LIFE PROCESSES
CLASS 10
IMPORTANT QUESTIONS FOR BOARD EXAM
Question-1
Define nutrition? What are the different modes of nutrition?
Solution:
Nutrition is the process of intake, as well as utilization of nutrients by an organism. The different modes of nutrition are saprophytic nutrition, parasitic nutrition and holozoic nutrition.
Question-2
What is the mode of nutrition in fungi?
Solution:
Saprophytic nutrition is the mode of nutrition that is seen in fungi.
Question-3
How does amoeba engulf its food?
Solution:
Amoeba engulfs its food by extending pseudopodia. This process is known as Phagocytes.
Question-4
Name the parts of the digestive system of a grasshopper.
Solution:
The parts of digestive system of a grasshopper are pharynx, salivary glands, hepatic caeca, Malpighian tubules, ileum, colon, rectum and anus.
Question-5
What are the functions of the liver and the pancreas?
Solution:
The liver secretes bile, which contains bile pigments and bile salts. The bile secreted by the liver cells is normally stored in the gall bladder, until needed in the duodenum. Pancreas lie parallel to and beneath the stomach. It is a large gland, which secretes digestive enzymes as well as the hormones, insulin and glucagons. Both bile and pancreatic juice enter duodenum through a common duct. Bile emulsifies fat present in the food. Pancreatic juice contains trypsin, for digesting proteins and pancreatic amylase for the breakdown of starch.
Question-4
How is respiration different from breathing?
Solution:
Respiration is a complex process, which includes breathing, the mechanism of exchange of gases,oxygen and carbon dioxide and oxidation of digested food occurring in the cells in order to release energy. The main outcome of respiration is the release of energy through oxidation of simple food molecules such as glucose.
Question-5
In which kind of respiration is more energy released?
Solution:
In aerobic respiration more energy is released.
Question-6
Which part of the roots is involved in exchange of respiratory gases?
Solution:
Root hair is the part of the root which is involved in exchange of respiratory gases.
Question-7
Give two points of differences between respiration in plants and respiration in animals.
Solution:
The respiration in plants differ from respiration in animals in two respects, they are
(i) There is minimal transport of gases from one part of the plant to another, unlike the animals.
(ii) Plant respiration occurs at a much slower rate than animal respiration.
Question-8
Name the respiratory organs of
(i) fish
(ii) mosquito
(iii) earthworm
(iv) dog
Solution:
The respiratory organs of
(i) fish – gills
(ii) mosquito – tracheoles
(iii) earthworm – skin
(iv) dog – lungs.
Short Answer Questions (2 Marks)
1. What is common for cuscuta, ticks and leeches?
Ans: Cuscuta, ticks, and leeches all feed in a parasitic manner, harming their hosts in the process.
2. What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
Ans: Terrestrial organisms have evolved to be more efficient at absorbing oxygen from the air than watery organisms. –
Increased respiratory surface area.
Very fine and delicate surface for easy exchange of oxygen and carbon – dioxide.
Placement of respiratory surface within the body for protection.
The mechanism for transporting air into and out of the respiratory surface, which absorbs oxygen.
3. Name the substrates for the following enzymes.
trypsin
amylase
pepsin
lipase
Ans: The substrates for the following enzymes are as shown below
a) Protein
b) Starch
c) Protein
d) Lipids
4. What is villi? What are its functions?
Ans: Villi are projections in the small intestine's inner lining that resemble fingers. They enhance the surface area available for digested meal absorption in the small intestine.
5. What type of respiration takes place in human muscles during vigorous exercise and why?
Ans: Anaerobic respiration occurs in human muscles during severe exercise. During exercise, our energy requirement increases, so our striated muscles start respiring anaerobically in the lack of oxygen and produce ATP molecules.
6. How is opening and closing of stomata regulated?
Ans: Guard cells control the closure and opening of the stomata. The stomata open when the guard cells enlarge or become turgid owing to water ingress. Because of the loss of water, the guard cells shrink and the stomata close.
7. State two vital functions of the kidney.
Ans: Function of the kidney are –
It keeps the body's water balance in check.
It regulates calcium levels in the blood to keep bones healthy
8. What is the role of the glomerulus in the kidney?
Ans: Glomerulus, like Bowman's Capsule, is a collection of capillaries found in the cup. It gets blood from the renal artery, which is responsible for transporting excretory wastes from the body to the kidney. It removes from the liver water, salts, glucose, urea, nitrogen-containing protein end products, and yellow bile components.
9. Why is it essential to match the blood groups of donors and receiver person before arranging transfusion of blood?
Ans: Blood RBCs carry both antigen and antibodies. If the blood is not matched before transfusion, the recipient's blood produces antibodies against the donor blood and destroys blood cells, resulting in a blood shortage and death.
10. Why is it necessary to separate oxygenated & deoxygenated blood in mammals & birds?
Ans: The separation of oxygenated and deoxygenated blood allows the organism to receive adequate oxygen. This mechanism is beneficial to creatures who demand a lot of energy. Mammals and birds use oxygen to obtain energy in order to maintain a consistent body temperature.
11. Why are the walls of the trachea supported by cartilaginous rings?
Ans: The trachea is held together by cartilaginous rings that keep it from collapsing even when there isn't much air in it.
12. What are the raw materials for photosynthesis?
Ans: Raw materials for photosynthesis are –
Carbon – dioxide
Water
Chlorophyll and Sunlight
13. What is the role of the diaphragm during inhalation and exhalation?
Ans: During inhalation and exhalation, the diaphragm changes form, increasing and decreasing the capacity of the thoracic cavity. This causes air to enter and exit the lungs.
14. What is the advantage of four chambers of heart?
Ans: A septum separates the right and left halves of the heart, preventing oxygenated and deoxygenated blood from mingling. This satisfies their constant need for energy to keep their body temperature steady. Their energy requirements are substantial, which are met effectively due to the non-mixing of oxygenated and deoxygenated blood.
15. diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?
Ans: As all cells in multicellular animals are not in direct contact with the environment, simple diffusion is insufficient to supply the needs of all body cells.
16. What criteria do we use to decide whether something is alive?
Ans: To be considered alive, all living organisms must have movement at the molecular level, as well as respiration and other life processes such as nutrition, respiration, transportation, and excretion.
17.What is the function of digestive enzymes?
Ans: Enzymes break down food's different complicated components into simple, soluble components that can be easily absorbed.
18. How are the lungs designed in human beings to maximize the area for exchange of gases?
Ans: Bronchioles end in alveoli, which are balloon-like structures in the lungs. Alveoli have a network of blood capillaries that increase the surface area available for gas exchange.
19. What is the role of saliva in the digestion of food?
Ans: Salivary amylase is an enzyme found in the mouth that breaks down starch, a complicated molecule, into glucose.
20. While eating you are advised not to talk. Why are you advised to do so?
Ans: We are urged to do so because food particles may enter the windpipe when eating, causing choking.
21. We say that movement is a characteristic of living organisms but we always don’t see visible movements in plants. Comment.
Ans: Plants do not always show obvious movement. It doesn't necessarily imply that they aren't living. In their bodies, molecular movements take place.
22. If a person is working on a treadmill in a gymnasium, will it affect his rate of breathing? How?
Ans: Yes, it will have an impact on his breathing rate. To satisfy the increased demand for energy, the rate of breathing will increase in order to supply more oxygen.
Long Answer Questions (3 Marks)
1. What are the functions of lymph in our body?
Ans: Functions of lymph are-
a) It removes tissue fluid from the interstitial region and restores it to the bloodstream.
b) Through tissue fluid, it gathers carbon dioxide, waste products, and metabolites from tissues.
c) Lymph contains lymphocytes (WBCs), which aid in the body's immunity and fight against invading invaders.
2. How is haemoglobin associated with respiration explained?
Ans: The respiratory pigment haemoglobin is responsible for transporting oxygen and carbon dioxide. Haemoglobin is a crimson pigment with a strong oxygen affinity. Oxyhemoglobin transports oxygen from the lungs to the cells of the body. Carbon dioxide is carried to the lungs by carbamino – haemoglobin from the bodily cells.
3. What are the modes of excretion in plants?
Ans: Modes of excretion in plants are –
The plants get rid of excess water by transpiration.
Plants' only primary gas excretory product is oxygen. Plants emit it into the environment by diffusion. Organic wastes of plants are stored within dead permanent tissues such as wood or within leaves or bark which are periodically removed.
The plants also excrete some waste substances into the soil around them.
Plant waste products are accumulated in cellular vacuoles in large quantities.
4. Give an experiment to prove the essentiality of light for photosynthesis.
Ans: An experiment to prove the essentiality of light for photosynthesis is as shown below:
a) Destarched the plant by leaving it in dart for 48 – 72 hours.
b) Now place strips of black paper or metal foil over destarched leaves and expose them to light for several hours.
5. What is “translocation”? Why it is essential for plants.
Ans: The term "translocation" refers to the movement of organic solutes within plants. It is required since all cells require sustenance to perform their essential tasks. It affects the storage organs of roots, fruits, seeds, and developing organs in both upward and downward directions.
6. How respiration takes place in plants?
Ans: There are three modes for the exchange of gases in plants –
a) Some little plants can exchange gaseous matter by simply diffusing it throughout their entire surface.
b) Stomata on the leaves and green stems of large flowering plants exchange gases.
c) Exchange occurs in woody stems through fractures in the bark or lenticels.
7. How is transpiration pull responsible for upward movement of water?
Ans: Transpiration is the process through which leaves lose water in the form of water vapours through stomata. Continuous transpiration causes a suction in the xylem elements' water column, which reaches the roots. This is known as transpiration pull. The water column of the plant is drawn up from the bottom to the top due to transpiration.
8. Discuss the major steps involved in the process of nutrition in human beings.
Ans: Major steps involved in human nutrition are –
a) Ingestion – Food is taken in through the mouth. Humans have a holozoic feeding mode. Solid particles are swallowed by them.
b) Digestion – In the alimentary canal, mechanical and chemical processes are used to break down complex dietary materials into simpler ones.
c) Absorption – The little finger-like projections, or villi, of the small intestine absorb digested food.
d) Assimilation – Food is absorbed and transported to all cells via blood, where it is used for energy, growth, and development.
e) Excretion – Food from the small intestine passes through to the big intestine, where it is ejected out by Anus.
9. Discuss the mode of nutrition in amoeba.
Ans: The steps of Nutrition in amoeba are–
a) Formation of pseudopodia – When an amoeba comes into contact with a food particle, it creates pseudopodia that encase the food particle.
b) Ingestion – Ingestion occurs when the terminals of pseudopodia merge with one other, forming a food vacuole with a variable amount of food particles and water.
c) Digestion – The vacuoles are encircled by lysosomes, which fuse with the vacuole and consume the food particles inside.
d) Exocytosis – The food vacuole passes the soluble products of digestion into the appropriate cytoplasm. Exocytosis is the process through which the remaining undigested items are passed out of the body.
10. With the help of a labelled diagram, discuss the structure of the cross–section of leaf.
Ans: Leaf has two parts:
Epidermis – The epidermis is the cell's outermost layer. Stomata are tiny pores that connect cells in the lower epidermis.
Mesophyll – Mesophyll refers to the chloroplast-containing parenchyma cells. Palisade and spongy parenchyma are the two types.
11. What do you mean by ‘lymph’? Mention its function.
Ans: Lymph- Tissue fluid, or lymph, is the fluid that fills the gaps between the cells in the tissues.
Functions of lymph:
It returns tissue fluid from the interstitial spaces into the blood.
Lacteals, which are lymph capillaries found in intestinal villi, aid in fat absorption.
Through tissue fluid, it gathers carbon dioxide, waste products, and metabolites from tissues.
12. How are lungs designed in human beings to maximize the area of exchange of gases?
Ans: Lungs have evolved various characteristics to allow for effective gas exchange. The modifications are as follows:
Increased surface area
Very fine and delicate surface for easy exchange of oxygen and carbon dioxide
The mechanism for transporting air into and out of the respiratory surface, which absorbs oxygen.
13. Dark reactions of photosynthesis do not need light. Do plants undergo dark reactions at night?
Ans: The term "dark reaction" does not refer to a reaction that occurs in the absence of light, such as at night. In fact, these reactions are independent of light energy and occur at the same time as light reactions.
14. Why and how does water enter continuously into the root xylem of plants?
Ans: Water and minerals are transported to the plant body via xylem. Root hairs are hairs that grow on a plant's roots. The root hairs come into close touch with the water film that forms between soil particles. Diffusion allows water and minerals to penetrate the root hair. The water and minerals are taken by the root hair from the soil move via the epidermis, root cortex, endodermis, and root xylem by osmosis from cell to cell. The plant's xylem vessels in the root are connected to the xylem vessels in the stem. As a result, dissolved mineral-containing water passes through the root xylem vessels and into the stem xylem vessels. The stem's xylem vessels branch out into the plant's leaves. As a result, the water and minerals supplied by the xylem vessels in the stem reach the leaves via the branched xylem vessels that enter each area of the leaf from the petiole. As a result, water and minerals from the earth reach the plants' leaves via the root and stem. The suction created by the evaporation of water molecules from the cells of a leaf pulls water from the xylem cells of roots. Transpiration is the loss of water from the aerial portions of plants in the form of vapour.
15. How are the alveoli designed to maximize the exchange of gases?
Ans: The nostril, larynx, nasal chamber, pharynx, trachea, epiglottis, alveoli, bronchioles, bronchi, and lungs make up the human respiratory tract. Through millions of small sacs known as alveoli, oxygen is exchanged for carbon dioxide waste within the lungs. Inhaled oxygen diffuses into the lungs' capillaries, binds to haemoglobin, and is pumped into the bloodstream. Exhalation allows the carbon dioxide from the blood to diffuse through the alveoli and be evacuated. To promote the exchange of gases between blood and the air-filled alveoli, the alveoli have thin walls and are richly supplied with a network of blood veins. They have a balloon-like shape to maximise gas exchange surface area. The alveolar walls are folded and have a significant surface area. It has a large network of blood arteries that serve as a surface for gas exchange.
16. What would be the consequence of a deficiency of hemoglobin in our bodies?
Ans: Haemoglobin is a pigment found in red blood cells. It has a strong preference for oxygen. It transports oxygen from the lungs to other tissues that are oxygen-deficient. The presence of less haemoglobin reduces the oxygen supply to tissues. A person with low haemoglobin levels will become exhausted quickly and seem pale.
17.Describe an experiment to prove that carbon – dioxide is essential for the process of photosynthesis.
Ans: Experiment showing that carbon dioxide is essential for photosynthesis.
Take a potted plant with elongated leaves
Take an empty bottle and put a little amount of potassium hydroxide (
) in it. Now cut the cork of the bottle into two parts and place it on one of the leaves of the potted plant in between the two parts of the cork.
Now put the bottle in the presence of sunlight for 72 – 96 hours.
Now test the leaf for the presence of starch.
18. Describe the structure and functioning of nephron.
Ans: Each nephron is a collection of blood capillaries with very thin walls. Each glomerulus (capillary cluster) in the kidney is linked to the cup-shaped Bowman's capsule, which collects the filtered urine. The blood is filtered by the nephron to eliminate nitrogenous waste.
They also absorb some vital substances from the filtrate, including glucose, amino acids, minerals, and a significant amount of water.
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