CLASS X BIOLOGY

Origin of Life: Evolution can explain formation of many species ultimately from a single  species in the past. But origin of life (first species) needs further explanation. Oparin and Haldane proposed biochemical theory of evolution : Chemical evolution : Formation of simple organic substances (amino acids,  glucose, nucleotides) from inorganic substances CH4, NH3, H2S on primitive Earth. Biological/ Organic Evolution : Formation of first primitive cell using organic  molecules. Evolution of different forms of life forms from simple unicellular  prokaryotic organism Miller and Urey experiment : They simulated primitive earth. Primitive reducing atmosphere             Gases like H2S, NH3, CH4 Evaporation from hot oceans                Boiling water in flask Lightening                                             Electrodes Rainfall                                                 Condensation using cold water They showed formation of simple substances in wa

Class XA, XB , XC : Prepare a report on the following topics: i) Global warming     (Roll no 1-5) ii) Ozone depletion    (Roll no 6-10) iii) Rain water harvesting   (Roll no 11-15) iv) Biological magnification  (Roll No 16-20) v) The magic 3- Reduce, Recycle and Reuse   (Roll no 21-25) vi) Organic farming  (Roll no 26-30) vii) Carbon footprints- how to reduce them (Roll no 31-35) viii)Vanmahotsava (Plants that can be grown in kitchen garden/community parks.)(Roll no 36-40) ix) Disappearance of House sparrow (Roll no 41-46)