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BIOLOGY YEAR 10 EXAMS FOR CAMBRIDGE IGCSE EXAMS

  1. Define
  2. 1. enzyme   [1]

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  • Describe the effects of temperature on rate of enzyme controlled reaction in terms of kinetic energy, active site and frequency of effective collisions                                                                     [ 3]

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  • List 3 properties of enzymes. [ 3]

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d) Describe how an enzyme functions. Include the terms such as substrate, active site, product, enzyme-substrate complex [5]

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d) State the substrate of each of the following enzymes [3]

lactase …………………………………………………………

lipase …………………………………………………………

maltase ………………………………………………………… 

                                                                                           [Total 15]

  • Define photosynthesis.                   1 mark

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A. Write down a balanced chemical reaction for photosynthesis [1]

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B. Describe the role of chlorophyll in photosynthesis   [2]

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C
B
A

C. The graph below shows rate of photosynthesis reactions that were taken in different conditions. Study them and answer questions that follow.      

1. What do you understand by the term limiting factor? [1]                   

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2. In experiment A, Light is not the limiting factor. Using your definition above, describe why. [1]

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3.   Why is in experiment C, further increase in temperature leads to abrupt fall of rate of photosynthesis to zero. [1] ………………………………………………………………………………

4. Describe the 3 fates of glucose formed in a plant. [3] ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

  • 1. State the dietary importance of the following foods. [3]

a. Carbohydrates

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b. proteins

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c. oils

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2. State any 2 effects of malnutrition to a human being [2] ………………………………………………………………………………

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                                                                                                       [Total=15]   

  • a. Define the term assimilation in relation to nutrition. [1]

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b. describe briefly the difference between mechanical digestion and chemical digestion of bread limited to digestion in the mouth Hint. Bread contains starch. [4]

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c. during a cholera outbreak. The patients were found to be losing a lot of water. Describe how the cholera bacterium worked to bring this effect. [3] ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

  1. Name any 4 types of teeth and in each give its characteristic feature that distinguishes it from the other tooth      [4]

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  • Describe the process that leads to decay of teeth and state one way of preventing tooth decay                                                [3].

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  • State any 2 uses of Hydrochloric acid in the stomach. [2]

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d. Bile is a liquid that is produced in the small intestine. It contains salts, Sodium hydrogen carbonate and some enzymes. State the role of bile in digestion. [3]

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                                                                                           [Total 20]

  • 1. State the functions of the following in plants
  • Xylem and phloem [2]

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  • Root hair cells [1]

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  • Spongy mesophyll layer in leaves [1]

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2. Describe the pathway taken by water from the soil to the roots. [6]

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3. Define translocation. [2]

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4. In a year, Some parts of the plants can behave like a sink while in other times like a source. By use of an example, describe this statement. [3]

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 [Total 15]

  • 1. Differentiate between the following terms.

a. Single circulation and double circulation [2]

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b. Translocation and transpiration [2] ………………………………………………………………………………………………………………………………………………………………

2. Describe the advantage of double circulation over single circulatory [1].

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3. State the reason behind the following.          

1. Relative thickness of muscle of atria to that of ventricles        [2] ………………………………………………………………………………………………………………………………………………………………

2 . Relative thickness of muscle of vein and that of artery           .

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          3. Describe any other 3 adaptations of the heart apart from the ones named above.  [6]

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4. Describe how a coronary heart disease [CHD] develops [4]

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5. State three ways that one can use to prevent CHD [3]

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6. Name three ways that can be used to treat CHD [3]

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  • In an experiment to determine the heart rate of different individuals during exercise, it was found that the rate of heart rate was affected by several factors

1. Name any 2 methods that can be used to check heart rate. [2]

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