Life Processes Class-10 Biology 5 Marks Previous Year Questions
Q.1) (a) Draw a labelled diagram showing open and closed stomatal pore.
(b) List the main events that occur during the process of photosynthesis.
(c) Write a balanced chemical equation showing photo-synthesis in plants.
(a)
(b) • Absorption of light energy by chlorophyll.
• Conversion of light energy to chemical energy and splitting of water molecule into hydrogen and oxygen.
• Reduction of carbon dioxide to carbohydrates.
(c)
Q.2) (a) Draw a well-labelled diagram of nephron and label at least 4 of its parts.
(b) Write the role of capillary cluster inside Bowman’s capsule.
(c) What is meant by selective reabsorption?
(a)
(b) Filtration of blood to remove wastes.
(c) It is a process by which useful substances like glucose, amino acids, vitamins, salts and most of water are reabsorbed from filtrate, back into the blood.
Q.1) (i) “The length of the small intestine in various animals depends on the food they eat.” Justify the statement.
(ii) Discuss the role of the pancreas and bile juice in the digestion of food in human beings.
(iii) How is the small intestine designed to absorb digested food ?
(i) Animals (Herbivores) eating grass need a longer small intestine to digest cellulose. Meat is easier to digest, hence ṃeat eating animals (Carnivores) have shorter small intestine.
(ii) Role of Pancreas – Secrete pancreatic juice which contains trypsin for digesting proteins, lipase for breaking down emulsified fats. Role of Bile- Bile emulsifies fats and makes the medium alkaline in the small intestine so that pancreatic enzymes can act.
(iii) The inner lining of the small intestine has numerous finger-like projections called villi which increase the surface area for absorption of food. The villi are richly supplied with blood vessels which take the absorbed food to each and every cell of the body.
Q.2) (i) State the role of rings of cartilage present in the throat.
(ii) Discuss the role of the ribs and diaphragm when air is taken in during the breathing cycle.
(iii) Why do we get muscle cramps during heavy exercise ? Explain.
(i) ‘Rings of cartilage’ ensures that the air passage does not collapse in absence of air.
(ii) Ribs are lifted → Diaphragm flattens → Chest cavity become larger → Air is sucked into the lungs (Alveoli) and we breathe in
(iii) Due to lack of oxygen in our muscle cells (anaerobic respiration), pyruvate is converted into lactic acid, build-up of lactic acid in our muscles causes cramps.
Q.1) Study the following flow chart showing the breakdown of glucose by various pathways. In this flow chart, in four blocks some blanks are given as A , B , C and D .
(i) Write the names of A , B , C and D .
(ii) Write the source of glucose molecule involved in cellular respiration in (I) plants, and (II) animals.
(iii) Why do athletes sometimes suffer from muscle cramps during running ?
(iv) Give reason why the rate of breathing in aquatic organisms is faster than in terrestrial organisms.
(i) A – Pyruvate
B – Ethanol
C – Muscle cells
D – Mitochondria
(ii) (I) Plants – Starch
(II) Animals – Glycogen
(iii) Due to lack of oxygen, pyruvic acid is converted to lactic acid which accumulates in their muscle cells. so causes cramps.
(iv) Amount of dissolved oxygen in water is low as compared to amount of oxygen in air, so the rate of breathing is more to get required oxygen in aquatic animals.
Q.2) (i) Given below is a diagram showing cross-section of a leaf. Name the parts marked as A and B and write one specific function of each.
(ii) Name the two tissues present in a vascular bundle. In what way does each of them help a plant ?
(iii) In the experiment “Light is essential for photosynthesis”, why does the uncovered part of the leaf turned blue-black after putting iodine solution on it ?
(i) A – Chloroplast
B – Guard cells
Functions: A – contain chlorophyll pigment to absorb light during photosynthesis.
B – Regulate opening and closing of stomatal pore.
(ii) Xylem and Phloem
Functions: Xylem – transport water and minerals from soil to other body parts
Phloem – Transport carbohydrates as food from leaves to other body parts / translocation
(iii) Uncovered part of leaf receive light during photosynthesis and produce starch which on reacting with iodine make the leaf blue black in colour.
Q.3) (i) Study the diagram below of alimentary canal of man and name the parts marked as A, B and C. Write the name of the enzyme present in each labelled part.
(ii) Explain how digested food reaches each and every cell of the body and is utilised.
(i) A – Mouth/buccal cavity
B – Stomach
C – Pancreas
Enzymes
A – Salivary Amylase
B – Pepsin
C – Trypsin/Lipase
(ii)• Digested food is taken up by the walls of the small intestine/ villi
• The food is absorbed here
• Blood vessels in the villi take absorbed food to each and every cell of the body.
• Utilisation of this food is done to obtain energy, building up new tissues and repair of old tissues.
( it can be explained in paragraph form also)
Q.4) (i) Study the diagram below showing schematic representation of transport and exchange of gases in human heart and name the parts labelled as A, B and C. Mention the function of each part.
(ii) Explain how separation of right and left side of the heart is useful for birds.
(i)
A – Pulmonary artery
B – Aorta
C – Capillaries
Functions:
A – Carries deoxygenated blood from heart to lungs.
B – Carries oxygenated blood to different parts of the body.
C - Exchange of material between blood and surrounding parts.
(ii)
• To prevent oxygenated and deoxygenated blood from mixing
• This allows a highly efficient supply of oxygen to the body of birds to maintain their body temperature.
Q.5) Design an experiment to demonstrate that carbon dioxide is essential for photosynthesis. Write the observation and conclusion of the experiment.
• Take two healthy potted plants, A and B of nearly the same size.
• Keep them in darkness for three days. (Destarch the plant)
• Place a watch glass containing potassium hydroxide by the side of potted plant A but not in potted plant B.
• Cover both the plants with separate bell jars and seal the bottom of the jars with Vaseline.
• Keep both the plants in sunlight for two hours.
• Pluck one leaf each from both the plants and test for the presence of starch with iodine solution.
• Observation: The leaf of the potted plant A with KOH did not turn blue – black. The leaf of the potted plant B turns blue.
• Conclusion: KOH absorbs CO2 so photosynthesis did not occur in potted plan.
Q.6) (i)
In the experimental set-up shown above in diagram (I) atmospheric air is being passed into lime water with a syringe while in diagram (II) air is being exhaled into lime water. The time taken for the lime water to turn milky in both the test tubes is different. Give reason.
(ii) Draw the diagram of an open stomatal pore and label (I) Guard cells, and (II) Chloroplast on it. Mention two functions performed by stomata.
(i) In set up (I) lime water turns milky in more time as compared to set up (II) because the air we exhaled contains high percentage of CO2 as compared to atmospheric air.
(ii)
Two labellings :
(I) Guard Cells (II) Chloroplast
Two functions performed by stomata :
• Gaseous exchange
• Transpiration
Q.1) No questions
Q.1) No questions
0 Comments