Life Processes class 10 pdf

   Life Processes 

 Topics covered in this chapter are:

•  Introduction to Life Processes 

• Nutrition: Autotrophic and Heterotrophic

•  Nutrition Nutrition in Human Being:

• Digestive System, Digestion Process, Absorption, and Assimilation

• Respiration: Aerobic and Anaerobic Respiration, Respiratory System in Humans

•  Transportation: Circulatory System in Humans, Lymphatic System

•  Excretion: Excretory System in Humans, Urine Formation and Osmoregulation

•  Control and Coordination: Nervous System, Reflex Action, Endocrine System, Hormones and their Functions 

• Reproduction: Asexual and Sexual Reproduction, Human Reproductive System, Menstrual Cycle and Fertilization.

Nutrition 

 Nutrition is the science of how food affects the body, including the process of ingestion, digestion, absorption, metabolism, and elimination of nutrients. It encompasses all aspects of food and its role in promoting and maintaining health, as well as preventing and treating disease. Nutrition also includes the study of the chemical composition of food, the energy and nutrient content of food, and the dietary requirements of individuals at different stages of life. A balanced and healthy diet is essential for maintaining optimal health and preventing chronic diseases.

 Nutrition: autotrophic and heterotrophic

   Nutrition can be broadly categorized into two types: autotrophic and heterotrophic.

Autotrophic 

 Autotrophic nutrition refers to the ability of an organism to produce its own food from inorganic substances such as carbon dioxide, water, and sunlight. 

Examples of autotrophic organisms include plants, algae, and some bacteria. They are able to synthesize their own food from inorganic substances such as carbon dioxide, water, and sunlight. 

Heterotrophic 

 Heterotrophic nutrition, on the other hand, refers to the dependence of an organism on organic compounds produced by other organisms. 

Examples of heterotrophic organisms include animals, fungi, and some bacteria. They are unable to produce their own food and must obtain nutrients and energy from external sources. Animals, for instance, consume plants or other animals, while fungi feed on dead organic matter such as fallen leaves, logs, and animal carcasses.

 In summary, autotrophic nutrition involves the ability to produce one's own food, while heterotrophic nutrition involves the dependence on external sources of food.

 Nutrition in human beings 

 Nutrition is the process by which organisms obtain energy and nutrients for growth, repair, and maintenance of their bodies. In human beings, nutrition is essential for maintaining health and preventing diseases. 

•  There are six essential nutrients that human beings need to consume in their diet: 

•  Carbohydrates: These are the primary source of energy for the body. They are found in foods such as bread, pasta, rice, and fruits.

•  Proteins: These are important for building and repairing tissues in the body. They are found in foods such as meat, fish, beans, and eggs.

•  Fats: These are a concentrated source of energy and are essential for the absorption of certain vitamins. They are found in foods such as butter, oil, and nuts.

•  Vitamins: These are organic compounds that the body needs in small amounts for various metabolic processes. They are found in foods such as fruits, vegetables, and dairy products. 

•  Minerals: These are inorganic compounds that are essential for various metabolic processes. They are found in foods such as meat, dairy products, and vegetables. 

•  Water: This is essential for the proper functioning of the body and is needed for various metabolic processes.

•  The human digestive system breaks down the food into its constituent nutrients, which are then absorbed by the body. The digestive system consists of the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus.

•  After ingestion, food is broken down in the mouth by the action of enzymes in saliva. The food then passes down the esophagus into the stomach where it is further broken down by stomach acids and enzymes. The partially digested food then enters the small intestine where nutrients are absorbed into the bloodstream. The remaining waste material is then passed into the large intestine where water is absorbed and feces are formed. The feces are then eliminated through the rectum and anus.

•  A balanced diet that includes all the essential nutrients in the right proportions is essential for maintaining good health. It is important to consume a variety of foods to ensure that all the essential nutrients are obtained in sufficient amounts.

Digestive System, Digestion Process, Absorption, and Assimilation 

 The digestive system is the set of organs and glands that are responsible for breaking down food into smaller molecules that can be absorbed and used by the body. The digestive system includes the mouth, esophagus, stomach, small intestine, large intestine, pancreas, liver, and gallbladder.

•  The digestion process begins in the mouth, where food is broken down into smaller pieces by the teeth and mixed with saliva, which contains enzymes that help break down carbohydrates. The food then travels down the esophagus to the stomach, where it is mixed with stomach acid and enzymes that break down proteins. The mixture of food and digestive juices in the stomach is called chyme. 

•  From the stomach, chyme moves into the small intestine, where further digestion and absorption of nutrients take place. The small intestine is where most of the nutrients from food are absorbed into the bloodstream. The small intestine has a large surface area that is lined with villi and microvilli, which are tiny finger-like projections that increase the surface area available for absorption.

•  After the nutrients are absorbed, they are transported to the liver, where they are processed and either stored or sent to the bloodstream to be used by the body. The large intestine then absorbs water and electrolytes from the remaining material, forming solid feces, which are eliminated through the rectum and anus. 

 Assimilation

Assimilation is the process by which the absorbed nutrients are used by the body's cells for energy, growth, and repair. Once the nutrients are in the bloodstream, they are transported to cells throughout the body, where they are used for various metabolic processes.

 Respiration: Aerobic and Anaerobic Respiration, Respiratory System in Humans

Respiration 

  Respiration is the process by which living organisms produce energy in the form of ATP (Adenosine Triphosphate) by breaking down complex organic molecules such as glucose. There are two types of respiration: aerobic respiration and anaerobic respiration.

Aerobic respiration

 Aerobic respiration is the process of breaking down glucose in the presence of oxygen to produce energy. This process occurs in the mitochondria of the cell and involves the complete breakdown of glucose into carbon dioxide and water. The overall reaction can be summarized as:

 C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy(ATP)

 

Anaerobic respiration

Anaerobic respiration, on the other hand, is the process of breaking down glucose in the absence of oxygen. This process occurs in the cytoplasm of the cell and involves the partial breakdown of glucose. The overall reaction can be summarized as: 

 C6H12O6 → 2C3H6O3 + Energy (ATP) 

•  In humans, the respiratory system is responsible for the exchange of gases between the body and the environment. The respiratory system consists of the lungs, trachea, bronchi, bronchioles, and alveoli. When we inhale, air enters the body through the nose or mouth and travels down the trachea and into the lungs. The lungs are made up of millions of tiny air sacs called alveoli, which are surrounded by blood vessels.

•  Oxygen from the air we breathe diffuses across the walls of the alveoli and into the bloodstream, where it is carried to the cells of the body. At the same time, carbon dioxide, which is a waste product of cellular respiration, diffuses from the cells into the bloodstream and is carried back to the lungs. When we exhale, carbon dioxide is released from the body as we breathe out.

 In summary, respiration is the process by which living organisms produce energy, either through aerobic or anaerobic respiration. The respiratory system in humans is responsible for the exchange of gases between the body and the environment, allowing for the uptake of oxygen and the release of carbon dioxide.

Class 10 science series wise all chapter notes pdf available 

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Circulatory System in Humans, Lymphatic System

•    The circulatory system and the lymphatic system are two interconnected systems in the human body that play important roles in transporting fluids, nutrients, and waste throughout the body. 

•  The circulatory system, also known as the cardiovascular system, consists of the heart, blood vessels, and blood. Its main function is to transport oxygen and nutrients to the body's tissues and organs and to remove carbon dioxide and other waste products from them. 

•  The heart is the main organ of the circulatory system and is responsible for pumping blood throughout the body. The blood vessels include arteries, veins, and capillaries, which carry blood to and from the heart and throughout the body's tissues.

•  The lymphatic system is a network of vessels, tissues, and organs that work together to maintain the body's fluid balance and fight infection. The lymphatic system is closely linked to the circulatory system, and both systems work together to transport fluids and immune cells throughout the body.

•  The lymphatic system consists of lymphatic vessels, lymph nodes, the spleen, and the thymus gland. Lymphatic vessels are similar to blood vessels but carry a fluid called lymph instead of blood. Lymph nodes are small, bean-shaped structures that filter lymph and trap foreign particles, such as bacteria and viruses. The spleen and the thymus gland are also involved in the immune system and help to produce and store immune cells.

 In summary, the circulatory system and lymphatic system are both vital to the proper functioning of the human body. While the circulatory system is responsible for transporting oxygen and nutrients to the body's tissues and organs, the lymphatic system is responsible for maintaining the body's fluid balance and fighting infection. Together, these two systems work to keep the body healthy and functioning properly.

Excretory System in Humans, Urine Formation and Osmoregulation 

 The excretory system in humans is responsible for removing waste products and excess water from the body. The major organs involved in this process include the kidneys, ureters, bladder, and urethra.

•  Urine formation occurs in the kidneys, which are two bean-shaped organs located on either side of the spine in the lower back. The kidneys receive blood from the renal arteries and filter out waste products and excess water to produce urine. The urine then flows down the ureters, which are tubes that connect the kidneys to the bladder. 

•  The bladder is a muscular sac that stores urine until it is eliminated from the body through the urethra, which is a tube that connects the bladder to the outside of the body.

Osmoregulation

 Osmoregulation is the process by which the body maintains the balance of water and electrolytes in the blood and tissues. This is important for maintaining proper hydration levels and electrolyte balance, which are necessary for normal body function. 

•  The kidneys play a critical role in osmoregulation by regulating the concentration of electrolytes, such as sodium and potassium, in the blood. This is achieved through a complex process that involves the reabsorption of electrolytes and water from the urine as it passes through the kidneys.

•  In addition to electrolyte regulation, the kidneys also play a role in regulating blood pressure through the renin-angiotensin-aldosterone system (RAAS). This system regulates the amount of fluid in the body and plays a key role in maintaining blood pressure.

• Overall, the excretory system is a complex system that plays a vital role in maintaining homeostasis and keeping the body functioning properly.

Nervous System, Reflex Action, Endocrine System, Hormones and their Functions

   The nervous system and the endocrine system are the two main systems responsible for control and coordination in the body. 

•  The nervous system is composed of the brain, spinal cord, and nerves. It is responsible for the transmission of signals between different parts of the body and for the coordination of body functions. The nervous system can be divided into two parts: the central nervous system (CNS) and the peripheral nervous system (PNS). 

•  The CNS consists of the brain and spinal cord and is responsible for processing and integrating sensory information and coordinating motor responses. The PNS consists of all the nerves that connect the CNS to the rest of the body and is responsible for transmitting signals to and from the CNS.

•  Reflex actions are automatic, rapid, and involuntary responses to a stimulus. They occur without conscious thought or decision-making and are controlled by the spinal cord rather than the brain. Examples of reflex actions include the knee-jerk reflex and the withdrawal reflex. 

•  The endocrine system is a network of glands that secrete hormones into the bloodstream. Hormones are chemical messengers that travel through the bloodstream and affect the activity of target cells or organs. Hormones play a crucial role in regulating many bodily functions, including growth and development, metabolism, and reproduction. 

•  Some of the major glands of the endocrine system include the pituitary gland, thyroid gland, adrenal glands, and pancreas. The pituitary gland is often called the "master gland" because it produces hormones that control the activity of other glands in the endocrine system. The thyroid gland produces hormones that regulate metabolism, while the adrenal glands produce hormones that help the body respond to stress.

 Overall, the nervous system and the endocrine system work together to regulate and coordinate the functions of the body. While the nervous system controls rapid responses to stimuli, the endocrine system controls slower, longer-lasting responses. Together, they help to maintain homeostasis and keep the body functioning properly.

 Reproduction: Asexual and Sexual Reproduction, Human Reproductive System, Menstrual Cycle and Fertilization

  Reproduction is the biological process by which new individuals of a species are produced. In animals, including humans, there are two main types of reproduction: asexual reproduction and sexual reproduction. 

Asexual reproduction

 Asexual reproduction is a type of reproduction that involves only one parent, and offspring are genetically identical to the parent. This type of reproduction is common in single-celled organisms like bacteria and some types of fungi. In higher animals, asexual reproduction is rare, but it can occur in some species of insects, fish, and reptiles.

 Sexual reproduction

Sexual reproduction involves the fusion of gametes (reproductive cells) from two different parents, resulting in genetically diverse offspring. In humans, sexual reproduction occurs through the joining of an egg (ovum) and a sperm (spermatozoon) during fertilization. 

•  The human reproductive system consists of the gonads (testes in males and ovaries in females), the ducts that transport gametes (the vas deferens and the fallopian tubes), and the accessory glands and structures (such as the prostate gland, seminal vesicles, and uterus) that support the development and delivery of gametes.

•  In females, the menstrual cycle is a regular physiological process that prepares the body for pregnancy. The cycle is regulated by hormones, and it involves the release of an egg from the ovary (ovulation) and the thickening of the uterine lining to support implantation of a fertilized egg. If fertilization does not occur, the uterine lining is shed during menstruation. 

•  In males, sperm are produced in the testes and mature in the epididymis. During ejaculation, sperm are transported through the vas deferens and mixed with seminal fluid from the accessory glands to form semen. Semen is then ejaculated from the penis during sexual intercourse.

 Fertilization

Fertilization occurs when a sperm cell and an egg cell fuse to form a zygote. The zygote contains genetic material from both parents and will develop into an embryo, which will eventually become a fetus. Fertilization typically occurs in the fallopian tube, and the resulting embryo travels to the uterus for implantation and further development.