CBSE Pathshala

Q  Name the cells having branches structure. Ans Nerve Cell. Q Why cells could not be observed before seventeenth century? Ans Cells could not be observed before seventeenth century because till that time microscope was not invented. Q Why plant cell have cell wall? Ans Plant cells need protection against variations in temperature, high wind speed, atmospheric moisture, etc. They are exposed to these variations because they cannot move. That's why they have cell wall. Q Which organism has the smallest cell? Ans  Mycoplasmas, a bacteria has the smallest cell of the size of 0.1 micron i.e. ten thousandth part of a mill metre. ' Q  Which is the largest cell visible by unaided eye? Ans Ostrich egg has the largest visible cell by unaided eye. Q Name the four elements, which fonn major part of protoplasm. Ans These are carbon, hydrogen, oxygen and nitrogen. Q Give two examples of prokaryotes. Ans Bacteria and blue green algae. Q  Name the la...

Book resource: Science power Class 8 th Check point-01 [Formative Assessment]        1. Define Afforestation? Answer:  The practice of planting more and more trees is called Afforestation. 2. What is desertification? What causes desertification? Answer: The phenomenon of converting fertile land into desert is called desertification. Deforestation causes desertification. 3. What is the effect of deforestation on rainfall and climate? Answer:  Deforestation increases temperature and wind velocity that reduce rainfall. These changes led to climate change. Check point-02 [Formative Assessment]        1. What is wild life? Answer: Wild life is an area where organism lives in their natural habitat like dense forest, jungle and water bodies. 2. Give one difference between endangered and vulnerable ? Answer: Endangered are those animals that are not likely survive and will soon extinc...

Class 8th Science Term-01 1. Crops Production and Management 2. Microorganisms-Friend and Foe 3. Force and Pressure 4. Frictions 5. Chemical Effects of Electric Current 6.  Sound, Wave, Music and Noise 7. Synthetic Fibre and Plastics 8. Metals and Non-Metals 9. Conservation   of Plants and Animals Conservation Class VIII Mathematics [Click on links given below] VIII Algebra VIII Commercial Maths VIII Geometry & Mensuration   CBSE Class VIII Science Physics Chemistry Biology 8th Sample paper 8th Social Science

[Practice Paper] LESSON-7 (Combustion and Flame)  LESSON-9(Crop Production and its Management) LESSON-20 (Pollution of water) 2 marks Questions :- Q1 What is a fuel? Give examples Q2 What are combustible materials? Q3 When we boil water in paper cup, the cup does not catch fire. Why? Q4 Define ignition temperature. What is the ignition temperature of White Phosphorus? Q5 What happens when a matchstick is striked against the matchbox? Q6 Flame of a burning candle goes off, when we blow over it strongly. Give suitable reason. Q7 Differentiate between Rapid and Spontaneous Combustion. Q8 Why does a small piece of Sodium or White Phosphorus catch fire in air? Q9 What precautions should be taken at LPG godowns or petrol pumps? Q10 If a person’s cloth catches fire, how can you put it off? Q11 What are the harmful effects of incomplete combustion? Q12 How is acid rain harmful? Q13 Define Explosive Combustion with examples...

LESSON -1 (The Cell – Its structure and Functions) [Source:DAV Ballabhgarh] LESSON -2 (Microorganisms : Friends or Foes ) NOTE—Q.no.1 to 30 carry two marks each.Q.no.31 to 35 carry three marks each. Q.1 Differentiate between chloroplasts and chromoplasts. Q.2 Why were the cells remained undiscovered for a long time? Q.3 Name the unit used to express cell size. Express its value in metres. Q.4 What is the function of albumen and yolk in an egg? Q.5 What is the composition and function of cytoplasm? Q.6 Describe the structure of nucleus. Q.7 What is the importance of cilia and flagella ? Q.8 Describe the various levels of organization. Q.9 Why do plant cells have cell wall? Q.10 Classify the living organisms on the basis of the cell number. Q.11 What advantage does amoeba derive by changing shape? Q.12 A hen’s egg can be seen easily. Is it a cell or a group of cells? Give reason. Q.13 Are the cells in an elephant larger than the cells in a rat? Justify your answer. Q.14 Why do vaccum p...