CBSE ADDA

Topic: The Cell & Fundamental Unit of life MCQ Q.1: The largest cell in the human body is - (a) Nerve cell          (b) Muscle cell  (c) Liver cell   (d) Kidney cell Q.2: The barrier between the protoplasm and the other environment in an animal cells - (a) Cell wall   (b) Nuclear membrane  (c) Tonoplast    (d) Plasma membrane Q.3: The term ‘Cell’ was given by - (a) Leeuwenhoek       (b) Robert hooke        (c) Flemming        (d) Robert Brown Q.4: Who proposed the cell theory? - (a) Schleiden and Schwann     (b) Watson and Crick (c) Darwin and Wallace (d) Mendel and Morgan Q.5: A plant cell differs from an animal cell in the absence of - (a) Endoplasmic Reticulum  (b) Mitochondria (c) Ribosome (d) Centrioles Q.6: Centrosome is found in - (a) Cytoplasm        (b) Nucleus   (c) Chromosomes   (d) Nucleolus Q.7: The power house of a cell is - (a) Chloroplast (b) Mitochondrion  (c) Golgi apparatus  d) Nucleolus Q.8: Within

CBSE EXTRA SCORE NOTES CHAPTER Metals and Nonmeta... : Metals The elements that lose electrons and form positive ions are called metals. They are also called electropositive elements. E.g. sodiu...

class 10 magnetic effect of current NOTES : The region surrounding the magnet, in which the force of the magnet can be detected, is said to have a magnetic field . Why does a compas...

MATH ADDA "10TH MATHS BY JSUNIL": Sample Paper – 2012 Class – X Subject – Mathema... : 1. A motorboat takes 6 hours to cover 100km down stream and 30km upstream. If the motorboat goes 75km down stream and returns back to i... Math Adda

1. What will be the action of the following substances on litmus paper? Dry HCl gas, Moistened NH3 gas, Lemon juice, carbonated soft drink, Curd, Soap solution 2. Name the acid present in ant sting and give its chemical formula. Also give the common method to get relief from the discomfort caused by the ant sting. 3. What happens when nitric acid is added to egg shell?

9th Science chemistry Sample paper Chapter: IS MATTER AROUND US PURE 1. Salt can be recovered from its solution by evaporation. Suggest some other technique for the same? 2. While diluting a solution of salt in water, a student by  mistake added acetone (boiling point 56°C). What technique  can be employed to get back the acetone? Justify your choice. 3. Explain why particles of a colloidal solution do not settle down when left undisturbed, while in the case of a  suspension they do. 4. Smoke and fog both are aerosols. In what way are they different? 5. Name the process associated with the following

1. A solution of potassium chloride when mixed with silver nitrate solution, an insoluble white substance is formed. Write the chemical reaction involved and also mention the type of the chemical reaction? Answer:  KCl (aq) + AgNO3 (aq) → AgCl (s) + KNO3 (aq) It is a double displacement and precipitation reaction. 2. Ferrous sulphate decomposes with the evolution of a gas having a characteristic odour of burning sulphur. Write the chemical reaction involved and identify the type of reaction. Answer:  2FeSO4(s) --H---e---at → Fe2O3(s) + SO2(g) + SO3(g) It is a thermal decomposition reaction 3 . Why do fire flies glow at night? Answer: Fire flies have a protein which in the presence of an enzyme undergoes aerial oxidation. This is a chemical reaction which involves emission of visible light. Therefore, fire flies glow at night. 4. Grapes hanging on the plant do not ferment but after being plucked from the plant can be fermented. Under what conditions do these grape