept for transfusions to help save people’s lives. The body then makes more blood, but the donor should not give blood again for at least two months. Every year on 14 June, countries around the world celebrate World Blood Donor Day.

The cigarette was the last method of taking tobacco to be developed. Previously it had been smoked in pipes and cigars, inhaled as snuff (in powder form) and chewed. Tobacco itself was brought to Europe and the rest of the world when Columbus discovered America, and it was thought to have marvelous medicinal properties. No one could be said to …

The bollygard cotton seed is suspected to have the ‘terminator seed’ technology which involves introduction of a gene that terminates the germination of the seeds after onetime usage. ‘Terminator’ is actually a name coined by the Canadian non-governmental organisation Rural Advancement Foundation International (RAFI) for a technology that essentially controls the expression of certain genes, causing the plant to turn …

What was the test? On March 27, 2019 India conducted Mission Shakti, an anti-satellite missile test, from the Dr. A P J Abdul Kalam Island launch complex. This was a technological mission carried out by DRDO. The satellite used in the mission was one of India’s existing satellites operating in lower orbit. The test was fully successful and achieved all …

There almost 5 liters of blood in the human adult’s body. But it is not the only fluid to circulate. A substance called ‘lymph’ circulates through a network of vessels throughout the body.

Ever since the philosopher and naturalist, Charles Darwin, and his contemporaries including Wallace, suggested that man had evolved from apes, there has been a continuous, and almost frantic quest for evidence of our ancestors. Of course, where we come from has always been a fascinating question, but it is only comparatively recently that systematic searches have been made for traces …

The first folds in the crust of the Earth took place in complete darkness, when the world still felt very hot. The Earth had cooled sufficiently to harden the rocks but its temperature was still far higher than that of boiling water. No water was to be found on the surface and all the water vapour coming from the burning …

A large percentage of the Chinese are followers of Taoism. According to Taoist belief, the Jade Emperor is the ruler of heaven, mankind and hell. It is said that the Jade Emperor decided to assign a different animal for each year, so that people could easily remember the twelve-year zodiac cycle. So he called one representative from each animal species …

हम किसी को फोन करने पर हैलो ही क्यों कहते हैं ? हम चाहे फोन रिसीव करें या कॉल करें। हमारा सबसे पहला शब्द होता है Hello! आखिर हम इसी शब्द का इस्तेमाल क्यों करते हैं? अगर ये कहा जाय कि यह किसी का नाम है तो आप सोंच में पड़ जायेंगे। लेकिन हम आपको बता दें की जी हां, यह नाम था वैज्ञानिक ग्राहम बेल की गर्लफ्रेंड का। जिसका पूरा …

Areas of the brain involved in motor control and reward processing light up more in chronic itch patients when they scratch, according to a new study which may explain why scratching evokes a pleasurable sensation. Researchers in the Department of Dermatology and Temple Itch Center at Temple University School of Medicine (TUSM) used advanced functional magnetic resonance imaging to look …