Lakhmir Singh Biology Class 10 Solutions Page No:258 Question 1: Name two fossil fuels. Solution : Coal and Petroleum. Question 2: Name the major programme started to replenish forests. Solution : Silviculture Question 3: Apart from the availability of forest products, name two other things which are affected by the destruction of forests. Solution : Quality of soil and sources of water. Question 4: Name

Lakhmir Singh Biology Class 10 Solutions Page No:226 Question 1: What is the functional unit of the environment comprising of the living and non-living components called ? Solution : Ecosystem. Question 2: Name two natural ecosystems and two artificial ecosystems. Solution : Natural ecosystems – Grass land and forest. Artificial ecosystems – Parks and Gardens. Question 3: Which one of the

Lakhmir Singh Biology Class 10 Solutions Page No:191 Question 1: Which of the processes, sexual reproduction or asexual reproduction, brings about maximum variations in the offsprings ? Solution : Sexual Reproduction Question 2: Name one variation in humans connected with ears. Solution : Free Earlobes. Question 3: What constitutes the link between one generation and the next ? Solution : Gametes. Question 4: If the

Lakhmir Singh Biology Class 10 Solutions Page No:141 Question 1: Which life process ensures that a plant or animal species will not disappear from this earth ? Solution : Reproduction. Question 2: What is the name of the reproductive process : (a) which involves two parents ? (b) which involves only one parent ? Solution : (a) Sexual reproduction. (b) Asexual reproduction. Question

Lakhmir Singh Biology Class 10 Solutions Page No:92 Question 1: What is the general name of chemical substances which bring about control and coordination in plants ? Solution : Phytohormones. Question 2: Which plant hormone is responsible for the wilting and falling of leaves ? Solution : Abscisic acid is responsible for the wilting and falling of leaves in

Lakhmir Singh Biology Class 10 Solutions Page No:23 Question 1: Which is the basic requirement of living organisms for obtaining energy ? Solution : Food is the basic requirement of living organisms for obtaining energy. Question 2: Which of the following type of energy is used by living organisms to perform vital life processes ? Kinetic energy, Chemical energy,

Lakhmir Singh Chemistry Class 10 Solutions Page No:281 Question 1: (a) On what basis did Mendeleev arrange the elements in his periodic table ? (B) On what basis are they arranged now ? Solution : (a) Mendeleev arrange the element in his periodic table on the basis of atomic masses. (b) Now they are arranged on the

Lakhmir Singh Chemistry Class 10 Solutions Page No:220 Question 1: Name the element whose one of the allotropic forms is buckminsterfullerene. Solution : Carbon Question 2: What are the two properties of carbon which lead to the formation of a large number of carbon compounds ? Solution : Catenation(Self linking of carbon atoms to form long chains) and Tetravalency. Question

Lakhmir Singh Chemistry Class 10 Solutions Page No:131 Question 1: Name one metal and one non-metal which exist in liquid state at room temperature. Solution : Metal – Mercury. Non metal – Bromine. Question 2: Why are metals called electropositive elements whereas non-metals are called electronegative elements ? Solution : Metals are electropositive elements because they can form positive

Lakhmir Singh Chemistry Class 10 Solutions Page No:66 Question 1: What colour do the following indicators turn when added to a base or alkali (such as sodium hydroxide) ? (a) methyl orange (b) litmus (c) red cabbage extract Solution : (a) Yellow. (b) Blue. (c) Green. Question 2: What colours do the following indicators turn when added to an acid (such as