Life Processes - Class 10 Science - Chapter 5 - Notes, NCERT Solutions & Extra Questions
Renews every month. Cancel anytime
Your personal doubt-solving assistant
Chatterbot AI gives you 100% accurate answers to your questions in an instant.
Notes - Life Processes | Class 10 NCERT | Science
Introduction to Life Processes
Life processes are fundamental activities that living organisms undergo to maintain life. These processes include nutrition, respiration, transportation, and excretion. Understanding these processes is crucial as it helps differentiate living beings from non-living entities and explains how organisms sustain themselves.
Characteristics of Living Organisms
Movement and Life
While visible movement, such as a dog running or a plant bending towards light, indicates life, it's not a sole criterion. Molecular movements within cells, like transport of substances and metabolic reactions, are essential and often invisible.
Growth and Development
Living organisms grow and develop throughout their life. For instance, plants grow towards sunlight, and animals grow from infancy to adulthood. This growth is a clear indication of life.
Nutrition as a Life Process
Types of Nutrition
Autotrophic Nutrition
Autotrophs, like green plants, synthesize their food through photosynthesis, which utilizes sunlight, carbon dioxide, and water to produce carbohydrates.
Photosynthesis Steps:
Absorption of light energy by chlorophyll.
Conversion of light energy to chemical energy and splitting water molecules.
Reduction of carbon dioxide to carbohydrates.
Heterotrophic Nutrition
Heterotrophs, such as animals and fungi, obtain complex food materials from other organisms. The food needs to be broken down into simpler substances before being utilized for body functions.
Comparative Nutrition Strategies
Autotrophs, like green plants, rely on inorganic sources for food, whereas heterotrophs depend on organic materials. For example, while plants make their food through photosynthesis, humans consume food to obtain energy and nutrients.
Respiration in Living Organisms
Process of Respiration
Respiration is essential for breaking down food substances to release energy. It can be aerobic (with oxygen) or anaerobic (without oxygen).
Aerobic vs Anaerobic Respiration
In aerobic respiration, glucose breaks down into carbon dioxide and water, providing more energy. Anaerobic respiration results in lactic acid or ethanol and carbon dioxide and occurs in the absence of oxygen.
Respiratory Systems across Species
Different organisms have specialized structures for respiration:
Fish: Use gills to extract oxygen from water.
Humans: Use lungs to intake oxygen from the air.
Plants: Exchange gases through stomata on leaves.
Transportation of Substances
Circulatory Systems in Animals
Human Heart and Blood Vessels
The human circulatory system consists of the heart, blood, and blood vessels, transporting oxygen, nutrients, and waste products.
Key Components:
Heart: Pumps blood through the body.
Arteries: Carry oxygenated blood away from the heart.
Veins: Return deoxygenated blood to the heart.
Capillaries: Facilitate exchange of substances between blood and tissues.
Double Circulation in Humans
Double circulation ensures separation of oxygenated and deoxygenated blood, enhancing respiration efficiency.
Transport Systems in Plants
Plants use xylem and phloem tissues for transportation:
Xylem: Transports water and minerals from roots to other parts.
Phloem: Distributes the products of photosynthesis from leaves to various parts.
Excretion and Waste Management
Excretion in Humans
The human excretory system, consisting of kidneys, ureters, bladder, and urethra, removes waste products like urea from the blood.
Key Processes:
Blood is filtered in kidneys.
Waste forms urine, stored in the bladder, and expelled through the urethra.
Artificial Kidney (Hemodialysis)
In case of kidney failure, an artificial kidney removes waste through dialysis, mimicking natural kidney function without reabsorption.
Excretion in Plants
Plants excrete waste by:
Storing waste in cellular vacuoles.
Shedding waste-laden parts like leaves.
Excreting compounds into surrounding soil.
Conclusion
Understanding life processes is essential to grasp how organisms survive, grow, and interact with their environment. These processes form the basis of biological functions and are crucial in fields like medicine, agriculture, and environmental science.
🚀 Learn more about Notes with Chatterbot AI
Extra Questions - Life Processes | NCERT | Science | Class 10
💡 Have more questions?
Ask Chatterbot AINCERT Solutions - Life Processes | NCERT | Science | Class 10
The kidneys in human beings are a part of the system for
(a) nutrition.
(c) excretion.
(b) respiration.
(d) transportation.
The kidneys in human beings are a part of the system for:
(c) excretion.
Kidneys are responsible for filtering waste products from the blood and excreting them in the form of urine, which makes them an essential component of the excretory system in the human body.
The xylem in plants are responsible for
(a) transport of water.
(c) transport of amino acids.
(b) transport of food.
(d) transport of oxygen.
The xylem in plants is responsible for:
(a) transport of water.
The autotrophic mode of nutrition requires
(a) carbon dioxide and water.
(c) sunlight.
(b) chlorophyll.
(d) all of the above.
The autotrophic mode of nutrition requires: (d) all of the above.
Autotrophs need carbon dioxide and water to perform photosynthesis, sunlight to provide the energy for the process, and chlorophyll (or a similar pigment in some organisms) to absorb the sunlight and facilitate the conversion of carbon dioxide and water into glucose and oxygen.
The breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(a) cytoplasm.
(c) chloroplast.
(b) mitochondria.
(d) nucleus.
The breakdown of pyruvate to give carbon dioxide, water, and energy takes place in:
(b) mitochondria.
This process is part of cellular respiration and occurs in the mitochondria of the cell, where pyruvate undergoes oxidative phosphorylation to produce ATP, the energy currency of the cell.
How are fats digested in our bodies? Where does this process take place?
Fats are digested in our bodies primarily in the small intestine. The process involves several steps:
Emulsification of Fats: When fats enter the small intestine, they are in the form of large globules which are difficult for enzymes to act upon. Bile salts secreted by the liver into the small intestine break these down into smaller globules, increasing the efficiency of enzyme action. This step is much like the emulsifying action of soaps on dirt, as it makes the fats more accessible to the digestive enzymes .
Digestion by Enzymes: The pancreas secretes pancreatic juice into the small intestine, which contains digestive enzymes such as lipase that break down these emulsified fats. The walls of the small intestine also contain glands that secrete intestinal juice. The enzymes in these juices finally convert fats into fatty acids and glycerol .
Hence, the digestion of fats occurs in the small intestine with the help of bile and pancreatic and intestinal enzymes.
What is the role of saliva in the digestion of food?
The role of saliva in the digestion of food is multifaceted. Saliva, secreted by the salivary glands, acts primarily in the oral cavity, where it moistens the food, making it easier to chew and swallow. It also helps to create a food bolus that can be easily pushed down the esophagus. Importantly, saliva contains the enzyme salivary amylase, which starts the process of breaking down complex carbohydrates (starch) into simpler sugars. This enzymatic digestion of starch by salivary amylase is an initial step in the chemical digestion of food .
What are the necessary conditions for autotrophic nutrition and what are its byproducts?
The necessary conditions for autotrophic nutrition include carbon dioxide and water, chlorophyll, and sunlight. The byproducts of autotrophic nutrition are not mentioned in the provided text, but typically, the byproducts are oxygen and glucose, which are produced through the process of photosynthesis.
What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.
Aerobic and anaerobic respiration are two modes of cellular respiration that cells undergo to produce energy. Here are the main differences between them:
Presence of Oxygen: Aerobic respiration occurs in the presence of oxygen, while anaerobic respiration takes place in the absence of oxygen.
Location within the Cell: The breakdown of pyruvate using oxygen in aerobic respiration takes place in the mitochondria, whereas anaerobic respiration takes place in the cytoplasm.
End Products: Aerobic respiration converts pyruvate into carbon dioxide and water, releasing a significant amount of energy. Anaerobic respiration, such as in yeast during fermentation, converts pyruvate into ethanol and carbon dioxide, and in muscle cells, it converts pyruvate into lactic acid.
Energy Yield: Aerobic respiration releases more energy compared to anaerobic respiration. This is because the complete oxidation of glucose occurs in aerobic respiration, leading to a higher production of ATP.
Some organisms that use the anaerobic mode of respiration include yeast, which undergoes fermentation in the absence of air, producing ethanol and carbon dioxide, and certain bacteria. Also, human muscle cells can respire anaerobically during sudden activity, leading to the formation of lactic acid and causing muscle cramps .
How are the alveoli designed to maximise the exchange of gases?
The alveoli are balloon-like structures at the end of the bronchial tubes, and they are designed to maximize the exchange of gases by providing a large surface area where this exchange can take place. The walls of the alveoli contain an extensive network of blood vessels, allowing for efficient transfer of oxygen from the alveolar air into the blood and carbon dioxide from the blood into the alveoli. When we breathe in, our ribs lift and the diaphragm flattens, enlarging the chest cavity. This leads to air being sucked into the lungs and filling the alveoli. The large surface area provided by the alveoli is very efficient for gas exchange, and if spread out, the alveolar surface would cover about 80 square meters .
What would be the consequences of a deficiency of haemoglobin in our bodies?
Consequences of a deficiency of hemoglobin include:
Fatigue and Weakness: Since hemoglobin is responsible for carrying oxygen, an insufficiency would mean that the body's tissues and organs do not get enough oxygen to function properly, resulting in general fatigue and weakness.
Pale Skin and Mucous Membranes: A lower hemoglobin level can cause the skin and mucous membranes to appear paler than normal because of reduced blood flow and the lack of red blood cells.
Shortness of Breath: Individuals may experience difficulty breathing or shortness of breath, particularly with exertion, due to the body's inability to meet its oxygen requirements.
Heart Problems: The heart must work harder to pump blood to compensate for the lack of oxygen in the tissues, which can lead to an enlarged heart or heart failure over time.
Cognitive Issues: Low hemoglobin levels can cause problems such as difficulty concentrating, dizziness, and memory issues due to decreased oxygen supply to the brain.
Cold Hands and Feet: Reduced oxygen delivery can result in cold extremities.
Headaches: The brain may signal the widening of blood vessels to improve oxygen delivery, which can result in headaches.
Brittle Nails and Hair Loss: Reduced oxygen can lead to brittle nails and may affect normal hair growth, contributing to hair loss.
Increased Susceptibility to Infections: Anemia can affect the immune system, making the body more susceptible to infections.
Describe double circulation of blood in human beings. Why is it necessary?
Double circulation in human beings refers to the process where blood goes through the heart twice during each cycle of its passage through the body. This is an essential aspect of the circulatory system in higher vertebrates, including humans .
It is necessary because it ensures the efficient separation and delivery of oxygen-rich blood and carbon dioxide-rich blood. The heart has different chambers that prevent the mixture of oxygen-rich blood with the blood containing carbon dioxide. Carbon dioxide-rich blood from the body is sent to the lungs to remove carbon dioxide and pick up oxygen. The newly oxygenated blood is then brought back to the heart, which pumps it out to the rest of the body. This system ensures that organs and tissues receive a constant supply of oxygenated blood for efficient functioning.
What are the differences between the transport of materials in xylem and phloem?
The transport of materials in xylem and phloem differs in several ways:
Function: Xylem primarily moves water and minerals obtained from the soil, while phloem transports the products of photosynthesis like sucrose, amino acids, and other substances to various parts of the plant.
Direction: Transport in xylem is mainly unidirectional, from roots to the leaves. In contrast, phloem can transport substances in both upward and downward directions, moving material to storage organs such as roots, fruits, seeds, as well as to growing organs.
Mechanism: Transport in xylem can largely be explained by simple physical forces such as root pressure during the night and transpiration pull during the day. On the other hand, translocation in phloem is an active process that requires energy. Substances like sucrose are actively transported into the phloem tissue using energy derived from ATP, which increases the osmotic pressure within the tissue and causes water to move into it. This creates pressure that moves material within the phloem to tissues with lower pressure.
Energy Requirement: Transport in xylem does not require energy in the form of ATP, while phloem transport relies on energy from ATP to actively move materials according to the plant’s requirements.
Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning.
Alveoli in the lungs:
The alveoli are tiny balloon-like structures at the end of the airways in the lungs.
They are surrounded by an extensive network of blood capillaries.
The walls of the alveoli are very thin, which facilitates the exchange of gases.
When we inhale, air fills the alveoli, and oxygen diffuses across the alveolar wall into the blood capillaries, while carbon dioxide diffuses from the blood into the alveoli to be exhaled .
Nephrons in the kidneys:
Nephrons are the basic filtration units of the kidneys, consisting of a cluster of thin-walled blood capillaries associated with a structure called Bowman’s capsule, which collects the filtrate.
These nephrons are packed closely together in the kidneys.
The filtrate that is collected includes substances like glucose, amino acids, salts, and a significant amount of water. As the filtrate travels through the tubule of the nephron, these substances are selectively reabsorbed based on the body's needs; for instance, the amount of water reabsorbed depends on the body's hydration status and the amount of dissolved waste that needs to be excreted .
💡 Have more questions?
Ask Chatterbot AIExtra Questions and Answers - Life Processes | NCERT | Science | Class 10
What is the organ that pumps blood all throughout the human body?
A) Blood vessels and capillaries
B) Lungs
C) Heart
D) Kidneys
The correct answer is Option C: Heart.
The heart is responsible for pumping blood through the human body. This vital organ is a muscular, four-chambered structure, essential for circulating blood that carries oxygen and nutrients to various body tissues.
The trachea divides into two tubes at its lower end. What are the names of these tubes?
The trachea splits into two primary tubes at its lower end, which are called the left bronchus and right bronchus. These then subdivide into secondary structures named bronchioles (first into primary, then secondary, and finally tertiary bronchioles), and eventually lead to sac-like structures known as alveoli.
Expulsion of undigested waste material through the anus is known as:
A) assimilation
B) ingestion
C) egestion
D) digestion
The correct option is C) egestion.
Ingestion is the intake of food into the body.
Digestion refers to the process where food is broken down into simpler substances that can be absorbed.
Assimilation involves the absorption and use of digested food substances by the body's cells.
Egestion is the expulsion of undigested waste material through the anus.
Choose the correct statement from the following about organ transplant:
A. Transplantation is required when an organ has failed due to a disease.
B. Corneas can be donated when a person is alive.
C. A portion of the lung can be donated when a person is alive.
D. Organ transplant is a surgical procedure.
The correct options are:
A: Transplantation is required when an organ has failed due to a disease.
C: A portion of the lung can be donated when a person is alive.
D: Organ transplant is a surgical procedure.
Explanation:
Organ transplantation involves the surgical transfer of a healthy organ from a donor to a recipient whose organ has failed or is damaged, often because of illness or injury.
Organs like the corneas, heart, pancreas, and intestines are typically donated after the donor is declared brain dead.
However, certain organs and tissues, such as a kidney, a part of the liver, or a portion of the lungs, can be donated by a living donor. This makes the statement in option C correct.
Organ transplant being a surgical process, as stated in option D, is fundamentally how transplantation is performed, making it a correct statement.
The end products of glycolysis in the cytoplasm of the cell are -
A) Pyruvate
B) 2 ATP
C) $2 \mathrm{NADH}$
D) 3 ATP
The correct answers are:
A) Pyruvate
B) 2 ATP
C) $2 \mathrm{NADH}$
During glycolysis, glucose, a six-carbon molecule, is metabolically broken down into two molecules of pyruvate, which each contain three carbons. This process occurs in the cytoplasm of cells. The chemical equation for glycolysis can be represented as: $$ \mathrm{C}{6} \mathrm{H}{12} \mathrm{O}_{6} + 2 \mathrm{NAD}^{+} + 2 \mathrm{ADP} + 2 \mathrm{P}_i \rightarrow 2 \text{ Pyruvate} + 2 \mathrm{ATP} + 2 \mathrm{NADH} + 2 \mathrm{H}^{+} $$ This transformation results in the production of 2 ATP and 2 NADH, which are crucial energy-carrying molecules utilized by the cells. The process described here is known as glycolysis.
Therefore, the end products of glycolysis in the cytoplasm are pyruvate, 2 ATP, and 2 NADH, corresponding to options A, B, and C respectively.
The end products of digested proteins are:
A) fatty acids
B) glycerol
C) glucose
D) amino acids
Solution:The correct option is D) amino acids.
Amino acids are the fundamental components of proteins. Proteins are complex molecules composed of one or more chains of amino acids. Therefore, when proteins are digested, they are broken down into their constituent smaller units, namely amino acids. There are twenty different types of amino acids that combine in various sequences to form proteins.
Fungi use mode of nutrition.
Fungi employ a unique mode of nutrition known as saprotrophic nutrition. In this process, they secrete digestive enzymes onto dead and decaying organic matter, breaking it down into simpler, soluble substances. Subsequently, fungi absorb these nutrients directly from their environment. This type of ingestion, where nutrients are absorbed in a solution form from decomposed matter, typifies the saprotrophic method.
Given below is a square of letters in which different words related to respiration in organisms are hidden. These words may be present in any direction - upwards, downwards, or along the diagonals. Find the words for your respiratory system. Clues about those words are given below the square.
(i) The air tubes of insects
(ii) Skeletal structures surrounding chest cavity
(iii) Muscular floor of chest cavity
(iv) Tiny pores on the surface of leaf
(v) Small openings on the sides of the body of an insect
(vi) The respiratory organs of human beings
(vii) The openings through which we inhale
(viii) An anaerobic organism
(ix) An organism with tracheal system
Growth that is accompanied by metabolic processes which spend energy involves:
A. Anabolism
B. Catabolism
C. Both A and B
D. None of these
The correct answer is: C. Both A and B
Growth in organisms is achieved through various metabolic activities, which include anabolism and catabolism. Anabolism is involved in the synthesis of complex molecules from simpler ones, a process that consumes energy. On the other hand, catabolism is the breakdown of complex molecules into simpler ones, releasing energy. Therefore, growth is facilitated by both these metabolic processes as they provide the necessary energy and building blocks.
💡 Have more questions?
Ask Chatterbot AINotes - Life Processes | Class 10 NCERT | Science
Comprehensive Life Processes Class 10 Notes: Simplify Your Biology Studies
Introduction to Life Processes
What are Life Processes?
Life processes are essential biological functions that enable living organisms to maintain life. These processes include growth, reproduction, nutrient assimilation, respiration, transportation of substances, and excretion. Understanding life processes is crucial for Class 10 students as it forms the foundation for advanced studies in biology.
Importance of Studying Life Processes in Class 10
Studying life processes helps in understanding the organization and function of living organisms. It allows students to appreciate the complexity of life and prepares them for further studies in biological sciences.
Characteristics of Living Beings
How Do We Identify Living Organisms?
Living organisms exhibit certain characteristics that differentiate them from non-living things. These include growth, reproduction, response to stimuli, metabolism, and cellular organization.
Movement as an Indicator of Life
Movement is a common indicator of life. Whether it's the beating of a heart, the movement of leaves towards sunlight, or the locomotion of animals, movement signifies living activities.
Nutrition
Understanding Nutrition
What is Nutrition?
Nutrition is the process of intake and utilization of food and nutrients by an organism. It is the fundamental life process that provides energy and materials for growth, repair, and maintenance.
Types of Nutrition: Autotrophic and Heterotrophic
Autotrophic Nutrition and Photosynthesis Autotrophs, such as green plants, synthesize their food through a process called photosynthesis. This process uses carbon dioxide, water, chlorophyll, and sunlight to produce glucose and oxygen.
Steps Involved in Photosynthesis:
- Absorption of light energy by chlorophyll
- Conversion of light energy to chemical energy
- Splitting of water molecules into hydrogen and oxygen
- Reduction of carbon dioxide to carbohydrates
Heterotrophic Nutrition Heterotrophs obtain their food by consuming other organisms. This type of nutrition is seen in animals, fungi, and some bacteria. For example, humans, lions, and fungi all rely on other organisms for their food source.
Nutrition in Human Beings The human digestive system is designed to process and absorb nutrients from food. The alimentary canal extends from the mouth to the anus and involves various stages of digestion and nutrient absorption.
Alimentary Canal and Digestive System:
- Mouth
- Esophagus
- Stomach
- Small intestine
- Large intestine
Each part plays a unique role in breaking down food and absorbing nutrients.
Respiration
Respiration Process
What is Respiration?
Respiration is the process by which organisms break down glucose to release energy. This process occurs in every cell and is essential for all life processes.
Types of Respiration: Aerobic and Anaerobic
Aerobic Respiration and Its Advantages Aerobic respiration takes place in the presence of oxygen and produces a large amount of energy. It involves the breakdown of glucose into carbon dioxide and water.
Anaerobic Respiration and Fermentation Anaerobic respiration occurs in the absence of oxygen. It produces less energy and results in by-products like lactic acid or ethanol, depending on the organism.
Human Respiratory System The human respiratory system includes various organs and structures that facilitate the exchange of gases.
Structure and Function of the Human Respiratory System:
- Nose
- Pharynx
- Larynx
- Trachea
- Bronchi
- Lungs
Gas Exchange Mechanism in Humans Oxygen is absorbed in the alveoli of the lungs and transported by red blood cells to different parts of the body. Carbon dioxide, a waste product, is expelled during exhalation.
Transportation
Transportation in Animals and Plants
Circulatory System in Humans
Components of the Circulatory System:
- Heart
- Blood
- Blood Vessels
The circulatory system ensures the distribution of oxygen, nutrients, and the removal of waste products.
Transportation in Plants
Xylem and Phloem Plants have specialized tissues for transportation. Xylem transports water and minerals from roots to leaves, while phloem distributes the products of photosynthesis.
Excretion
Excretion Process
Importance of Excretion
Excretion is the biological process of removing waste products from the body. This process is vital for maintaining homeostasis and ensuring the smooth functioning of the body.
Excretion in Human Beings
The human excretory system includes kidneys, ureters, bladder, and urethra. The kidneys filter blood to remove nitrogenous wastes, forming urine, which is then expelled from the body.
Structure of the Human Excretory System
The nephron is the functional unit of the kidneys, responsible for filtering blood and producing urine.
Function of Nephrons and Urine Formation:
- Filtration
- Reabsorption
- Secretion
Excretion in Plants
Plants excrete waste products through mechanisms like transpiration and storing waste in vacuoles or leaves that eventually fall off.
Conclusion
Summary of Key Points
Understanding the various life processes is crucial for comprehending how living organisms sustain life. From nutrition and respiration to transportation and excretion, each process plays a vital role in the maintenance and growth of living beings.
Importance of Understanding Life Processes for Exams
Grasping these concepts equips students with a solid foundation in biology, which is essential for performing well in exams and pursuing higher education in the biological sciences.
Additional Resources
Recommended Books and Websites
For further reading, consult your Class 10 biology textbook and explore educational websites like Khan Academy and BBC Bitesize for interactive resources.
Interactive Activities and Experiments
Engage in practical activities and experiments recommended in your curriculum to deepen your understanding of life processes.
By systematically studying and understanding these life processes, Class 10 students can excel in their biology exams and build a strong foundation for advanced studies.
🚀 Learn more about Notes with Chatterbot AI