Lakhmir Singh & Manjit Kaur Solutions: Life Processes - 3 | Science Class 10 PDF Download

Page No - 46 

Question 1:
Do all cells use oxygen to produce energy ?
Solution :
No.

Question 2:
Name one substance which is produced in anaerobic respiration by an organism but not in aerobic respiration.
Solution :
Ethanol.

Question 3:
Name one organism which can live without oxygen.
Solution :
Yeast can live without oxygen.

Question 4:
In which type of respiration, aerobic or anaerobic, more energy is released ?
Solution :
Aerobic respiration.

Question 5:
Name the substance whose build up in the muscles during vigorous physical exercise may cause cramps.
Solution :
Lactic acid.

Question 6:
Which part of roots is involved in the exchange of respiratory gases ?
Solution :
Root hairs.

Question 7:
Name the process by which plant parts like roots, stems, and leaves get oxygen required for respiration.
Solution :
Diffusion.

Question 8:
Name the pores in a leaf through which respiratory exchange of gases takes place.
Solution :
Stomata.

Question 9:
Name the areas in a woody stem through which respiratory exchange of gases takes place.
Solution :
Lenticels.

Question 10:
What is the name of the extensions of the epidermal cells of a root which help in respiration ?
Solution :
Root hair.

Question 11:
Out of photosynthesis and respiration in plants, which process occurs :
(a) all the time ?
(b) only at daytime ?
Solution :
(a) Respiration.
(b) Photosynthesis.

Question 12:
Name the organs of breathing in fish.
Solution :
Gills.

Question 13:
Name an animal which absorbs oxygen through its moist skin.
Solution :
Earthworm.

Question 14:
Name an animal which depends on simple diffusion of gases for breathing.
Solution :
Amoeba.

Question 15:
Name two animals which breathe through gills.
Solution :
Prawns and mussels.

Question 16:
The trachea divides into two tubes at its lower end. What is the name of these tubes ?
Solution :
Bronchi.

Question 17:
Where does the blood absorb oxygen in the human body ?
Solution :
Alveoli.

Question 18:
Name the red pigment which carries oxygen in blood.
Solution :
Haemoglobin.

Question 19:
Which gases are exchanged in your lungs ?
Solution :
Oxygen and carbon dioxide.

Question 20:
Where in the lungs does gas exchange take place ?
Solution :
Alveoli.

Question 21:
What is the name of tiny air-sacs at the end of smallest bronchioles in the lungs ?
Solution :
Alveoli.

Question 22:
What is the other name of wind-pipe ?
Solution :
Trachea.

Question 23:
What organs are attached to the two bronchi ?
Solution :
Lungs.

Question 24:
In the lungs :
(a) what substance is taken into the body ?
(b) what substance is removed from the body ?
Solution :
(a) Oxygen.
(b) Carbon dioxide.

Question 25:
State whether the following statements are true or false :
(a) During respiration, the plants take C02 and release 02.
(b) Energy can be produced in cells without oxygen.
(c) Fish and earthworm exchange gases during respiration in the same way.
Solution :
(a) False.
(b) True.
(c) False.

Question 26:
Fill in the following blanks with suitable words :
(a) The organs of respiration in man are the…………..
(b) The actual exchange of gases takes place in the………… of the lungs.
(c) ………………in the lungs provide a very large surface area for gaseous exchange.
(d) Yeast undergoes……….. respiration whereas Amoeba undergoes………….. respiration.
(e) Gills are the breathing organs in…………..
Solution :
(a) Lungs.
(b) Alveoli.
(c) Alveoli.
(d) Anaerobic, aerobic.
(e) Fish.

Question 27:
Explain why, a land plant may die if its roots remain water logged for a long time.
Solution :
A land plant may die if its roots remain water logged for a long time because too much water expels all the air from in-between the soil particles. Due to this, oxygen is not available to the roots for aerobic respiration. Under these conditions the roots will respire anaerobically producing alcohol which may kill the plant.

Question 28:
What are the differences between aerobic and anaerobic respiration ? Name some organisms that use anaerobic mode of respiration.
Solution :
(a)
Aerobic respiration
(i) Aerobic respiration takes place in the presence of oxygen.
(ii) Complete breakdown of food occurs in aerobic respiration.
(iii) The end products in aerobic respiratin are carbon dioxide and water.
(iv) Aerobic respiration produces a considerable amount of energy.
Anaerobic respiration
(i) Anaerobic respiration takes place in the absence of oxygen.
(ii) Partial break down of food occurs in anaerobic respiration.
(iii) The end products in anaerobic respiration are ethanol and carbon dioxide (in yeast) and lactic and (in animal muscles).
(iv) Much less energy is produced in anaerobic respiration.
(b) Yeast and some bacteria.

Question 29:
Name the final product/products obtained in the anaerobic respiration, if it takes place :
(a) in a plant (like yeast).
(b) in an animal tissue (like muscles).
Solution :
(a) Ethanol and carbon dioxide.(b) Lactic acid.

Question 30:
What type of respiration takes place in human muscles during vigorous physical exercise ? Give reason for your answer.
Solution :
Anaerobic respiration takes place in human muscles during vigorous physical exercise because oxygen gets used up faster in the muscle cells than can be supplied by the blood.

Question 31:
Name the type of respiration in which the end products are :
(a) C2H,OH and C02
(b) C02 and H20
(c) Lactic acid
Give one example of each case where such a respiration can occur.
Solution :
(a) Anaerobic respiration in yeast.
(b) Aerobic respiration in humans.
(c) Anaerobic respiration in muscle tissue of animals.

Question 32:
Define breathing. State the differences between breathing and respiration.
Solution :
The mechanism by which an organism obtains oxygen from the air and releases carbon dioxide is called breathing.Difference between breathing and respiration:-
Breathing
(i) Breathing is a simple process.
(ii) Breathing involves taking in oxygen from the air and releasing carbon dioxide into the air.
(iii) Breathing is a physical process.
Respiration
(i) Respiration is a complex process.
(ii) Respiration includes breathing as well as the oxidation of food in the cells of the organism to release energy.
(iii) Respiration is a bio-chemical process.

Question 33:
What are the different ways in which glucose is oxidised to provide energy in various organisms ? Give one example of each.
Solution :
There are two ways in which glucose is oxidized to provide energy in various organisms:
(i) Anaerobic respiration ? The respiration which takes place without oxygen is called anaerobic respiration.Example: Yeast and some bacteria break down glucose into ethanol and carbon dioxide.
(ii) Aerobic respiration ? The respiration which uses oxygen is called aerobic respiration.Example: Plants and animals break down glucose completely into carbon dioxide and water to release energy.

Page No - 48

Question 34:
Explain why, when air is taken in and let out during breathing, the lungs always contain a residual volume of air.
Solution :
During the breathing cycle, when air is taken in and let out, the lungs always contain a certain residual volume of air so that there is sufficient time ‘for the oxygen absorbed’ into the blood and ‘for the carbon dioxide to be released’ from the blood.

Question 35:
Explain why, it is dangerous to inhale air containing carbon monoxide.
Solution :
It is dangerous to inhale air containing carbon monoxide as it binds very strongly with haemoglobin in the blood and prevents it from carrying oxygen to the brain and other parts of the body. Due to lack of oxygen, the person cannot breathe properly and may become unconscious or may even die.

Question 36:
Describe the process of respiration in State whether it is anaerobic respiration or aerobic respiration.
Solution :
(a) Respiration in amoeba: Amoeba depends on simple diffusion of gases for breathing. The diffusion of gases takes place through the thin cell membrane of amoeba. Amoeba lives in water which contains dissolved oxygen. The oxygen from water diffuses into the body of amoeba through its cell membrane. The oxygen spreads quickly into the whole body and is used for respiration inside the amoeba cell. The process of respiration produces carbon dioxide which diffuses out through its cell membrane into the surrounding water.

Diagram to show the process of breathing

(gaseous exchange ) in Amoeba

(b) It is aerobic respiration.

Question 37:
State the three common features of all the respiratory organs like skin, gills and lungs.
Solution :
The common features of all respiratory organs ? skin, gills and lungs are: (i) All the respiratory organs have a large surface area to get enough oxygen.(ii) All the respiratory organs have thin walls for easy diffusion and exchange of respiratory gases.(iii) All the respiratory organs like skin, gills and lungs have a rich blood supply for transporting respiratory gases.

Question 38:
Describe the process of respiration in fish.
Solution :
Respiration and fish: The fish has special organ of breathing called gills on both the sides of its head. The gills are covered by gill covers. The fish lives in water which contains dissolved oxygen. The fish breathes by taking in water through its mouth and sending it over the gills. When water passes over the gills, the gills extract dissolved oxygen from the water. The extracted oxygen is absorbed by the blood and carried to all the parts of the fish. The carbon dioxide produced by respiration is brought back by the blood into the gills for expelling into the surrounding water.

Question 39:
What would be the consequences of deficiency of haemoglobin in our bodies ?
Solution :
The deficiency of haemoglobin in the blood of a person reduces the oxygen carrying capacity of blood resulting in breathing problems, tiredness and lack of energy.

Question 40:
Describe the process of respiration in the following parts of a plant :
(a) Root (b) Stem (c) Leaves
Solution :
(a) Respiration in roots: The roots of a plant take the oxygen required for respiration from the air present in-between the soil particles by the process of diffusion. The roots have extensions of epidermal cells of a root called root hair which are in contact with the air in the soil. Oxygen diffuses from root hairs and reaches all the other cells of the root for respiration. Carbon dioxide gas produced in the cells of the root during respiration moves out through the root hairs by the process of diffusion. Thus, the respiration in roots occurs by diffusion of respiratory gases through the root hairs.
(b) Respiration in stems: The stems of herbaceous plants takes place through stomata. The oxygen from the air diffuses into the stem of a herbaceous plant through stomata and reaches all the cells for respiration. The carbon dioxide produced diffuses out through stomata. In woody stems, the bark has lenticels for the exchange of gases.
(c) Respiration in leaves: The leaves of a plant has tiny pores called stomata through which the exchange of respiratory gases takes place by diffusion. Oxygen from air diffuses into a leaf through stomata and reaches all the cells, where it is used for respiration and the carbon dioxide produced diffuses out from the leaf into the air through stomata.

Question 41:
(a) What is meant by aquatic animals and terrestrial animals ?
(b) From where do the aquatic animals and terrestrial animals obtain oxygen for breathing and respiration ?
Solution :
(a) Aquatic animals are the animals which live in water and the terrestrial animals are the animals which live on land.
(b) The aquatic animals use the oxygen dissolved in water to carry out respiration. The terrestrial animals obtain oxygen from air.

Question 42:
Why do fishes die when taken out of water ?
Solution :
Fishes die when taken out of water because they do not have lungs to utilize the oxygen of air for breathing and respiration. They have gills which can extract only dissolved oxygen from water.

Question 43:
Why is the rate of breathing in aquatic organisms much faster than in terrestrial organisms ?
Solution :
The rate of breathing in aquatic animals is much faster than terrestrial animals because the amount of oxygen dissolved in water is low as compared to the amount of oxygen dissolved in air.

Question 44:
Name the energy currency in the living organisms. When and where is it produced ?
Solution :
The energy currency of the cell is ‘ATP’. It is produced in cytoplasm in lower organisms which respire anaerobically. In higher organisms, ‘ATP’ is produced in mitochondria when they respire aerobically.

Question 45:
Explain why, plants have low energy needs as compared to animals.
Solution :
Plants do not move. In a large plant body there are many dead cells like sclerenchyma as a result it requires less energy as compared to animals.

Question 46:
Explain how, it would benefit deep sea divers if humans also had gills.
Solution :
If humans also had gills then the deep sea divers could remain under sea water even without carrying oxygen cylinders for breathing as they would be able to extract the dissolved oxygen from water for breathing purpose just like a fish does.

Question 47:
(a) What is the function of the respiratory system ?
(b) What are the major organs of respiratory system in man (or humans) ?
(c) Draw a labelled diagram of the human respiratory system.
Solution :
(a) The function of respiratory system is to breathe in oxygen for respiration (producing energy from food), and to breathe out carbon dioxide produced by respiration.
(b) The major organs of respiratory system in human beings are:
(i) Nose
(ii) Nasal Passage
(iii) Trachea
(iv) Bronchi
(v) Lungs and
(vi) diaphragm.

Question 48:
(a) Explain how, the air we breathe in gets cleaned while passing through the nasal passage.
(b) Why do the walls of trachea not collapse when there is less air in it ?
(c) How are oxygen and carbon dioxide exchanged in our body during respiration ?
(d) How are lungs designed in human beings to maximise the exchange of gases ?
Solution :
(a) When air passes through the nasal passage, the dust particles and other impurities present in it are trapped by nasal hair and mucus so that clean air goes into the lungs.
(b) Trachea does not collapse even when there is no air in it because it is supported by rings of soft bones called cartilage.
(c) During the process of ‘breathing in’ the air sacs or alveoli of the lungs get filled with air containing oxygen. The alveoli are surrounded by capillaries carrying blood so the oxygen of air diffuses from the alveoli walls into the blood from where it is carried to all the parts of the body.As the blood passes through the tissues of the body, the oxygen present in it diffuses into the cells. This oxygen combines with the digested food to release energy. Carbon dioxide gas is produced as a waste product during respiration in the cells of the body tissues which diffuses into the blood. Blood carries the carbon dioxide back to the lungs where it diffuses into the alveoli.
(d) The human lungs have been designed to maximise the exchange of gases as there are millions of alveoli in the lungs which provides a large surface area for the exchange of gases.

Question 49:
(a) Give the main points of difference between respiration in plants and respiration in animals.
(b) Describe the exchange of gases which takes place in the leaves of a plant (a) during daytime, and (b) at night.
(c) Which contains more carbon dixoide : exhaled air or inhaled air ? Why ?
Solution :
Respiration in plants
(i) All the parts of the plants perform respiration individually.
(ii) During respiration in plants there is a little transport of respiratory gases from one part of the plant to the other.
(iii) The respiration in plants occurs at a slow rate.
Respiration in Animals
(i) An animal perfomrs respiration as a single unit.
(ii) Respiratory gases are usually transported over long distances inside an animal during respiration.
(iii) The respiration in animals occurs at a much faster rate.
(b)
(i) During daytime when photosynthesis occurs, oxygen is produced. The leaves use some of this oxygen for respiration and the rest of oxygen diffuses out into the air. Carbon dioxide produced by respiration is all used up in photosynthesis by leaves during the daytime. Even more carbon dioxide is taken in from air. Thus, the net gas exchange in leaves during daytime is: Oxygen diffuses out; Carbon dioxide diffuses in.
(ii) At night time, when no photosynthesis occurs and hence no oxygen is produced, oxygen from air diffuses in leaves to carry out respiration. Carbon dioxide produced by respiration diffuses out into air. So, the net gas exchange in leaves at night is: Oxygen diffuses in; Carbon dioxide diffuses out. (c) Exhaled air contains more carbon dioxide because during the respiration process when oxygen breaks down glucose, then a lot of carbon dioxide is produced hence the exhaled air has a higher proportion of the same.

Question 50:
(a) “Respiration is a vital function of the body”. Justify this statement.
(b) What is the main difference between aerobic respiration and anaerobic respiration ? Give one example of each.
(c) What type of repiration takes place (i) in yeast, and (ii) in humans ?
Solution :
(a) Respiration is a vital function of the body as it provides energy for carrying out all the life processes which are necessary to keep the organism alive.
(b)
Aerobic respiration
(i) Aerobic respiration takes place in the presence of oxygen.
(ii) Complete breakdown of food occurs in aerobic respiration.
(iii) The end products in aerobic respiration are carbon dioxide and water.
(iv) Aerobic respiration produces a considerable amount of energy.
Example: Human Beings.
Anaerobic respiration
(i) Anaerobic respiration takes place in the absence of oxygen.
(ii) Partial breakdown of food occurs in anaerobic respiration.
(iii) The end products in anaerobic respiration are ethanol and carbon dioxide (in yeast) and lactic acid (in animal muscles).
(iv) Much less energy is produced in anaerobic respiration. Example: Yeast.
(c)
(i) Anaerobic respiration.
(ii) Aerobic respiration.

Question 51:
(a) Why is diffusion insufficient to meet the oxygen requirements of large multicellular organisms like humans ?
(b) What type of arrangement exists in the bodies of large animals to meet their oxygen requirements adequately ?
(c) What advantage a terrestrial animal has over an aquatic animal with regard to obtaining oxygen for respiration ?
Solution :
(a) Diffusion is insufficient to meet the oxygen requirements of large multicellular organisms like humans because the volume of human body is so big that the oxygen cannot diffuse into all the cells of the human body quickly and oxygen will have to travel large distances to reach each and every cell of the body.
(b) Large organisms contain a respiratory pigment called haemoglobin which carries the oxygen from the lungs to all the body cells very efficiently.
(c) A terrestrial animal has an advantage over an aquatic animal in regard to obtaining oxygen for respiration that it is surrounded by an oxygen rich atmosphere from where it can take any amount of oxygen.

Page No - 72

Question 1:
What is the name of tissues which transport :
(a) food in a plant ?
(b) water and minerals in a plant ?
Solution :
(a) Phloem.
(b) Xylem.

Question 2:
What substance/substances are transported in plants by :
(a) xylem vessels and tracheids ?
(b) sieve tubes (or phloem) ?
Solution :
(a) Water.
(b) Food.

Question 3:
Which organ acts as a pump in the circulatory system ?
Solution :
Heart.

Question 4:
Veins and arteries carry blood. Which of these carry blood :
(a) away from the heart ?
(b) back to the heart ?
Solution :
(a) Arteries.
(b) Veins.

Question 5:
Where does blood absorb oxygen ?
Solution :
Capillaries.

Question 6:
What stops blood from flowing backwards through the heart ?
Solution :
Valves stop the blood from flowing backward through the heart.

Question 7:
Name (i) largest artery, and (ii) largest vein, in our body.
Solution :
(i) The largest artery in the human body is ‘Aorta’.
(ii) The largest vein in the human body is ‘Vena Cava’.

Question 8:
What gaseous waste products are excreted by plants ?
Solution :
Carbon dioxide, water vapour and oxygen.

Question 9:
Where is the dirty blood in our body filtered ?
Solution :
Glomerulus present in kidneys.

Question 10:
Name the procedure used in the working of artificial kidney.
Solution :
Dialysis.

Question 11:
From the following terms, choose one term which includes the other four :
Plasma, Platelets, Blood, RBC, WBC
Solution :
Blood.

Question 12:
What are the components of the transport system in highly organised plants ?
Solution :
Xylem and phloem.

Question 13:
Out of xylem and phloem, which one carries materials :
(a) upwards as well as downwards ?
(b) only upwards ?
Solution :
(a) Phloem.(b) Xylem.

Question 14:
Name two liquids which help in the transport of substances in the human body.
Solution :
Blood and lymph.

Question 15:
What is the other name of main vein ?
Solution :
Vena Cava.

Question 16:
Name the conducting tissue of plants which is made of sieve tubes alongwith companion cells.
Solution :
Phloem.

Question 17:
Name the conducting tissue in plants which is made of (a) living cells, and (b) dead cells.
Solution :
(a) Phloem.
(b) Xylem.

Question 18:
State the term used for the transport of food from leaves to other parts of plant.
Solution :
Translocation.

Question 19:
Which process in a plant is accomplished by utilising energy from ATP : transport of water and minerals or transport of food ?
Solution :
Transport of food.

Question 20:
Name the two types of transport systems in the human beings.
Solution :
Blood circulatory system and lymphatic system.

Question 21:
Name a waste gas released by the plants (a) only during the day time, and (b) only during the night time.
Solution :
(a) Oxygen.
(b) Carbon dioxide.

Question 22:
Name one animal having single circulation of blood and another having double circulation.
Solution :
A fish has single circulation of blood and a frog has double circulation of blood.

Question 23:
State whether the following statements are true or false :
(a) Some organisms store wastes in body parts.
(b) The value of systolic pressure is always lower than that of diastolic pressure.
Solution :
(a) True.
(b) False.

Question 24:
Name the two parts of a plant through which its gaseous waste products are released into the air.
Solution :
Stomata in the leaves and lenticels in the stems are two parts through which a plant releases its gaseous waste products into the air.

Question 25:
What happens to the glucose which enters the nephron tubule alongwith the filtrate ?
Solution :
Glucose passes through the glomerulus alongwith the filtrate and gets collected in the Bowman’s capsule.

Question 26:
Name the two waste products of the human body which are produced in the body cells.
Solution :
Carbon dioxide and urea.

Question 27:
What is the role of glomerulus in the kidney ?
Solution :
The function of glomerulus is to filter the blood passing through it and initiate urine formation.

Question 28:
What is the the other name of ‘high blood pressure’ ?
Solution :
Hypertension.

Question 29:
Fill in the following blanks with suitable words :
(a) Gums and resins are the………….. products of plants.
(b) Bowman’s capsule and tubule taken together make a…………….
(c) The organs which extract the nitrogenous wastes from the blood are……………….
(d) The extracellular fluid which always flows from body tissues to the heart is called…………………
(e) The………… blood cells make antibodies whereas…………… blood cells help in respiration.
Solution :
(a) Waste.
(b) Nephron.
(c) Kidneys.
(d) Lymph.
(e) White, red.

Question 30:
What is xylem tissue ? Name the two kinds of cells in xylem tissue. State whether these cells are living or dead.
Solution :
Xylem tissue is a vascular tissue in plants which carries water and minerals from the roots to the various of the plant. Xylem tissue has two types of cells ? Xylem vessels and tracheids. Both these tissues are dead cells.

Question 31:
What is phloem tissue ? Phloem contains two types of cells joined side by side. Name these two types of cells. State whether these cells are living or dead.
Solution :
Phloem tissue is a vascular tissue which transports the food materials made in the leaves to the other parts of the plant. Phloem is made up of many cells joined end to end to form long tubes. The cells of the phloem are sieve tubes and companion cell. These are living cells.

Question 32:
(a) What is transpiration ?
What do you mean by ‘translocation’ with respect to transport in plants ?
Which plant tissue is involved in translocation : xylem or phloem ?
Solution :
(a) The evaporation of water from the leaves of the plants is called transpiration.(b) The transport of food from the leaves to the other parts of the plant is called translocation.(c) Phloem.

Question 33:
(a) Draw a labelled diagram of (z) a xylem vessel, and (ii) a sieve tube (or phloem).
(b) What are the differences between the transport of materials in xylem and phloem ?
Solution :

(a) (i)

The Structure of xylem vessels

(ii)

The Structure of phloem (made of sieve tubes)

(b)

Question 34:
Match the terms in column I with their uses in column II 

Solution : 

Question 35:
Define excretion. Name the excretory unit of a kidney.
Solution :
The process of removal of toxic waste from the body of an organism is called excretion. The excretory unit of a kidney is called nephron.

Question 36:
(a) What job is done by the kidneys ?
(b) What do kidneys excrete ?
(c) What is the name of the tubes which connect the kidneys to bladder ?
(d) What does the bladder in our body do ?
Solution :
(a) The kidneys remove the poisonous substance urea, other waste salts and excess water from the blood in the form of yellowish liquid called urine.(b) Urea.(c) Ureters.(d) Urinary bladder is a bag which stores the urine temporarily till it is excreted out.

Question 37:
Why do some people need to use a dialysis machine ? What does the machine do ?
Solution :
When there is a kidney failure then dialysis machine is used. Dialysis cleans the blood of a person by separating the waste substance (urea) from the blood.

Question 38:
What is the liquid part of the blood called ? What is the function of platelets in the blood ?
Solution :
The liquid part of the blood is called plasma. Platelets help in the coagulation of blood in a cut or wound.