Science & Mathematics Questions & Answers

‘The Flowers of Painted Lady’ plants contain an insecticidal element, pysellethein, which is the main ingredient used in mosquito repellent coils and mats. Just about 2 to 4 microorgams of this element is enough to kill a mosquito. Lesser doses of this paralyses them. However, pysellethein does not affect the warm-blooded species. An average mat or coil contains only 40 …

Certain rocks give off high energy radiation due to the presence of radioactive substances in them. Radioactive substances have got the property of decay (break down of active material with the passage of time). For example, uranium decays giving rise to lead. By measuring the amount of lead-present in the uranium sample scientists can determine the ages of rocks by …

The solid state of matter in which the atoms or molecules are arranged in a definite repetitive geometric patterns is known as crystal. Liquid metals, alloys, minerals and some organic materials solidify into crystalline form. A slower rate of cooling results in a larger crystal. Crystals have flat boundary planes or faces. A diamond is an allotrope (another form) of …

An anti-particle is a sub-atomic particle that has the same mass as another particle and equal but opposite values of some other property or properties. For example, positron is the anti-particle of electron having a positive charge. Similarly, anti-proton has the negative charge. Anti-matter is postulated to consist of matter made up of anti-particles. For example, anti-hydrogen would consist of …

In winters our body has to work more actively to adjust to the difference between the body temperature and the atmospheric temperature. It is because of this that the sensation of pain appears more in winter than in summers. Funny Logic The flow of blood under the skin is sluggish during winters due to the contracting of surface blood vessels. …

Birds are warm blooded creatures, whereas reptiles are not. It means that birds, like human beings, have an automatic system of keeping the temperature of the body warm, controlled in hypothalamus in the brain. Reptiles on the other hand, including fish, amphibians and invertebrates are poikilothermic-their body temperature fluctuates with the temperature of the surroundings. As such the poikilothermic creatures do not …

Lizards are poikilothermal (cold-blooded) and their body temperature fluctuates with outside temperature. When it’s extremely cold, lizards face the danger of either their blood freezing up or their temperature dropping drastically, as a result of which they become immobile and can easily fall prey to enemies. Hence, lizards hibernate in cracks of walls or beneath the soil. During this period, …

The wings of butterflies are covered with small scales. These tiny scales produce magnificent colours and pattern by optical interference of light. The tiny scales reflect and disperse light producing the brilliant colours. When we touch the wings of a butterfly these tiny scales come out in the form of powder, thereby leaving the surface of the wings colour less. …

Radiation emitted by light sources are responsible for attracting insects towards it. A series of experiments have confirmed that a narrow band of infra-red radiation emitted by light sources attract insects. A study was conducted on moths. It was observed that, only the males of the species got attracted towards the light source, mistaking it for female moths. Female moths …

All snakes have poison glands, but the presence of fangs for injecting venom and the type determines whether a snake is poisonous or not. Fangs are normally present in the upper jaw. Snakes with tubular fangs, small scales on the head and wide belly-scales running across its width are poisonous. Snakes with solid fangs or without fangs, and short scales …