RBSE Class 10 Science Solutions Chapter 6 Life Processes

RBSE Class 10 Science Solutions Chapter 6 Life Processes

RBSE Class 10 Science Chapter 6 Life Processes InText Questions and Answers

Page 95.

Question 1.
Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like human?
Answer:
In multicellular organisms like humans all the cells are not in direct contact with the surrounding environment. Thus, simple diffusion will not meet the oxygen requirements.

Question 2.
What criteria do we use to decide whether something is alive?
Answer:
Something is alive, for this the following characters should be present:

• The body of living things are made up of cell cellstissues.
• Living things have different metabolic reactions, as digestion, respiration etc.
• Living thing grow and show movement.
• Living beings have definite size and shape.
• Living beings die and they increase their offsprings by reproduction.

Question 3.
What are outside raw materials used by an organism?
Answer:
Organisms used the carbon based molecules as a raw material because life on earth is depend on carbon based molecules so mostly food materials is based on carbon.

Question 4.
What processes would you consider essential for maintaining life?
Answer:
For maintenance of life following processes are necessary:

• nutrition
• metabolism
• respiration
• transportation.

Page 101.

Question 1.
What are the differences between autotrophic nutrition and heterotrophic nutrition?
Answer:
Difference in autotrophic nutrition and hetero-trophic nutrition:

Question 2.
Where do plants get each of the raw materials required for photosynthesis?
Answer:
Plants get the raw materials required for photosynthesis light from sun and supply of water from available water in soil by absorption of roots. Other materials like nitrogen, phosphorus, iron and magnesium are taken up from the soil. Carbon dioxide is taken from atmosphere.

Question 3.
What is the role of acid in our stomach?
Answer:
The wall of the stomach has gastric glands which secrete gastric juice. It is acidic because it consists hydrochloric acid. This acid is having the following role:

• It prevent the food from decaying.
• It provides acidic medium and it helps in activity of pepsin enzyme.
• HCl help in dissolving the hard tissues.
• It sterlized the food.

Question 4.
What is the function of digestive enzymes?
Answer:
Digestive enzymes are organic biocatalysts. They increase the rate of different biochemical reactions. The main function of digestive enzymes are the digestion of food i.e. to convert the complex and insoluble food into simple and soluble food.

Question 5.
How is the small intestine designed to absorb digested food?
Answer:
The inner lining of the small intestine has numerous finger like projections called villi which increase the surface area for absorption. The villi are richly supplied with blood vessels which take the absorbed food to each and every cell of the body.

Page 105.

Question 1.
What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
Answer:
Animals that live in water need to use the oxygen dissolved in water. Since the amount of dissolved oxygen is fairly low compared to the amount of oxygen in the air, the rate of breathing in aquatic organisms is much faster than that seen in terrestrial organisms. Terrestrial organisms use the oxygen in the atmosphere for respiration. This oxygen is absorbed by different organs in different animals. All these organs have a structure that increases the surface area which is in contact with the oxygen-rich atmosphere.

Question 2.
What are the different ways in which glucose is oxidised to provide energy in various organisms?
Answer:
For various biological activities necessary energy obtained from oxidation of glucose, which is stored in form of ATP. Oxidation of glucose in different organism takes place in following ways:
1. Aerobic respiration:
When oxidation of glucose takes place in cytoplasm in presence of oxygen, it is called aerobic respiration. In most of the organisms energy in produced by this method. ‘

2. Anaerobic respiration:
If oxidation of glucose takes place in absence of oxygen, then it is called anaerobic respiration. During fermentation this process takes place in yeast, here pyruvate may be convereted into ethanol and carbon dioxide. Sometimes, when there in a lack of oxygen in our muscle cells, then pyruvate is converted into lactic acid which is also a three-carbon molecules.

Question 3.
How is oxygen and carbon dioxide transported in human beings?
Answer:
In human beings, the respiratory pigment is haemoglobin which has a very high affinity for oxygen. This pigment is present in the red blood corpuscles. Thus, oxygen diffuses from alveoli and it bind with the haemoglobin molecule. Blood carry this oxygen to the tissues which are deficient in oxygen. Carbon dioxide is more soluble in water and hence is mostly transported in the dissolved form in our blood. Due to less concentration of CO₂ in alveoli air it diffuses from blood and comes to lungs. This CO₂ containing air release from body by expiration.

Question  4.
How are the lungs designed in human beings to maximise the area for exchange of gases?
Answer:
In human there are two lungs, which are called left and right lung. Within the lungs, the passage divides into smaller and smaller tubes which finally terminate in balloon like structures which are called alveoli. The alveoli provide a surface where the exchange of gases can take place. Surrounding the alveoli there is an extensive network of bloodvessels, which act as respiratory surface. If we spread all the alveoli surface of two lungs of an adult human being it will cover approximately 80 m₂ area. Thus, the alveoli situated in lungs provide extensive area for gaseous exchange.

Page 110.

Question 1.
What are the components of the transport system in human being? What are the functions of these components?
Answer:
In human being there are two main components of transport system, which are called:
(a) Circulatory system
(b) Lymphatic system.
(a) Circulatory system: Circulatory system consist the following three parts.
(1) Heart: It is a muscular organ which contract to pump the blood in complete body.

(2) Blood: Blood consists of a fluid medium called plasma in which the free cells are present in form of blood cells. These blood cells are of three types:
(i) Functions of Red blood corpuscles:
They transport oxygen from the lungs to tissues and carries carbon dioxide from cells to lungs.

(ii) Functions of white blood corpuslces:
They perform the function of phagocytosis and make antibodies.

(iii) Functions of Platelets:
They help in clotting of blood, by this they stop the bleeding from cut part of blood vessels. Functions of Plasma:
(i) Plasma transports food, carbon dioxide and nitrogenous wastes in dissolved form.

(3) Blood Vessels:They are of three types:
(i) Arteries: They are thick walled blood vessels, which carry blood away from the heart to various organs of the body.

(ii) Veins: They are thin walled vessels, which collect the blood from different organs and bring it back to the heart.

(iii) Capillaries: They are very thin and narrow vessels, which joins the arteries to veins.

(b) Lymphatic system:
Through the pores present in the walls of capillaries some amount of plasma, proteins and blood cells escape into intercellular spaces in the tissues to form the tissue fluid or lymph. It is similar to the plasma of blood but colourless and contains less protein. Lymph drains into lymphatic capillaries from the intercellular spaces, which join to form large lymph vessels that finally open into larger veins. Lymph carries digested and absorbed fat from intestine and drains excess fluid from extra cellular space back into the blood.

Question 2.
Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?
Answer:
The separation of the right side and the left side of the heart is useful to keep oxygenated and deoxygenated blood from mixing. Such separation allows a highly efficient supply of oxygen to the body. This is useful in animals that have high energy needs, such as birds and mammals, which constantly use energy to maintain their body temperature. Thus it is necessary to separate oxygenated and deoxygenated blood in mammals and birds.

Question 3.
What are the components of the transport system in highly organised plants?
Answer:
In highly organised plants the transport system consists the following two components: (1) Xylem (2) Phloem.
(1) Xylem: It is also called water conducting tissue. Its main functions is to transport the water and mineral salts absorbed by roots to different parts of the plant.

(2) Phloem: Its main function is to transport the organic food material and hormones prepared in photosynthesis by leaves to each parts of the plant.

Question 4.
How are water and minerals transported in plants?
Answer:
In plants transportation of water and mineral salts takes place through xylem. In 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.

There is steady movement of water into root xylem, creating a column of water that is steadily pushed upwards.The water which is lost through the stomata is replaced by water from the xylem vessels in the leaf. In fact, evaporation of water molecules from the cells of a leaf creates a suction which pulls water from the xylem cells of roots. Thus transpiration helps in the absorption and upward movement of water and minerals dissolved in it from roots to the leaves.

Question 5.
How is food transported in plants?
Answer:
The transport of soluble products of photosynthesis is called translocation and it occurs in the part of the vascular tissue known as phloem. Besides the products of photosynthesis, the phloem transports amino acids and other substances. These substances are especially delivered to the storage organs of roots, fruits and seeds and to growing organs. The translocation of food and other substances takes place in the sieve tubes with the help of adjacent companion cells both in upward and downward direction.

The transportation of food in phloem is achieved by utilising energy. Material like sucrose is transferred into phloem tissue using energy from ATP. This increases the osmotic pressure of the tissue causing water to move into it. This pressure moves the material in the phloem to tissues which have less pressure. This allows the phloem to move material according to the plant’s needs.

Page 112.

Question 1.
Describe the structure and functioning of nephrons.
Answer:
Structure of Nephron Each kidney has large numbers of filtration units called nephrons. In these filtration units there is a cluster of very thin blood capillaries, which is called glomerulus. In the kidney, each glomerulus is inside the cup-shaped end of a coiled tube which is called Bowman’s capsule. The tube collects the flitted urine.

Functioning of Nephron Some substances in the initial filtrate, such as glucose, amino acids, salts and a major amount of water, are selectively reabsorbed as the urine flows along the tube. The amount of water reabsorbed depends on how much excess water there is in the body, and an how much of dissolved waste there is to be excreted. The urine formation in each kidney eventually enters a long tube, the ureter, which connects the kidney with the urinary bladder.

Question 2.
What are the methods used by plants to get rid of excretory products?
Answer:
Plants get rid of excretory products by using the following methods:
(i) In plants CO₂ is main excretory material in respiration. The plants get rid of CO₂ and water vapour formed in respiration by common diffusion through stomata and lenticles.

(ii) Plants excretory waste materials sent to leaves, bark and fruits. Plants get rid of these when they seperate from plants.

(iii) Many excretory materials stored in vacuoles of cells.

(iv) Other waste products are stored as resins and gums, especially in old xylem.

(v) Some excretory materials are released by roots of the plants in the soil.

Question 3.
How Is the amount of urine produced regulated?
Answer:
The regulation of the amount of urine produced depends on how much excess water there is in the body, and on how much of dissolved waste there is to be excreted.

RBSE Class 10 Science Chapter 6 Life Processes Textbook Questions and Answers

Question 1.
The kidneys in human beings are a part of the system for:
(a) nutrition
(b) respiration
(c) excretion
(d) transportation
Answer:
(c) excretion

Question 2.
The xylem in plants are responsible for:
(a) transport of water
(b) transport of food
(c) transport of amino acids
(d) transport of oxygen.
Answer:
(a) transport of water.

Question 3.
The autotrophic mode of nutrition requires:
(a) carbon dioxide and water
(b) chlorophyll
(c) sunlight
(d) all of the above
Answer:
(d) all of the above

Question 4.
The breakdown of pyruvate to give carbon dioxide, water and energy takes place in:
(a) cytoplasm
(b) mitochondria
(c) chloroplast
(d) nucleus.
Answer:
(b) mitochondria.

Question 5.
How are fats digested in our bodies? Where does this process take place ?
Answer:
In our body the digestion of fat takes place by lipase enzyme in alimentary canal. Bile salts present in bile juice does the emulsification of fat that is break the fat into small globules. Due to this the efficiency of enzyme increases. This is similar to the emulsifying action of soaps on dirt. Lipase enzyme present in digestive juice, pancreatic juice and intestinal juice converts this emulsified fats into fatty acids and glycerol. In this way fat is digested. The digestion of fats takes place in small intestine.

Question  6.
What is the role of saliva in the digestion of food?
Answer:

• Saliva wetted the food to make its passage smooth. .
• The saliva contains an enzyme called salivary anylase that breaks down starch which is a complex molecule to give simple sugar.

Question 7.
What are the necessary conditions for autotrophic nutrition and what are its products?
Answer:
The necessary conditions for autotrophic nutrition are as:

• Carbon dioxide
• Chlorophyll present in plants
• Sun light
• Water
• Appropriate temperature

Autotrophs in presence of sunlight with the help of chlorophyll by using CO₂and water synthesize the food (carbohydrate). This process is called photosynthesis.

In this process the main product is glucose (C₆H₁₂O₅) and byproduct is water and oxygen.

Question 8.
What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.
Answer:

Question 9.
How are the alveoli designed to maximise the exchange of gases.
Answer:
The smallest unit of lungs are alveoli. The alveoli provide a surface where the exchange of gases can take place. The walls of the alveoli contain an extensive network of blood vessels. If the human both lungs alveolar surface were spread out, it would cover about 80 meter square area. Thus alveoli provide extensive surface for gaseous exchange and in this way more efficient gas exchange takes place.

Question 10.
What would be the conse¬quences of deficiency of haemoglobin in our body?
Answer:
The main function of haemoglobin in our body is to receive oxygen from lungs and transport it to various tissues of the body. So it is also called respiratory pigment. Due to the defeciency of haemoglobin there will be less availability of oxygen to body cells from lungs. Ultimately the oxidation of food material will be affected. The conduction of different reactions in our body will also get less essential energy. By this health may affected and get tired. Defeciency of haemoglobin cause anaemia disease. Even in much defeciency condition, patient becomes pale and can die.

Question 11.
Describe double circulation in human beings. Why is it necessary?
Answer:
Blood goes through the heart twice during each cycle (each course of circulation) it is called double circulation.
Deoxygeneted blood collected from different parts of body pass to great veins and finally blood reaches in right atrium. This blood pass from right atrium to right ventricle. Deoxygeneted blood from right ventricle is pumped out to lungs where it gets oxygeneted. Oxygeneted blood again comes to left atrium in human heart. It comes from left atrium to left ventricle, left ventrical to aorta and then moves to body. In this way in one circulation cycle blood goes through the heart twicely one time from right side and second time from left side. So it is called double circulation.

Significance: The separation of the right side and the left side of the heart is useful to keep oxygenated and deoxy – genated blood from mixing. Such separation allows a highly efficient supply of oxygen to the body so that human can constantly use this energy to maintain their body temperature.

Question 12.
What are the differences between the transport of materials in Xylem and phloem?
Answer:
The xylem moves water and minerals obtained from the soil whereas phloem transports products of photosynthesis from the leaves where they are synthesised to other parts of the plant.

Question 13.
Compare the functioning of alveoli in the lungs and nephrons in the kidney with respect to their structure and functioning.
Answer: Differences between alveoli and nephrons: