Life Processes Class-10 Biology 4 Marks Previous Year Questions
Q.1) Kidneys help to regulate the volume of fluid and various metabolites waste products in the body.
Normally, kidney filter about 180 L of fluid daily but the volume actually excreted out is only a litre or two a day.
Patients with kidney failures can be saved by dialysis and kidney transplant.
(a) Write the structure and function of Bowman’s capsule.
(b) Although kidneys filter a large amount (about 180 L daily) of fluids, still the excretion from the body is only about a litre or two. Why ?
(c) What is excretion ? Why is it necessary for any living organism ?
OR
(c) State two similarities between lungs and kidneys.
(a) • Structure → Bowman’s capsule is a cup shaped end of a coiled tube (nephron)
• Function → Bowman’s capsule collects the filtrate from the blood.
(b) Most of the water, salt, glucose, amino acids are selectively reabsorbed from the filtrate into the blood as the urine flows along the tubular part of nephron.
(c) • Excretion is the process of removal of metabolic wastes/ nitrogenous waste/ urea/uric acid from the body.
• It is essential for survival of a living organism as the excretory products are toxic and harmful to the organism.
OR
(c) • Both lungs and kidneys remove metabolic waste /Lungs remove carbon dioxide gas (CO2) from the blood while kidneys remove nitrogenous wastes like urea from the blood.
• Both lungs and kidneys have thin-walled blood Capillaries involved in exchange of gases and filtration of blood respectively.
Q.2) Read the following passage and answer the questions that follow :
Not all plants carry out photosynthesis by the same mechanism. In most plants, it depends directly on gaseous carbon dioxide that diffuses into the leaf. However, some plants can store carbon dioxide in the vacuole of the leaf cells as part of a complex carbon compound. This compound is transported to the chloroplast and releases carbon dioxide when required for photosynthesis. This special mechanism is believed to have evolved as an adaptation in such plants which do not open stomata during the daytime to conserve water for survival in dry conditions (desert conditions).
Attempt either (a) or (b) :
(a) (i) Which process in these plants is minimised to help the plants survive in dry conditions ?
(ii) Which part of the leaf is responsible for exchange of gases during photosynthesis ?
OR
(b) (i) List the events that occur during the process of photosynthesis.
(ii) When are such desert plants likely to take in carbon dioxide from the environment, unlike other plants ?
(iii) Draw a labelled diagram of stomata with open stomatal pore.
(a) (i) Opening of stomata during the day is minimised to prevent loss of water by evaporation. / Transpiration (loss of water in the form of water vapour) is minimised.
(ii) Stomata
OR
(b) (i) • Absorption of light energy by Chlorophyll.
• Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen
• Reduction of Carbon Dioxide into Carbohydrates
(ii) At night.
(iii) Diagram of Open stomatal pore.
Q.1) The maintenance functions of all living organisms must go on even when they are not doing anything particular. Even when we are just sitting in a class or even asleep, this maintenance job has to go on. These maintenance processes require energy to prevent damage and break-down of cells and tissues, which is obtained by the individual organism from the food prepared by the autotrophs, called producers. (1+1+2=4 Marks)
(a) Name and define the process by which green plants prepare food.
(b) Write chemical equation involved in the above process.
(c) (i) State in proper sequence the events that occur in synthesis of food by desert plants.
OR
(c) (ii) Explain giving reasons what happens to the rate at which the green plants will prepare food
(I) during cloudy weather, and
(II) when stomata get blocked due to dust
(a) Photosynthesis A process by which green plants capture sunlight and convert it to chemical energy with the help of chlorophyll / Process by which carbon dioxide and water is converted into carbohydrates in the presence of sunlight chlorophyll and water. (b)
(c)
(i) • Absorption of light energy by chlorophyll
• Conversion of light energy to chemical energy.
• Reduction of carbon dioxide to carbohydrates.
• Desert plants take up CO2 at night and prepare intermediate, which is acted upon by the energy absorbed by the chlorophyll during the day.
OR
(c)
(ii) (I) Decrease the rate of photosynthesis due to low amount of sunlight.
(II) Decreases the rate of photosynthesis due to reduced gaseous exchange.
Q.1) Kidneys are vital organs for survival. Several factors like infections, injury or restricted blood flow to kidneys reduce the activity of kidneys. This leads to accumulation of poisonous wastes in the body, which can even lead to death. In case of kidney failure, an artificial kidney can be used. An artificial kidney is a device to remove waste products from the blood through dialysis.
(a) (i) Name the artery that brings oxygenated blood to the kidney.
(ii) Name the cluster the thin-walled blood capillaries present in the Bowmen’s capsule.
(b) In human excretory system name the organ which stores urine. Is this organ under hormonal control or nervous control ?
(c) (i) List two major steps involved in the formation of urine and state in brief their functions.
OR
(c) (ii) In which part of the nephron does selective reabsorption take place ? List the factors which the amount of water reabsorbed depends on.
(a)
(i) Renal Artery
(ii) Glomerulus
(b)
• Urinary bladder
• Nervous control
(c)
(i) Filtration: Nitrogenous wastes such as urea or uric acid are removed.
Reabsorption: Glucose, amino acids, salts/some useful materials and major amounts of water reabsorbed.
OR
(c)
(ii)Tubular part of nephron.
• The amount of water absorbed depends on:
-how much water is there in the body.
-how much dissolved waste is there to be excreted.
Q.2) Human digestive system is a tube running from mouth to anus. Its main function is to breakdown complex molecules present in the food which cannot be absorbed as such into smaller molecules. These molecules are absorbed across the walls of the tube and the absorbed food reaches each and every cell of the body where it is utilised for obtaining energy.
(a) Name the glands present in the buccal cavity and write the components of food on which the secretion of these glands act upon.
(b) Two organs have a sphincter muscle at their exit. Name them.
(c) What will happen if : (i) mucus is not secreted by the gastric glands. (ii) Villi are absent in the small intestine.
OR
(c) “Bile juice does not contain any enzyme, yet it has important roles in digestion.” Justify the statement.
(a) Salivary glands; Starch / Carbohydrate
(b) Stomach, Anus
(c) (i) The inner lining of the stomach will not be protected from the action of acid.
(ii) Digested food will not be absorbed. / Absorption area will be reduced /
OR
(c) • Emulsification of fats.
• Acidic medium has to be made alkaline for the pancreatic enzymes to act.
Q.1) No Questions
Q.1) The modes by which various organisms reproduce depend on the body design of the organisms. In asexual reproduction, a single individual parent produces offsprings without the involvement of gametes. This method is a common means of increasing the offsprings rapidly under favourable conditions. Asexual reproduction occurs mostly in unicellular organisms, some plants and certain simple multicellular animals.
(a) State the name of the organism in which binary fission takes place in a definite orientation. Also name the disease caused by this organism.
b) List any two advantages of producing plants through vegetative propagation.
(c) (i) Explain the process of budding in Hydra.
OR
(ii) What happens when
(I) a spirogyra filament matures and attains a considerable length, and
(II) a sporangia in Rhizopus bursts on maturation ?
(a) Leishmania, Kala-azar
(b) Plants can bear fruits and flowers much earlier than produced by sexual reproduction Plants produced are genetically similar to the parent plant (Or any other) (c) (i) Bud develops as an outgrowth due to repeated cell division at one specific site, these buds develop into tiny individuals, and when fully mature detach from the parent body and become new independent individuals.
(a well labelled diagram can also be made)
OR
(c) (ii)
(I) The filament breaks into smaller pieces or fragments and each fragment grows into new individuals.
(II) It releases spores which germinate and eventually develops into new Rhizopus individuals.
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