LIFE PROCESSES – 3 Mark Questions

Q1. What are the adaptations of leaf for photosynthesis?

Q2.  State the function of the following in the alimentary canal

(i)   Liver (ii)   Gall bladder             (iii) Villi

Q3. (i) A product is formed in the cytoplasm of our muscles due to breakdown of glucose when there is a lack of oxygen. Name the product and also mention the effect of build-up of this product.

         (ii) Differentiate between fermentation in yeast and aerobic respiration on the basis of end products formed.

Q4. What is the logic behind the heavy breathing as we climb up a mountain?

Q5.  What is the role of respiratory pigment in respiration? Give one example.

Q6. State reason for the following:

               (i) Arteries have thick and elastic walls

               (ii) Arteries form capillaries

Q7. Describe translocation?  How does translocation take places in plants?         

Q8. Major amount of water is selectively reabsorbed by the tubular part of nephron. Write the factors on which the amount of water reabsorbed depends?          

Q9.         (i)  Write the important functions of the structural and functional unit of kidney.

                 (ii)   Write any  one  function  of  an  artificial kidney:             

Q10. State the necessary conditions for autotrophic nutrition and name the by-product. Mention the source of this by-product.

Q11. Enumerate three events which occur during the process of photosynthesis.

Q12. Sweet tooth may lead to tooth decay. Explain why? What is the role of toothpaste in preventing cavities?

Q13. Name three different glands associated with the digestive system in humans. Also, name their secretions.

Q14. List the role of each of the following in our digestive system:

(i) Muscles of Stomach wall

(ii) Hydrochloric acid

(iii) Mucus.

Q15. A variegated leaf with green and yellow patches is used for an experiment to prove that chlorophyll is required for photosynthesis.   Before the experiment, the green portions (A), and the pale-yellow portions (B), are observed. What will be the colour of ‘A: just before and after the starch test? Also write the equation of photosynthesis and mark, as well as validate from which molecule the by-product is obtained.

Q16. Define breathing. Explain the mechanism of breathing in human beings.

Q17. List three characteristics of lungs which make it an efficient respiratory surface.

Q18. Define transpiration. State its two functions.

Q19. (a) How does the transport of materials in xylem and phloem occurs?

           (b) What is translocation?

Q20. (a) What is lymph?

            (b) How is composition of lymph different from blood plasma?

            (c) List two functions of lymphatic system.

Q21. (i) Why do ventricles have thicker, muscular walls than atria?

            (ii) What are peristaltic movements?

           (iii) ‘Stomata remain closed in desert plants during day time.’ How do they do photosynthesis?

Q22. Give reasons for: –

(i) Oxygenated and deoxygenated bloods are separate in the heart of mammals.

(ii) Ventricles are thick-walled.

(iii) Herbivores have longer small intestine as compared to carnivores.

Q23. Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their functioning and structure.

Q24. How do leaves of plants aid in excretion?

Q25. (a) Why does the transport of food in plants require living tissues and energy?

            (b) Name the components of food that are transported by the living tissues.

Q26.  Given below is a diagram showing a section of the human heart.

(a) Identify the parts labelled as X, Y and Z in the above figure.

(b) Among the following given blood vessels, identify those

          (i) which carry oxygenated blood.

         (ii) which carry deoxygenated blood.

‘Pulmonary artery, Pulmonary vein, Aorta, Vena cava.’

Q27. Our body produces various waste products through different processes. List the waste products with the organs involved in their removal.

Q28. (a) The diagram given below shows parts of the human respiratory system. Identify and name the parts labelled as A-B in the figure.

        (b) Explain the working of lungs as organs of excretion.

Q29.  Which feature(s) help the plants to make food by the process of photosynthesis?

Q30.  ‘Aerobic respiration produces more ATP than anaerobic respiration’. Justify this statement.

Q31.    Write the pathway of oxygen travelling from atmosphere into the human body.

Q32.  ‘Diffusion pressure cannot deliver oxygen all over the body in bigger animals’.  Comment on this statement.

Q33.   Blood does not clot in the blood vessels. Give reason.

Q34.   How is double circulation different from single circulation?

Q35.   Explain, how the circulatory system carries waste products from liver to the kidneys?                    

Q36.  Explain the process by which plants get rid of their excretory products?

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