air zone cross bow

. This zone is called troposphere. Therefore, at higher altitudes, some of us find it difficult to breathe. Above the troposphere is the stratosphere. This zone is rich in ozone. Hence, it is also called ozonosphere. In ozonosphere, the sunlight converts oxygen to ozone by photo..

The biological rhythms synchronised with the low and high tides in the sea are called as circatidal rhythms. Thus the organisms living in the inter tidal zone are alternatively submerged and exposed to air. The other rhythms are circa lunar rhythms, semi lunar rhythm and circann..

It is the movement of water between aquatic systems, air and land water vapour condenses to form clouds, and eventually rainfall. Plants play an important role in this cycle by the process of transpiration. The upper limit (maximum) of water availability of a soil is called field capac..

Vibration of Stretched Strings - In physics, the word 'string' is used in a more general sense than what it normally denotes. In olden days, musical instruments employed strings of twisted intestines of animals, such as cat-gut. Nowadays, the strings of musical instruments like the veena, violin an..

A thick gaseous envelope surrounding the earth is called atmosphere. The density of air in the atmosphere varies with altitude. Atmosphere is divided into five different layers or zones: Troposphere Stratosphere Mesosphere Ionosphere Exosphe..

Bundles of muscle fibres are grouped in a fascicule, which are held together and enclosed by collagen fibres and by connective tissue. A tough outer layer called fascia, lying below the skin, surrounds the bundles of fascilli. A highly magnified view of skeletal muscle fibre reveals thread-like st..

Construction of sound proof rooms for noisy machines in industries. Use of horns with jarring sounds to be banned. Noise producing industries, aerodromes, and railway stations to be shifted away from the inhabited areas. Proper law should be enforced to check the misuse of loudspeakers a..

The electromagnetic spectrum of solar radiation Animals depend on light for orientation, diurnal migration and synchrony of rhythmic activities. Hence receptors for light are common to all animals, in those with better developed photoreceptors, light greatly influences behavior. Light energy varies..

; complete bending down takes place, as illustrated in the below figur..

Gaseous Exchange in Grasshopper - The respiratory system in insects is called the tracheal system. It involves the diffusion of oxygen directly from the atmosphere into the air-filled tubes. Thus, the diffusion is through air and hence, is more efficient than the diffusion throu..