Biology Blogs For Class11th, 12th and NEET

                                          X-Ray and DSA   Introduction - It is one of the oldest methods of imaging which starts with the accidental discovery of X-ray by Wilhelm Knored Roentgen , a German physicist in 1895.  The branch of science that deals with the study of X-ray for the detection and treatment of diseases are called Radiology. Principle - High dose X-ray is passed through the body where the body absorbs this radiation and scatter this radiation to all over the body and the remaining x-ray pattern is recorded for later evolution. Uses -  X-ray imaging is usually applied in detecting bone fractures and dislocations.            This technique is also advantageous in detecting the disease of  the heart and lungs .            In Dental Examination.             In Mammography Digital Subtraction Angiography (DSA) - DSA is an imaging technique that produces clear views of flowing blood in vessels and indicates the presence of blockages, If any. A

                                       Phylum - Chordata               Class Amphibia  As the name indicates (Gr., Amphi : dual, bios, life), amphibians can live in aquatic as well as terrestrial habitats. Most of them have two pairs of limbs. Body is divisible into head and trunk. Tail may be present in some. The amphibian skin is moist (without scales). The eyes have eyelids.  A tympanum represents the ear. Alimentary canal, urinary and reproductive tracts open into a common chamber called cloaca hich opens to the exterior. Respiration is by gills, lungs and through skin. The heart is threechambered (two auricles and one ventricle). These are cold-blooded animals. Sexes are separate. Fertilisation is external. They are oviparous and development is indirect. Earliest amphibians - Ichthyostega basically a fish with legs          numerous digits on hands, feet tail fin with fibrous rays like a fish one of the best transitional series in the fossil reco