NCERT Solutions Class 10 Science Chapter 6 Life Processes
NCERT Solutions Class 10 Science Chapter 6 Life Processes: National Council of Educational Research and Training Class 10 Science Chapter 6 Solutions – Life Processes. NCERT Solutions Class 10 Science Chapter 6 PDF Download.
NCERT Solutions Class 10 Science Chapter 6: Overview
Board |
NCERT |
Class |
10 |
Subject |
Science |
Chapter |
6 |
Chapter Name |
Life Processes |
Topic |
Exercise Solutions |
NCERT Solutions Class 10 Science Chapter 6 – Life Processes
Questions asked in the boxes:
Page 95
1.) Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?
Ans unicellular organisms can meet their oxygen requirement through the process of diffusion which is in direct contact with the environment. Where In multi-cellular organisms like humans, the oxygen requirement for huge no. of cells is very high and also, all the body cells are not in direct contact with the surroundingenvironment to take in the oxygen through the process of diffusion. Hence, diffusion is insufficient to meet the oxygen requirements of multicellularorganisms like humans
2.) What criteria do we use to decide whether something is alive?
Ans. Live organisms grow over time, they show some body movement, exchange of gases by the process of respiration, they intake food and excrete waste products from their body. So, these criteria should be used while deciding something is alive.
3.) What are outside raw materials used for by an organism?
Ans. food for nutrition, gases such as oxygen used during respiratory process, water to maintain turgidity in cells, sunlight used by the plants for photosynthesis, all this makes the raw materials used by an organism.
4.) What processes would you consider essential for maintaining life?
Ans. all the life processes such as respiration, nutrition, excretion are essential for maintaining life.
Page 101
1.) What are the differences between autotrophic nutrition and heterotrophicnutrition?
Ans. in autotrophic mode of nutrition, the organisms are able to synthesize their own food materials utilizing simple inorganic substances. Ex- plants. Whereas, heterotrophs following heterotrophic nutrition cannot synthesize their own food material and hence depends on autographs for their nutrition to takes place. Ex- animals including humans.
2.) Where do plants get each of the raw materials required for photosynthesis?
Ans. plants need sunlight, water, carbon dioxide and chlorophyll pigment to carry out photosynthesis. Sun is the source of sulight which is available to plants in plenty of amount during the daytime. Water is taken up from the soil by the roots of plants. Plants get carbon dioxide through air via stomatal pores whereas chlorophyll pigment is an cell organelle present in plants in their chloroplasts.
3.) What is the role of the acid in our stomach?
Ans. hydrochloric acid is present in our stomach. The hydrochloric acid creates an acidic medium in stomach whichfacilitates the action of the enzyme pepsin thus helps us to digest proteins.
4.) What is the function of digestive enzymes?
Ans. digestive enzymes help us to digest the food materials and helps us in their breakdown into simple products.
5.) How is the small intestine designed to absorb digested food?
Ans. the small intestine is the lengthiest part of the digestive system. The inner
lining of the small intestine is provided with number of finger-like projections called as villi which increases the surface area for absorption of digested food material. This villi are richly supplied with blood vessels to directly dissolve this digested food and transport it across the cells of body.
Page 105
1.) What advantage over an aquatic organism does a terrestrial organism
have with regard to obtaining oxygen for respiration?
Ans. terrestrial organism have lots of oxygen available to inhale from the air directly whereas, the aquatic organisms need to remain dependant on the dissolved oxygen present in the water body and they have no further choice to get oxygen. This is the advantage of aquatic organism have over a terrestrial organismwith regard to obtaining oxygen for respiration
2.) What are the different ways in which glucose is oxidized to provide energy in various organisms?
Ans. there can be three ways by which glucose is oxidized to provide energy in various organisms. In the first step, a six- carbon glucose is broken down into a three- carbon pyruvate. This pyruvate can be then oxidized to release energy or if the oxygen is absent as in case of anaerobic respiration, it may be converted into ethanol and carbon dioxide called fermentation which takes place in yeast or it may be converted into lactic acid to release energy as in muscle cells of our body.
3.) How is oxygen and carbon dioxide transported in human beings?
Ans. Haemoglobin pigment present in red blood cells have large affinity for oxygen.It combines with oxygen temporarily, and form oxyhaemoglobin and is carried out from lungs to the various parts of the body. Carbon dioxide is highly soluble in water and hence it is mostly transported in dissolved form in our blood plasma.
4.) How are the lungs designed in human beings to maximize the area for exchange of gases?
Ans. humans have two lungs in their body. This lungs further divide into two bronchioles and then they divide into numerous balloon like alveoli. This alveoli have numerous blood capillaries around them to maximize the area for exchange of the gases to take place.
Page 110
1.) What are the components of the transport system in human beings?
Ans. heart, blood and blood vessels are the components of transport system in human beings.
What are the functions of these components?
Ans. heart is the pumping organ of our body which regularly pumps blood throughout or body. Blood is a fluid connective tissue which contains plasma, blood cells and dissolved nutrient in it. Blood vessels like arteries, capillaries and veins regulated the blood flow and its direction.
2.) Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?
Ans. mammals and the birds are evolved animals that are warm blooded and need to keep their body temperature constant. Mixing of oxygenated and deoxygenated blood can lead to physiological problems among them. Hence, it is necessary to keep separate the oxygenated and deoxygenated blood in mammals and the birds.
3.) What are the components of the transport system in highly organized plants?
Ans. xylem (water conducting tissue) and phloem (food conducting tissue) are the components of transport system in the highly organized plants.
4.) How are water and minerals transported in plants?
Ans. minerals are get dissolved in water. Then, this water along with the dissolved minerals are get transported in plants via conducting tissue called as xylem.Water is get absorbed by the roots present under the soil to various parts of the plant body.
5.) How is food transported in plants?
Ans. food is transported in plants via food conductive tissue known as phloem from the leaves where it is synthesized to the other parts of the plant body.
Page 112
1.) Describe the structure and functioning of nephrons.
Ans. nephrons are the structural and functional units of kidney. They consists of two components as Bowman;s capsule and glomerulus. Bowman;s capsule is a cup- shaped structure whereas glomerulus is a net of blood capillaries around Bowman;s capsule. The main function of nephron is blood filteration and reabsorption of water and other essential molecules from the filterate.
2.) What are the methods used by plants to get rid of excretory products?
Ans. plants use various methods to excrete the waste products produced in them. Oxygen is a byproduct generated during the process of respiration is given out with the help of stomatal pores. Waste materials generated may be stored in the cell-vacuoles of plant cell and then excreted along with dead and falling leaf. Gum is also a type of excretory product of plant. It can also be excreted into the surrounding soil with the help of roots as resin.
3.) How is the amount of urine produced regulated?
Ans. the amount of urine produced depends upon the amount of excess water present in the body and the dissolved wastes that are created inside the body.
Exercise Solution:
1.) The kidneys in human beings are a part of the system for
(a) nutrition. (c) excretion.
(b) respiration. (d) transportation.
Ans. c. excretion
2.) The xylem in plants are responsible for
(a) transport of water. (c) transport of amino acids.
(b) transport of food. (d) transport of oxygen.
Ans. a. transport of water
3.) The autotrophic mode of nutrition requires
(a) carbon dioxide and water. (c) sunlight.
(b) chlorophyll. (d) all of the above.
Ans. d. all of the above
4.) The breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(a) cytoplasm. (c) chloroplast.
(b) mitochondria. (d) nucleus.
Ans. b. mitochondria
5.) How are fats digested in our bodies? Where does this process take place?
Ans.Bile juice secreted by liver accomplishes digestion of the fats inside the body. Fats are present in the intestine in the form of large fat globules which are difficult for the proper enzyme action on them. Bile salts breakdown this large fats molecules into smaller fat globules increasing the efficiency of enzyme action on fats similar to the process of emulsification of fats. The pancreas secretes pancreatic juice which contains enzyme called lipase which helps for breaking down of emulsified fats. The wall of the small intestine contains glands which secrete intestinal juicewhich converts fats into fatty acids and glycerol.
Alternative Answer –
When food coming from stomach it is acidic and it is in the form of carbohydrates, protein and fats. Secretion of liver and pancreas are used to digest this, but when fats are enter in small intestine it is in the form of large globules, it is difficult for digest large globules for the enzymes to act on them. Then the Bile salts which it gets from liver is breakdown the large globules into small size of globules to increase the action of enzymes. Finally fats are converted into fatty acids and glycerol. Digestion process of fats proteins and carbohydrates are takes place in small intestine.
6.) What is the role of saliva in the digestion of food?
Ans. salivary glands secrete saliva. Saliva contains an Enzyme in it which is called as salivary amylase that breaks down complex molecule, starch into a simple sugar. The food in mouth is mixed thoroughly with saliva to make food wet so that its passage into the alimentary canal would be smooth.
Alternative Answer –
When we eat food, our mouth becomes waters. This fluid is known as saliva secreted by the salivary glands. The saliva contains the enzyme called salivary amylase this enzyme contains the capacity to break down the starch to give simple suger. When we eat food in our mouth, saliva is mixed with food and chewing by the musclar tongue and the saliva helps the food digestion and it protects the mouth from bacterial infection.
7.) What are the necessary conditions for autotrophic nutrition and what are its byproducts?
Ans. Availability of sunlight, water, carbon dioxide and chlorophyll pigment are the necessary conditions for autotrophic nutrition. Glucose and oxygen are its byproducts.
Alternative Answer –
When the autotrophs takes substance from outside, then make energy and stored it, this process is known as autotrophic nutrition. In this process autotrophs use carbon dioxide and water and convert into energy in presence of sunlight and chlorophyll and stored it. Therefore the necessary condition for autotrophic nutrition is carbon dioxide and water, sunlight and chlorophyll. And food which is in the form of glycogen and oxygen are the by products of autotrophic nutrition.
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8.) What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.
Ans. Aerobic respiration requires oxygen to occur whereas the respiration which can be done even in absence of the oxygen is called as anaerobic respiration. Energy release in aerobic respiration is always greater than that of anaerobic respiration. organisms that use the anaerobic mode of respiration are yeast, etc.
Alternative Answer –
Aerobic respiration |
Anaerobic respiration |
1. Its pathway depends on oxygen. | Its pathway is not depends on oxygen. |
2. During this process large amount of energy will be released. | During this process small amount of energy will be released. |
3. The weast product of this process is water and carbon dioxide. | The weast product of this process is lactic acid or ethanol and carbon dioxide. |
4. This process occurs in both cytoplasm and mitochondria. | This process occurs only in cytoplasm. |
5. In this process glucose is completely oxidised. | In this process glucose is incompletely oxidised. |
The organisms that use the anaerobic mode of respiration is : Yeast, Protozoan bacteria, lactobacillus
9.) How are the alveoli designed to maximize the exchange of gases?
Ans. Within our lungs, we have smaller and smaller tubes which finally terminate in balloon-like structures called as alveoli. This alveoli provides a surface for exchange of gases to take place by having extensive network of blood vessels.
Alternative Answer –
In side of the lungs,the passages are divided into so many smaller and smaller tubes and finally it is in balloon like structure called alveoli. The walls of alveoli connected to the blood vessels. When we breathe the air will be sucked by lungs and air will be reach these alveolar cell, because of that it connected to blood vessels the oxygen will be transferred from alveolar cell to blood vessel and flow through in our body and Carbon dioxide which is present in the rest of the body is release the alveoli and it goes out side from the body. This process is done by during the breathing cycle the lungs take sufficient air and transfer oxygen in our body and release the carbon dioxide from the body.
10.) What would be the consequences of a deficiency of haemoglobin in our bodies?
Ans. haemoglobin has very high affinity for oxygen. It is responsible for transportation of oxygen molecule in the body of human being. If there is deficiency of haemoglobin in our body, then our body will be deprived of enough oxygen and we would suffer from anemia.
Alternative Answer –
The work of heamoglobin is to transfer the oxygen throughout the body. It present in red blood cells. When the heamoglobin counts is decreases then the capacity of heamoglobin will be decreases, in this reason oxygen will be not supply sufficiently throughout in our body. When the heamoglobin count is decreases then we notice that suddenly weakness will be appears in our body and sometimes breathlessness problem will also appears.
11.) Describe double circulation of blood in human beings. Why is it necessary?
Ans. the movement of blood occurs twice in the heart hence it is called as double circulation which takes place in human beings. Oxygen-rich blood from the lungs comes in to left atrium. Contraction of left atrium pushes the oxygenated blood into the left ventricle. When the left ventricle contracts, the oxygenated blood is pumped out to whole body with the help of aorta. De-oxygenated blood comes from the body in right atrium. As the right atrium contracts, blood flows into the right ventricle. The deoxygenated blood is then pumped towards the lungs for oxygenation.
Alternative Answer –
The human body contains the four chambered heart in which two are auricle and two are ventricle, the blood travel twice through the heart to separate oxygenated blood and de-oxygeneted blood this process is known as double circulation
This process contains two circuits
- System circulation:
In this circulation oxygenated blood goes to left auricle to left ventricle and enter aorta. And aorta sends the blood throughout the body parts and veins receive the blood which contains carbon dioxide from different body parts and it send this blood into right atrium to right ventricle.
- Pulmonary circulation:
In this circulation the vein collect the de-oxygeneted blood from different body parts and send through right ventricle to lungs and take oxygenated blood from lungs and sends the left auricle.
These two process together called double circulation.
An human body contains four chambered heart in which all four chambers duty is, separate the oxygenated and de-oxygeneted blood. In other words keeping the oxygenated and de-oxygeneted bloods from mixing. And to get energy to maintain the temperature of human body.
12.) What are the differences between the transport of materials in xylem and phloem?
Ans. xylem conducts water and dissolved minerals through it whereas phloem is responsible for the conduction of food materials within the plants. This is the difference between the transport of materials in xylem and phloem.
Alternative Answer –
Xylem transport |
Phloem transport |
1. The duty of xylem transportation is single direction or upward direction only. | The duty of phloem transportation is multi direction or both upward and downward direction. |
2. Its duty is transfer the water and minerals which is obtained from the soil. | Its duty is transfer the product of photosynthesis or food and other substances from leaves. |
3. The cells of xylem are created from dead cells. | The cells of phloem are created from living cells. |
4. Because of that it created from dead cells ,the Walls of the xylem cells are very thick. | Because of it created from living cells ,the Walls of the phloem cells are very thin. |
5. The xylem cells present in center of vascular bundle. | The phloem cells present in outside of vascular bundle. |
13.) Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning.
Ans.
Alveoli | Nephrons |
Is a part of respiratory system | Is a part of excretory system |
It is a balloon like structure | It has a cup-shaped end called Bowman’s capsule, glomerulus and lots of blood vessels |
Provides a surface for the exchange of gases to take place inside the lungs | Are the filteration units present in kidneys |
Helps in respiration | Helps in excretion |
Alternative Answer –
Alveoli |
Nephron |
1. In side the lungs the packages are divided into so many smaller and smaller tubes and finally it is in balloon like structure called alveoli. | In side the capillary cluster of the kidney there are many cup-shaped end of coilled tubes which collect the filtrate, each kidney has large amount of these types of filtrations called nephrons. |
2. The duty of each alveoli is exchange gases between the lungs and blood vessels. | The duty of nephron is to filtrate the blood through kidney. |
3. The alveoli are present in respiratory system | The nephron are present in excretory system. |
4. The blood is supplied from alveoli to pulmonary venules. | The blood is supplied from nephron to renal vein. |
5. There are 480 millions of alveolis are present in each lung. | There are 1.5 millions of nephrons are present in each kidney. |
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