Monday 30 July 2018

Class 8: CELLS STRUCTURE AND FUNCTIONS

Practice Paper
Subject Biology
Class VIII                  Ch- CELLS STRUCTURE AND FUNCTIONS                               
  1. Mention the layer outside the plasma membrane of a plant cell.
  2. Name the outermost layer of an animal cell.
  3. Name the cells having branching structure.
  4. Why cells could not be observed before seventeenth century?
  5. What is the basic structural and functional unit of all living organisms?
  6. Which organism has the smallest cell?
  7. Which is the largest cell visible by unaided eye?
  8. Name the four elements, which form major part of protoplasm.
  9. Give two examples of unicellular organisms.
  10. Name the jelly like substance present between the nucleus and the cell membrane.
  11. Name the living substance of the cell.
  12. Which organelle is called control centre of the activities of the cell?
  13. Give two examples of prokaryotes.
  14. Name the largest organelle present in a cell.
  15. Name the green plastids present in cell. 
  16. Write a brief note on mitochondria.
  17. Why do we stain the small components of section, before seeing under the microscope? Name a stain.
  18. Name any four cell organelles found in the cell cytoplasm?
  19. Why is the cell called basic unit of living organism?
  20. What is the function of cell membrane?
  21. What is the function of nerve cell?
  22. What are the basic components of cell?
  23. Why plant cell have cell wall?
  24.  Describe the variations in shape and size of cells.
  25. Explain why chloroplasts are found only in plant cells?
  26. Write the functions of the following :
    a) Mitochondria b) Chromosomes c) Plastids.
  27. Write three differences between prokaryotic and eukaryotic cells.
  28. Where are chromosomes found in a cell? State their function.
  29. Draw the diagram of plant and animal cell.
  30. Make a sketch of the human nerve cell. What function do nerve cells perform
  31. Write short notes on the following: a)Cytoplasm b) Nucleus
  32. Differentiate between plant and animal cell.

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Monday 16 July 2018

Ray Optics Class 12


1. A biconvex lens made of a transparent material refractive index 1.25 is immersed in water of refractive index 1.33. Will the lens behave as a converging or a diverging lens? Give reason.
2. A biconvex lens made of a transparent material of refractive index 1.5 is immersed in water of refractive index 1.33. Will the lens behave as a converging or diverging lens? Give reason.
3. A convex lens is placed in contact with a plane mirror. A point object at a distance of 20 cm on the axis of this combination has its image coinciding with itself. What is the focal length of the lens?
4. Write the relationship between angle of incidence i, angle of prism A and angle of minimum deviations from a triangular prism.
5. How does focal length of a lens change when red light incident on it is replaced by violet light? Give reasons for your answer. 
6. Name the physical quantity which remains same for micro waves of wavelength 1 mm and UV radiation of 1600 A in vacuum.

7. Under what condition, does a biconvex lens of glass having a certain refractive index act as a plain glass sheet when immersed in a liquid?
8. For the same value of angle of incidence, the angle of refraction in three media A, B and C are 15°, 25° and 35° respectively. In which medium, would the velocity of light be minimum?
9. When monochromatic light travels from one medium to another, its wavelength changes but frequency remains the same. Explain.
10. The refractive index of diamond is much greater than that of glass. How does a diamond cutter make use of this fact?
11. If a ray propagates from a rarer to a denser medium, how does its frequency change?
12. State the criteria for the phenomenon of total internal reflection of light to take place.
13. A lens behaves as a converging lens in air and a diverging lens in water (g = 4/3). What will be the condition on the value of refractive index (g) of the material of the lens?
14. A converging lens axially in contact with a diverging lens; both the lenses being of equal focal length. What is the focal length of the combination?
15. A glass lens of refractive index 1.45 disappears when immersed in a liquid. What is the value of refractive index of the liquid?
16. Calculate the speed of light in a medium whose critical angle is 30°.
17. Why does the sky appear blue?
18. Under what condition does the formation of rainbow occurs?
19. Two thin lenses of power +6D and -2D are in contact. What is the focal length of the combination?
20. Two thin lenses of power + 4D and -2D are in contact. What is the focal length of the combination?
21. Two thin lenses of power +5D and -2.5D they are in contact what is the focal length of the combination?
22. Why are convex mirrors used as side view mirrors in cars? 
23. A converging lens of refractive index 1.5 is kept in a liquid medium having same refractive index. What would be the focal length of the lens in this medium?
24. How does the power of convex lens vary if we incident red light is replaced by violet light?
25. Explain giving reason why the sun looks reddish at sunrise and sunset? 
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CLASS 9

 Important Questions for ICSE Class 9 Science, Chapter WIse Questions. 

 CLASS 9 - PHYSICS


 CLASS 9 - CHEMISTRY

    3. ATOMIC STRUCTURE


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CLASS 8

 PHYSICS         

       1. MATTER                                 

      2. PHYSICAL QUANTITY

      3. FORCE AND PRESSURE

      4. WORK & ENERGY  

       5. LIGHT: REFRACTION OF LIGHT        
         
      CHEMISTRY

     1. LANGUAGE OF CHEMISTRY
  
     2. MATTER
  
    3. CHEMICAL REACTIONS

    4. ELEMENT AND COMPOUND

    5. ATOMIC STRUCTURE

     BIOLOGY

    1. TRANSPORTATION
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Saturday 14 July 2018


CBSE -NCERT  IMPORTANT QUESTIONS OF SCIENCE WITH SOLUTIONS



CBSE - NCERT Previous Years Question Papers, Quick Views & Solutions For Class 10

  Chapter 1 - Chemical Reactions and  EquationsQuick  viewSolutions
  Chapter 2 - Acid, Bases and SaltQuick ViewSolutions
  Chapter 3 - Metal and Non-metalsQuick ViewSolutions
  Chapter 4 - Carbon and it's compoundQuick ViewSolutions
  Chapter 5 - Periodic Classification of ElementsQuick ViewSolutions
  Chapter 6 - Life ProcessesQuick ViewSolutions
  Chapter 7 - Control and Co-ordinationQuick ViewSolutions
  Chapter 8 - How do Organisms Reproduce?Quick ViewSolutions
  Chapter 9 -  Health and HeredityQuick View
  Chapter 10 -  Reflection and RefractionQuick ViewSolutions
  Chapter 11 -  Human Eye Colourful WorldQuick ViewSolutions
  Chapter 12 -  ElectricityQuick ViewSolutions
  Chapter 13 -  Magnetic Effect of Electric CurrentQuick ViewSolutions
  Chapter 14 -  Sources of EnergyQuick ViewSolutions
  Chapter 15  - Our EnvironmentQuick ViewSolutions
  Chapter 16 - Management of  Natural  ResourcesQuick ViewSolutions


    

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Important Questions for CBSE 9 Science,Chapter Wise Questions and Solutions

CBSE -NCERT  IMPORTANT QUESTIONS OF SCIENCE WITH SOLUTIONS




CBSE - NCERT Previous Year Question Papers For Class 9 
CHAPTER 1 - MATTER IN OUR SURROUNDINGS QUESTION WITH SOLUTIONS
CHAPTER 2 - IS MATTER AROUND US PURE? QUESTION WITH SOLUTIONS
CHAPTER 3 - ATOMS AND MOLECULES QUESTION WITH SOLUTIONS
CHAPTER 4 - STRUCTURE OF ATOM QUESTION WITH SOLUTIONS
CHAPTER 5 -  THE FUNDAMENTAL UNIT OF LIFE QUESTION WITH SOLUTIONS
CHAPTER 6 -  TISSUE
CHAPTER 7 -   DIVERSITY IN LIVING ORGANISM
CHAPTER 8 -  MOTION  QUESTION WITH SOLUTIONS
CHAPTER 9 -  FORCE AND LAW OF MOTION QUESTION WITH SOLUTIONS
CHAPTER 10 - GRAVITATION    QUESTION WITH SOLUTIONS
CHAPTER 11 -  WORK AND ENERGY
CHAPTER 12 -  SOUND
CHAPTER 13-  WHY DO WE FALL ILL
CHAPTER 14 - NATURAL RESOURCES
CHAPTER 15 - IMPROVEMENT OF FOOD RESOURCES


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Important Questions for CBSE 8 Science,Chapter Wise Questions

CBSE -NCERT  IMPORTANT QUESTIONS OF SCIENCE 





CBSE - NCERT Previous Year Question Papers For Class 8


CHAPTER 1 - CROP PRODUCTION AND MANAGEMENT
CHAPTER 2 - MICRO-ORGANISMS
CHAPTER 3 -  SYNTHETIC, FIBRES AND PLASTICS
CHAPTER 4 -  MATERIALS-METALS AND NON-METALS 
CHAPTER 5 -  COAL AND PETROLEUM
CHAPTER 6 -  COMBUSTION AND FLAME
CHAPTER 7 - CONSERVATION OF PLANTS AND ANIMAL
CHAPTER 8 - CELL - STRUCTURE AND FUNCTIONS
CHAPTER 9 - REPRODUCTION IN ANIMALS
CHAPTER 10 - REACHING THE AGE OF ADOLESCENCE
CHAPTER 11 - FORCE AND PRESSURE
CHAPTER 12 - FRICTION
CHAPTER 13 - SOUND
CHAPTER 14 - CHEMICAL EFFECTS OF E.C
CHAPTER 15 - SOME NATURAL PHENOMENA
CHAPTER 16 - LIGHT
CHAPTER 17 - STARS AND SOLAR SYSTEM
CHAPTER 18 -  POLLUTION OF AIR AND WATER 
                                                             





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Monday 2 July 2018

HEREDITY AND EVALUATION 10

PRACTICE PAPER
      SUBJECT BIOLOGY (2018) 
      HEREDITY AND EVALUATION
CLASS X
______________________________________________
      
I. Very short answer type questions: 
  1. Why do all the gametes formed in human females have an X-chromosome?
  2. In which type of reproduction, the exchange of genetic material takes place?
  3. In evolutionary terms, can we say which among bacteria, spiders, fish, and chimpanzees have a better body design? Why or why not?
  4. Two pink coloured flowers on crossing resulted in 1 red and 2 pink and 1 white flower progeny. What will be the nature of the cross?
  5. A cross between a tall plant (TT) and a short pea plant (tt) resulted in progeny that were all tall plants. Why?
  6. A very small population of a species faces a greater threat of extinction than a larger population. Provide a suitable genetic explanation.
  7. In turtle, high incubation temperature leads to the development of female offspring. On the other hand in lizard, high incubation temperature leads to the development of male offspring. What determines the sex of the offspring in this example?
  8. What are homologous structures? Give an example?
  9. If the weight of an elephant is reduced because of starvation, the progeny elephants will not have a low weight. Give reason.
  10. How does the creation of variation in a species promote survival?
  11. How was the vegetable kale obtained from cabbage?
  12. 70% of vegetables in a population of hydra show long tentacles, whereas 10% of individuals in the same population show short tentacles. Which trait is likely to have arisen earlier?
  13. In a cross between round yellow seeds (RRyy) and wrinkled green seeds (rryy) of pea plant, what is the ratio of plants obtained in F2 generation?
  14. What is the only progressive trend seen in the environment?
  15. How do genes control traits?
  16. When a black guinea pig is crossed with a white guinea pig, what coloured guinea pig are obtained in F1 if the black colour is dominant over white?
  17. How does compare the DNA of different species help in evolutionary studies?
  18. In a cross between a tall pea plant TT and a short pea plant tt, what will be the characteristics are shown by the F1 generation?
  19. List any two factors that could lead to speciation.
  20. What is speciation?
  21. Write the contribution of Charles Darwin in the field of evolution.
  22. Name the information source for making proteins in the cell.
  23. Give the respective scientific terms used for studying: 
    (i) The mechanism by which variations are created and inherited and
    (ii) The development of a new type of organism from the existing ones.
  24. No two individuals are absolutely alike in population. Why?
  25. What is heredity? 
  26. What is gene?
II. Short answer type questions: 
  1. Does genetics combinations of mothers play a significant role in determining the sex of a newborn?
  2. Name three important features of fossils that help in the study of evolution.
  3. Explain the importance of fossils in deciding evolutionary relationships.
  4. A woman has only daughters. Analyze the situation genetically and provide a suitable explanation.
  5. A man with blood group A marries with a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits blood group A or O is dominant? Why or why not?
  6. Give two instances of spaces where geographical isolation does not lead to any specification.
  7. Name any four mechanisms which can lead to speciation in sexually reproducing organisms. If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which state is likely to have arisen earlier?
  8. Where are genes located? What is the chemical nature of the gene?
  9. During the crossing, why do new features which are not present in the parents appear in the offspring?
  10.  What are their characteristics? Give an example.
  11.  Organisms showing Asexual Reproduction show very little variation from each other. Why?
  12. Why each gamete contain only one gene set?
  13. What is the difference between F1 generation and F2 generation?
  14. State two methods of determining the age of fossils.
  15. Write a full form of DNA. Where is it located?
  16. In area A, the leaf material available to beetle was very less. What are the two consequences seen in the beetle?
  17. Can a wing of a butterfly and wing of a bat be considered homologous organs? Why or why not?
  18.  Give an example of characteristics being used to determine how close two species are in the evolutionary term.
  19. How does natural selection differ from genetic drift?
  20. What do the following terms mean? (i) Microevolution (ii) Fossils.
  21. How is the equal genetic contribution of male and female parents ensured in the progeny?
  22. How are areas of study of evolution and classification interlinked?
  23. Why are traits acquired during the lifetime of an individual not inherited?
III.Long answer type questions: 
  1. Why the small number of surviving tigers are causes of worry from the point of view of genetics. Explain.
  2. In the following cross, write the characteristics of the progeny cross
    (a) RRYY x RRYY  (b) RrYy x RrYy   (c) rryy x rryy   (d) RRYY x rryy
  3. Give the basic features of the mechanism of inheritance.
  4. When organisms die, their bodies will decompose and be lost. Then how do we get fossils? Give an example.
  5. Define evolution. Why are traits acquired during a lifetime on an individual not inherited?
  6. Differentiate between inherited characters and acquired characters.
  7. Differentiate between dominant and recessive traits. Gene control traits. Explain this statement with examples.
  8. In Mendel’s monohybrid cross between tall and short tea plants, all offspring was tall. What does this tell us about the trait? What is the ratio of tall and short plants in the F2 generations?
  9. Name the descendants of wild cabbage dot. How are they developed?
  10. Trace the  F1 generation formed by crossing two plants with separate traits for shape and seed colour round green RRyy and wrinkle yellow rryy. Mention the characteristics exhibited by it.
  11. Name two factors that could lead to the rise of new species. Why the wings of birds and bats are considered analogous organs?
  12. With the help of a cross done with garden pea plants, trace the work done by Mendel with a tall and short plant to arrive at a 3:1 ratio in the F2  generation.
  13. The genotype of green stemmed tomato plants in denoted by GG and that of purple stemmed tomato plants as gg. When these two plants are crossed:
    (a) What colours of steam would you expect in their F1 progeny?
    (b) Give the percentage of purple stemmed plants if F1 plants are self-pollinated. 
    (c) In what ratio would you find the green and purple colour in the F1 progeny?
  14. How do Mendel's experiments show that traits may be dominant or receives?
  15. Define Genetics. Who is regarded as the 'Father of Genetics'? Name the plant on which the performed his experiment.
  16. Why did he select that specific plant for his experiments?
  17. Name the unit of inheritance. What are its functions? How are inherited traits different from an acquired trait? Give an example.
  18. What are fossils? How do we know how old the fossils are?
  19. State two differences between homologous and analogous organs.
  20. Give two uses of fossils. How does the study of fossils provide evidence in favour of organic evolution?
  21. Which of the following is invertebrate and which one is vertebrate (a)Dinosaur  (b) Ammonite.
     How can the age of fossils be ascertained? State in brief any two methods.
  22. Show Inheritance of two characters over two generations by making a cross between a round and yellow seeded plant RRrr with a wrinkled green seeded plant. rryy.
  23. In a cross between plants with purple flowers and plants with white flowers of offspring of F1 generation all had white flowers. When the F1 generation was self-crossed, it was observed in the F2 generation that out of 100, 75 flowers were white. Make a cross and answers the following, 
    (i) What are the genotypes of F2 progeny? 
    (ii) What is the ratio of white purple flowers in the F2 generation?
  24. A husband has 46 chromosomes, his wife has 46 chromosomes. Then why don't their offsprings have 46 pairs of chromosomes, which is obtained by the fusion of male and female gametes?
  25. Geographical isolation is not a major factor in the speciation of a self-pollinating plant species. Justify this statement with the help of an example.
  26. How were farmers able to obtain present-day cabbage, cauliflower and broccoli from wild cabbage?
  27. (i) What is meant by the traits of an individual?  
    (ii) Explain inheritance traits and acquired traits.
    (iii) Define specifications. List the factors which could lead to the rise of a new species.
  28. Why are two-letter such as TT, Tt, tt used to denote the character of height? If a purple pea plant PP is crossed with a white coloured pea plant pp, will we have white-flowered pea plant in the F1 generation? Why? Define dominant and recessive traits.
  29. What evidence do we have for the origin of life from inanimate matter?
  30. A particular species X has more common characteristics with species Y , whereas another species Z has less common characteristics with species Y.
  31. Which two species are more closely related? And Why?
  32. On what basis are the eukaryotic organisms further classified? Why is this basis important?
  33. What is the importance of homologous organs?
  34. (a) Some dinosaurs have feathers but could not fly using these feathers. Why?
    (b) What is inherited and acquired traits? 
    (c) What is the sex chromosome?
  35. A blue colour flower plant denoted by BB is crossed with a white flower plant denoted by ww.
    (a) State the colour of flower we would expect in their F1 progeny.
    (b) Write the percentage of the plants bearing white flower in F2 generation when the flowers of F1 plants were selfed. State the expected ratio of the genotype BB and BB is the F2 progeny.
  36. A cross was carried out between a purebred tall pea plant and a purebred dwarf pea plant and F1 progeny was obtained. Later, the F1 progeny was selfed to obtain F2 progeny. Answer the following questions: 
    (a)What is the phenotype of the F1 progeny and why?
    (b) Give the phenotype ratio of the F2 progeny 
    (c)Why is the F2 progeny different from the F1 progeny?
  37. Explain with the help of suitable examples of why certain traits cannot be passed onto the next generation. What are such traits called?
  38. What are fossils? State their importance in the study of evolution with the help of suitable examples.
  39. Tabulate the difference between acquired traits and inherited traits with one example of each.
  40. Evolution should not be equated with progress why?
  41. The modern human beings have originated in Africa. Which evidence suggested this fact? If the animal is similar to its ancestors, what does this imply?
  42. Name three organisms that are fossilized.
  43. In human beings, the statistical probability of getting either male or a female child is 50%. Give reasons and explain with the help of a diagram.
  44. Differentiate between homologous and analogous organs. Give one example of each.
  45. Define the following with one example for each: 
    (a) Genetic drift. (b) Natural selection.(c) Reproductive isolation.
  46. Mendel crossed tall pea plants with dwarf pea plants in his experiment. Write his observations giving reasons on the F1 and F2  generation.
  47. List any two contrasting characters other than height and Mendel used in his experiments in pea plants.
  48. A cross was made between pure breeding pea plants one with round and green seeds and the other with wrinkled and yellow seeds.
  49. Write the phenotype of F1 progeny. Give reasons for your answer.
  50. Write the different type of F2 progeny obtained along with their ration when  F1 progeny was selfed.
  51. Give the evidence that the bird has evolved from reptiles. Insects, Octopus, Planaria and Vertebrates possess eyes.
  52. Can we group these animals together on the basis of eyes that they possess? Justify your answer giving reasons?
  53. List three main factors responsible for the specification and briefly describe each of them. How sex is determined in human beings?
  54. "It is a matter of chance whether a couple will give birth to a male child or a female child". Justify this statement with the help of a flow chart showing the fusion of sex chromosomes.
  55. With the help of suitable examples, explain why certain tastes cannot be passed on to the next generation. What are such traits called?
  56. "The chromosomes number of the sexually reproducing parents and their offspring is the same". Justify this statement.
  57. ”A trait may be inherited, but we do not be expressed. “Justify this statement with the help of a suitable example.
  58. Why cannot be experiences of an individual during its lifetime be passed on to its progeny?

  Chapter 1 - Chemical Reactions and  EquationsQuick View  Questions with Solutions
  Chapter 2 - Acid, Bases and SaltQuick View   Questions with Solutions
  Chapter 3 - Metal and Non-metalsQuick View   Questions with Solutions
  Chapter 4 - Carbon and it's compoundQuick View   Questions with Solutions
  Chapter 5 - Periodic Classification of ElementsQuick View   Questions with Solutions
  Chapter 6 - Life ProcessesQuick View   Questions with Solutions
  Chapter 7 - Control and Co-ordinationQuick View   Questions with Solutions
  Chapter 8 - How do Organisms Reproduce?Quick View   Questions with Solutions
  Chapter 9 -  Health and HeredityQuick View
  Chapter 10 -  Reflection and RefractionQuick View   Questions with Solutions
  Chapter 11 -  Human Eye Colourful WorldQuick View   Questions with Solutions
  Chapter 12 -  ElectricityQuick View   Questions with Solutions
  Chapter 13 -  Magnetic Effect of Electric CurrentQuick View   Questions with Solutions
  Chapter 14 -  Sources of EnergyQuick View
  Chapter 15  - Our EnvironmentQuick View
  Chapter 16 - Management of  Natural  ResourcesQuick View



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