Exam Question for Class 10 Science Chapter 6 Life Processes
Please refer to below Exam Question for Class 10 Science Chapter 6 Life Processes. These questions and answers have been prepared by expert Class 10 Science teachers based on the latest NCERT Book for Class 10 Science and examination guidelines issued by CBSE, NCERT, and KVS. We have provided Class 10 Science exam questions for all chapters in your textbooks. You will be able to easily learn problems and solutions which are expected to come in the upcoming class tests and exams for standard 10th.
Chapter 6 Life Processes Class 10 Science Exam Question
All questions and answers provided below for Exam Question Class 10 Science Chapter 6 Life Processes are very important and should be revised daily.
Exam Question Class 10 Science Chapter 6 Life Processes
Very Short Answer Type Questions:
Question: If human urine is allowed to stand for sometime, it smells of ammonia, why?
Answer: Urea present in urine gets decomposed into ammonia by the action of bacteria. So it smells strongly of ammonia.
Question: In which form do plants store the carbohydrates which are not used immediately?
Answer: Plants store carbohydrates which are not used immediately in the form of starch.
Question: Name the two ways in which glucose is oxidized to provide energy in various organisms.
Answer: The two ways in which glucose is oxidized to provide energy in various organisms are Aerobic respiration and Anaerobic respiration. into a new complete organism.
Question: Name an enzyme present in pancreatic juice.
Answer: Lipase, Trypsin
Question: Define parasitic nutrition. Name an organism having parasitic mode of nutrition.
Answer: Parasitic Nutrition: The parasitic nutrition is that nutrition in which an organism derives its food from the body of another living organism without killing it.
Organisms having parasitic mode of nutrition are Plasmodium and round-worms.
Question: How is the opening and closing of stomatal pore regulated in plants?
Answer: The opening and closing of stomatal pores is a function of guard cells. When water flows into guard cells, they swell up causing the stomatal pore to open. When the guard cells shrink, the pore closes.
Question: What are outside raw materials used by an organism?
Answer: Any organism uses organic molecules (i.e oxygen for respiration) as raw material. Auto- trophs use carbon dioxide, minerals, water and Heteroptrophs use food.
Question: What is the role of rings of cartilage present in the throat?
Answer: The rings of cartilage present in the throat ensure that the air passage does not collapse.
Question: On what factors does the direction of diffusion of carbon dioxide and oxygen depend in plants?
Answer: The direction of diffusion of carbon dioxide and oxygen in plants depends on the environmental conditions and the requirements of the plant.
Carbon dioxide elimination is the major exchange activity at night, whereas oxygen release is the main activity at day time.
Question: What are the differences between the transport of materials in xylem and phloem?
(1) Xylem tissue helps in the transport of water and minerals.
(2) Water is transported upwards from roots to all other plant parts.
(3) Transport in Xylem occurs with the help of simple physical forces such as transpiration 3 pull.
(1) Phloem tissue helps in the transport of food.
(2) Food is transported in both upward and downward directions.
(3) Transport (of food) in Phloem requires
energy in the form of ATP.
Question: What is the role of blood plasma?
Answer: Blood plasma transports food, carbon dioxide and nitrogenous wastes in dissolved form.
Question. What is Lymph? How is it different from blood?
Answer : Lymph is the light yellow fluid containing lymphocyte, which fights against infections.
|Blood is pumped throughout the body by heart.
|Lymph is moved along through the normal
function of the body.
|Blood transports oxygen throughout the body.
|Lymph removes waste from the system.
|Blood flows through the body in a circular
|The movement of lymph is in a single
|Blood contains red blood cells, white blood cells and
|Lymph is a light yellow and clear liquid.
|We can see blood with the naked eyes.
|Lymph cannot be seen with the naked eyes.
|The kidney purify the blood.
|Lymph is purified in the nodes itself.
Question. How are fats digested in our bodies? Where does this process take place?
Answer : Fats are first emulsified with the help of bile salts followed by their breakdown in fatty acids and glycerol due to the action of lipase. All these events take place in first part of small intestine-duodenum.
Question. Which is the universal source of energy in all cells?
Answer : ATP, Adenosine Tri Phosphate.
Question. If no apparent work is being done by an organism, why does it takes food?
Answer :To carry out life processes, growth, reproduction and for repair of worn out tissues.
Question. Differentiate between saprophytic nutrition and parasitic nutrition based on the type of food and manner of obtaining it.
|Saprophy t i c Nutrition
|Taking dead decay organic matter in the form of food is called saprophytic nutrition.
|Living on or inside other organisms and deriving their food from them without killing them.
|It shows extracellular digestion
|It has intracellular digestion.
|It does not depend on living host.
|It causes harm to the organism.
|E.g., fungi and bacteria.
|E.g., lice, tapeworm, leech.
Question. How do plants exchange gases?
Answer : Plants exchange gases through stomata. Large intercellular spaces ensure that each cell is in contact with air. Carbon dioxide and oxygen are exchanged here.
Question. List two factors which decide direction of diffusion of oxygen and carbon dioxide.
Answer : Environmental conditions and requirement of the plants decide direction of diffusion of oxygen and carbon dioxide.
Question. What are the strategies of plants to get rid of their wastes?
a. They throw away oxygen and water vapour through stomata.
b. Some wastes like gums, oil and resins may be stored in old xylem or wood in stem.
c. Some wastes may be stored in leaves and bark and shed off from time to time.
d. Roots can also throw some wastes.
Question. How is respiration different in plants and animals?
|Respiration in Plants
|Respiration in Animals
|It occurs through stomata, lenticels, root, etc.
|It occurs through lungs.
|It occurs through stomata, lenticels, root, etc.
|Animals release CO2
as waste into the atmosphere.
|Plants produce glucose and oxygen on their own-to carry out respiration.
|Animals get glucose and oxygen from outside to carry out respiration.
Question. Why do we feel pain or cramps in muscles after a vigorous exercise?
Answer : Actively metabolizing cells of an extremely active skeletal muscle, during heavy exercise, carry oxidation in the anaerobic condition inside the muscle cell, we feel pain after a vigorous exercise because of production of ATP by anaerobic respiration in leg muscles.
Question. List two ways in which plants can get rid of the wastes.
Answer : They can throw gases and excess water through stomata through diffusion. They can store wastes like gums and resins in old xylem tissue (wood).
Question. What is the role of acid and mucus in stomach?
Answer : It kills germs in food and provides acidic medium for the action of pepsin enzyme to digest the proteins in stomach.
Mucus protects the wall of stomach from the action of acid and pepsin.
Question. Which digestive secretion does not contain any enzyme but is important? Discuss.
Answer : Bile juice from liver. It contains bile salts which are necessary for emulsification of fats. It means breaking down large fat drops to very fine droplets so that lipase can act upon them easily.
Question. Differentiate between auricles and ventricles.
|Upper thin walled chambers.
|Lower thick walled chambers.
|Receive blood from veins.
|Receive blood from the auricles
|Push blood into the ventricles.
|Push blood into the arteries.
Question. Differentiate between Artery and Veins.
Answer : Arteries carry blood away from the heart (arteriole:
small arterial branch). They have thick and flexible walls to endure higher pressure of blood.
Veins transport blood toward the heart (venue: small vessel that carries blood from capillaries to veins). They have thinner wall but there are valves in them at regular distance to prevent back flow of blood especially when blood is returning back to heart from lower organs.
Question. Differentiate between respiration and breathing.
|It is a biochemical process.
|It is a physical process.
|O2 reacts with food and energy is released.
|Only exchange of gases
|Energy is released.
|No energy released.
|It occurs in cytoplasm and mitochondna.
|Occur in respiratory organs.
Question. What is the role of cartilaginous rings on trachea?
Answer : They prevent the collapsing of trachea when there is no air present in it.
Question. Name the type of blood vessels, which carry blood from organs to the heart.
Answer : Veins.
Question. Write a balanced equation for photosynthesis.
Question. What is the role of saliva in digestion of food?
Answer : Saliva lubricates and softens the food so that it can be easily chewed and swallowed. It contains enzyme amylase which breaks down starch to maltose.
Short Answer Type Questions:
Question: How do the guard cells regulate opening and closing of stomatal pores?
Answer: Stomata are tiny openings present on the underside of the leaf. The stomatal openings are surrounded two bean shaped cells. These are called guard cells. The main function of the guard cells is to control the opening and closing of stomata. When water enters the guard cell, it swells. This results in the opening of the guard cells. On the other hand, the shrinking of the guard cell results in the closing of the stomatal opening.
(a) Open stomatal pore (b) Closed stomatal pore
Question: Write two different ways in which glucose is oxidized to provide energy in human body.
Write the products formed in each case.
Answer: The first step is breakdown of the 6-carbon molecule glucose takes place in the cytoplasm of cells of all organism. In this step we obtain a 3 carbon molecule compound called pyruvate.
Subsequent ways in which this pyruvate may be broken down depends on the amount of oxygen available in the human body which are given below:
(1) Aerobic Respiration: Here, breakdown of pyruvate takes place in the presence
of oxygen in mitochondria to give rise to carbon dioxide, water and energy.
(2) Lack of Oxygen: This takes place in our muscles during vigorous exercise or activity.
When there is a lack of oxygen in our body, the pyruvate is converted into lactic acid, which is a 3 carbon molecule, and energy.
Question: (A) In the process of respiration, state the function of alveoli.
(B) Rate of breathing in aquatic organisms is much faster than that in terrestrial organisms. Give reasons.
(C) Complete the following pathway showing the breakdown of glucose:
Answer: (A) Function of Alveoli:
(i) Gaseous exchange takes place in alveoli in the lungs.
(ii) Alveoli provide a large surface area for the exchange of gases.
(B) Rate of breathing in aquatic organism is much faster than that in terrestrial organisms.
Terrestrial organisms breathe the oxygen in the atmosphere, but animals that live in water (aquatic organisms) use the oxygen dissolved in water. Since the amount of dissolved oxygen is very low as compared to amount of oxygen in the air (21%). So, the rate of breathing in aquatic organisms is much faster than that in terrestrial organisms
Question: Two green plants are kept separately in oxygen free containers, one in the dark and the other in continuous light. Which one will live longer? Give reasons.
Answer: The plant kept in continuous light will live longer because plants undergo photosynthesis in the presence of light. Due to this plants produce oxygen which it then uses for the process of respiration. This process will not take place in the plant that is kept in dark. As a result, it will not survive for a long time.
Question: “All plants give out oxygen during day and carbon dioxide during night.” Do you agree with this statement? Give reason.
Answer: Yes, the statement is correct. We know that respiration occurs throughout the day, whereas photosynthesis occurs only in the presence of sunlight. During the day time, as the rate of photosynthesis is more than the rate of respiration, CO2 generated during respiration is used up for photosynthesis, hence there is no CO2 released. Instead, oxygen release is the major event at this time and the net result is evolution of oxygen.
At night, there is no photosynthesis, so they give out carbon dioxide due to respiration.
Question: Complete the following flow chart as per the given instructions:
Answer: a—Hydrochloric acid
d—Functions of hydrochloric acid.
HCl makes the medium acidic as protein digesting enzymes pepsin acts in acidic medium.
It kills the harmful bacteria present in the stomach.
Functions of pepsin:
Pepsin breaks down proteins into peptones.
F—Functions of Mucus.
Mucus protects the inner lining of the stomach from the action of the acid under normal conditions.
Explanation: Gastric glands present in the wall of stomach secrete gastric j uice. Gastric juice
comprises these three secretions—HCl, pepsin and mucus. Gastric juice also contains gastric lipase which partially breaks down lipids.
Question: Explain the processes of aerobic respiration in mitochondria of a cell and anaerobic
respiration in yeast and muscle with the help of word equations.
Question: Answer the following:
(A) mention the adaptations of leaf for photosynthesis.
(B) Why does absorption of digested food occur mainly in small intestine?
Answer: (A) The adaptations of leaf for photosynthesis are as follows:
(1) Leaves have chlorophyll i.e. the main site for photosynthesis.
(2) The shape of the leaves enables to absorb maximum sunlight for photosynthesis.
(3) Leaves have stomata which help in gaseous exchange and transpiration.
Stomata help the leaves in taking in carbon dioxide and raw material for photosynthesis.
(4) The wide network in leaves helps in transport of water to the leaves and prepared food to the entire plant from the leaves.
(B) Maximum absorption of digested food occurs in small intestine due to following reasons
(1) Digestion process gets completed in small intestine.
(2) Inner lining of small intestine is provided with has millions of tiny, finger like projections called Villi. Each Villus has a network of fine blood capillaries close to the surface. The presence of Villi gives the inner walls of small intestine greater surface area which helps in rapid absorption of food.
(3) Wall of intestine is richly supplied with blood vessels through which the absorbed food is taken to each and every cell of the body.
Question: If a plant is releasing carbon dioxide and taking in oxygen during the day, does it mean that there is no photosynthesis occurring? Justify your answer.
Answer: If the plant shows evidence that it is releasing CO2 during the day and taking in oxygen, it does not mean that there is no photosynthesis taking place in the plant. Instead, it suggests that the plant is undergoing photosynthesis at a very low rate. In a normal scenario, the rate of respiration is higher during night while it is slower during the day. The CO2 produced during night time is utilized by the plant during the day to perform photosynthesis.
Question: Why do fishes die when taken out of water?
Answer: Fishes respire with the help of gills. Gills are richly supplied with blood capillaries and can readily absorb oxygen dissolved in water. Since fishes cannot absorb gaseous oxygen, they die soon after they are taken out of water.
Question: In each of the following situations what happens to the rate of photosynthesis?
(A) Cloudy days
(B) No rainfall in the area
(C) Good manuring in the area
(D) Stomata get blocked due to dust
Answer: (A) Cloudy days will cause the rate of photosynthesis to decrease due to the low availability of sunlight.
(B) No rainfall in the area will cause the rate of photosynthesis to decrease due to the low availability of water.
(C) Good manuring in the area will cause the rate of photosynthesis to increase due to the improved availability of minerals necessary for plant growth and development.
(D) The blockage of stomata due to dust will cause the rate of photosynthesis to decrease. This is because the CO2 required for photosynthesis enters the leaves through the stomata. If the stomata get blocked due to dust, less CO2, or no CO2 would enter the leaves or leaf and the rate of photosynthesis will drop.
Question: Answer the following:
(A) What would happen if all the green plants disappear from the earth?
(B) If a plant is releasing carbon dioxide and taking in oxygen during the day, does it
mean that there is no photosynthesis
occurring? justify your answer.
Answer: (A) Green plants are the sources of energy for all organisms. If all green plants disappear from the earth, all the herbivore will die due to starvation and so will the carnivores.
Since autotrophs are the only organisms that can fix the atmospheric carbon dioxide into organic compounds, these organisms occupies first trophic level in food chain and serve as source of food and energy for all other organisms of higher trophic levels (heterotrophs/consumers). Hence, in absence of these plants, whole functioning of whole ecosystem will come to a halt due to lack of food and energy source for consumers (herbivores, carnivores and omnivores)
(B) Respiration is the process of oxidation of food substances that release carbon dioxide; it takes place throughout the day.
Photosynthesis is the process of fixing the atmospheric carbon dioxide into organic compounds (carbohydrates) with release of oxygen gas as by product. Photosynthesis takes place during the day in presence of Sunlight only.
The CO2 released during respiration is absorbed by plants for photosynthesis during day causing net release of oxygen only. If a plant is releasing carbon dioxide and taking in oxygen during the day, it means that either rate of photosynthesis is too slow to counter balance the release of CO2 by respiration or photosynthesis is not taking place at all.
Question: Answer the following:
(A) What will happen to a plant if its xylem is removed?
(B) Given below is the diagram of a stomatal apparatus. Label the parts A, B, C and D.
Answer: (A) Xylem is a water-conducting tissue in plants.
It transports water from the roots to the different parts of the plant. If the xylem of the plant is removed, upward movement of water will stop leading to wilting of leaves and ultimately causes the death of a plant.
In the absence of water, the plant will not be able to prepare food and also perform other essential activities.
(B) A – Epidermal cell
B – Subsidiary cell
C – Guard cell
D – Stomatal aperture
Question: What is common for Cuscuta, ticks and leeches?
Answer: Cuscuta, ticks and leeches are parasites. They derive nutrition from plants or animals without killing them.
Question: Plants have low energy needs as compared to animals. Explain.
Answer: Plants are stationary and exhibit movement in terms of growth and development only, i.e.at cellular level. In addition, plants have dead schlerenchyma cells in many of their organs which in turn produce mechanical strength but are not involved in cellular process. Animals move from one place to another and need more energy compared to plants.
Question: Name the energy currency in living organisms. When and where is it produced?
Answer: ATP (Adenosine Triphosphate) is the energy currency in the living organisms. It is the energy currency for most cellular processes. The energy released during the process of respiration is used to make an ATP molecule from ADP and inorganic phosphate.
Endothermic processes in the cell then use this ATP to drive the reactions. When the terminal phosphate linkage in ATP is broken using water, energy equivalent to 30.5 kj / mol is released.
ATP can be used in the cells for the contraction of muscles, protein synthesis, conduction of nervous impulses and many other activities.
Question: What would happen if platelets were absent in the blood?
Answer: The blood has platelet cells which circulate around the body and help to clot the blood at the time of in??ury. In the absence of platelets, the process of clotting will be affected. Platelets play the important role of coagulation of blood.
No blood coagulation would take place in the bsence of platelets. This would be a dangerous situation in case of an in??ury, at it would result in excessive blood loss and can even prove lethal for the person.
Question: In photosynthesis, which structures are used up, which are produced and which are
necessary, but remain unchanged after the reaction?
Answer: Photosynthesis is defined as the process used by plants to convert light energy of the sun to chemical energy. While doing so, they use the water present in the roots of the plant to release oxygen that is used by other organisms. In this process, they use chlorophyll, a green pigment present in the leaf. But the amount of chlorophyll remains unchanged even after the process of photosynthesis is over.
Question: Why is transpiration important for plants?
Answer: Transpiration is important because:
(1) it helps in absorption and upward movement of water and minerals from roots to leaves.
(2) it prevents the plant parts from heating up.
Question: What are the end products formed during fermentation in yeast? under what conditions a similar process takes place in our body that leads to muscle cramps?
Answer: Fermentation of yeast or anaerobic respiration is defined as the kind of respiration that takes place in the absence of oxygen. The end products formed during this kind of respiration are: ATP, ethanol and carbon dioxide. When such a similar process takes place in our body, the muscles get tired easily. This happens because of the accumulation of lactic acid formed due to anaerobic respiration.
Question: Why and how does water enter continuously into the root xylem?
Answer: Cells of root are in close contact with soil and so actively take up ions. The ion-concentration, increases inside the root and hence osmotic pressure increases the movement of water from the soil into the root, which occurs continuously.
In the xylem tissue, vessels and tracheids of the roots, stems and leaves are interconnected to form a continuous system of water-conducting channels reaching all parts of the plant. At the roots, cells in contact with the soil actively take up ions. This creates a difference in the concentration of these ions between the root and the soil. Water, therefore, moves into the root from the soil to eliminate this difference.
This means that there is a steady movement of water into the root xylem, creating a column of water that is steadily pushed upwards.
Long Answer Type Questions:
Question: Give reasons:
(A) Ventricles have thicker muscular walls than atria.
(B) Transport system in plants is slow.
(C) Circulation of blood in aquatic vertebrates differs from that in terrestrial vertebrates.
(D) During the daytime, water and minerals travel faster through xylem as compared to the night.
(E) Veins have valves whereas arteries do not.
Answer: (A) Ventricles have thicker muscular walls than atria because they have to pump blood into various orgAnswer:
(B) Transport system in plants is slow because:
(1) Plants have low energy needs as
(2) Plant bodies have a large proportion of dead cells in many tissue.
(3) Plants do not move
(C) Aquatic vertebrates like fish have a two chambered heart (which consists of one atrium and one ventricle). The heart pumps deoxygenated to the gills and it gets oxygenated in the gills. The oxy genated blood from the gills is supplied to the body parts. Thus, blood goes only once through
the heart in the fish during one cycle of passage through the body.
But in terrestrial organisms, heart may be 3 or 4 chambered, blood gets oxygenated in the lungs and most of them have double circulation.
(D) During the daytime, water and minerals travel faster through xylem as compared to the night. The water column in the xylem tracheids and vessels moves upwards due to pull generated by transpiration. (loss of water in the form of vapours from living tissues of aerial parts of plants.) The water
is lost from the tiny pores called stomata present on the surface of leaves of plant.
Stomata are open during day time, so transpiration process is faster and water alongwith mineral moves faster through xylem during day time as compared to night time.
Explanation: The root hair absorb water and minerals from the soil by the process of diffusion. The water and minerals are passed from cell to cell by osmosis. Through the epidermis, root cortex, endodermis and reach the root xylem. The root xylem vessels carrying dissolved minerals enter the stem
xylem vessel and then to xylem vessels of leaves of the plants. Evaporation of water from the cells of leaves create a suction pull which pulls water from the xylem cells of roots. Evaporation is mor e during the day time.
(E) Veins have valves that ensure that the blood flows only in one direction. Values allow the blood to flow only towards the heart and prevent backflow but arteries do not have values.
Question: (A) Why is nutrition necessary for the human body?
(B) What causes movement of food inside the alimentary canal?
(C) Why is small intestine in herbivores longer than in carnivores?
(D) What will happen if mucus is not secreted by the gastric glands?
Answer: (A) Nutrition is the process of intake of nutrients and its utilization by an organism in various biological activities.
Importance of nutrition: All living organisms need nutrients (food):
(i) To build up their body molecules
(ii) To repair their worn out tissues.
(iii) To get energy for doing work.
(iv) To maintain various life processes.
(B) Rhythmic contraction and expansion movement of muscles of lining of various organs of alimentary canal pushes the partially or completely digested food forward in the track. This rhythmic contraction and relaxation movement is called peristaltic movement. This occurs throughout the gut.
(C) Small intestine in herbivores is longer than in carnivores as herbivores are grass eating animals. Longer, small intestine of herbivores help in digestion of cellulose which is present in the grass. Meat is digested easily so carnivores have shorter small intestine.
(D) Mucus is secreted by gastric glands along with hydrochloric acid and pepsin in the stomach. If mucus is not secreted by the gastric glands, hydrochloric acid would corrode the inner lining of stomach and may cause gastric ulcers.
Question: Explain the process of nutrition in Amoeba.
Answer: Amoeba follows the holozoic type nutrition. It is carried out as per the following steps:
Ingestion: Amoeba takes in food using temporary finger-like extensions of the cell surface which fuse over the food particle forming a food-vacuole. Engulfment of food particle by forming temporary pro??ections is called as ingestion.
Digestion: Inside the food vacuole, complex substances are broken down into simpler ones during digestion.
Absorption: The simple soluble food is absorbed by the cytoplasm of Amoeba from food vacuoles through the process of diffusion.
Assimilation: Amoeba cell obtains energy from the absorbed food through respiration. This energy is utilized by the amoeba for its growth and repair of the body.
Egestion: The remaining undigested material is moved to the surface of the cell and thrown out.