Pictures of various organisms are given in figure 7.2 on page no. 82 of your textbook. Construct a food web from those pictures.

Study the various compoents given in figure 7.5 on pages no . 84 your textbook and explain the bio-geo -chemical cycle in your own words.

Observe figure 7.1 given on page no. 81 of your textbook and explain the relationship between the given components.

To charge an object by induction. : Rub a comb or a balloon on your hair. As shown in the picture 8.4 on page 54 of your textbook, take the comb near a thin trickle of water from a tap what happes. Now draw the comb away from the trcikle and observe what happens. : Mark your observation with a tick. : When the charged comb is brought close to the flowing water, water gets attracted/repelled/remains as it was. : when the charged comb is taken away from the flowing water, it gets attracted.repelled/remains as it was initially.

Assign names in the figure given on textbook page no. 88. Explain the various stages those are kept blank.

Discuss about stem cells and organ transplantation in · the class with the help of figures given on page no. 90 of your textbook.

Complete the paragraph by choosing the approprite words given in the brackets: Complete the papragraph using proper words: (mechanical, Rhizobium, aquatic, Toxic, co_2 Nitrogen, Pseudomonas, Amoeba, bacteria, hydrocarbons) Spilling of petroleum oil occurs in ocean due to various reasons. This oil may prove fatal and toxic to organisms. It is not easy to remove the oil layer from surface of water by ............. method. However, bacteria like ................ spp. and Alcanovorax borkumensis have the ability to destroy the pyridines and other chemicals. Hence. these ................ are used to clear the oil spills. These are called hydrocarbonoclastic bacteria (HCB). HCB decompose the ....--.----- and bring about the reaction of carbon with oxygen. ...--------- and water is formed in this process.

Light of intensity 10^ −5 W/m 2 falls on a sodium photo-cell of surface area 2 cm^ 2 . Assuming that the top 5 layers of sodium absorb the incident energy, estimate time required for photoelectric emission in the wave-picture of radiation. The work function for the metal is given to be about 2 eV. What is the implication of your answer?

The coutries which do not have oil reservatirs in their land import oil from other countries. But sometimes during transporting oil through sea routes, accidental oil spilling occurs. This oil spilled in the ocean may prove fatal and toxic to aquatic animals. Therefore, removel of this spilled oil is essential for protection of aquatic life. For removing this oil layer, certain microbes like Pseudomonas spp. and Alcanivarax borkumensis are used. These microbes have the ability to destroy the pyridines and other toxic chemicals. The hydrocarbonoclastic bacteria (HCB) are able to decompose the hydrocarbons and bring about the reaction carbon with oxygen resulting in formation of CO_(2) and water. Like oil spills cause damage to aquatic life, platic forms the major part of the grabage on land. Plastics are difficult to degrade as they are made up of PET. By research, various species like Vibrio and Idenoella sakaiensis which can degred PET.By research, various species like Vibrio and Ideonella sakaiensis which can degrade PET have been identified. There are cartain species of microbes which can decompose rubber from garbage. Based on the given paragraph answer the following question. How are aquatic organisms affected by oil spills in oceans ?

Choose the correct alternative from those given below each question: What is the value okf K, if one root of the quadratic equation kx^2-7x+12=0 is 3 ?

Choose the correct alternative from those given below each question: What is the value of D_x for the simultaneous equations 3x+2y+11=0 and 7x-4y=9?