All plants and animals that are alive on this planet living things. The deciding factor for categorizing something as living is movement. Movement in animals is fast and can be observed easily, as compared to the movement in plants, which is slow and observed with difficulty.
Animals can move from one place to another or they can move their body parts. However, plants can only move parts of their body, such as leaves, flowers, roots, and shoots. Find out more about how living organisms evolved with Superprof's notes on evolution and heredity.
Features of Life Processes
Earth is the only known planet that can sustain life. The living beings on Earth live, die, and become part of nature again. Living organisms can be differentiated from inanimate entities on various parameters of life processes.
Definition: All the processes, such as respiration, nutrition, circulation, excretion, etc., that are necessary for the survival of the living organisms are known as life processes.
The distinct features of life processes are:
- The maintenance of living organisms is essential even if they are moving, resting, or sleeping.
- Nutrition, respiration, circulation, excretion are examples of essential life processes.
- In unicellular organisms, life processes are carried out by a single cell.
- In multicellular organisms, life processes are carried out by complex and well-developed systems.
With these points in mind, let us take a deep dive into the Class 10 Biology chapter on life processes. You can also check out detailed revision notes on human reproduction.
Nutrition is the process by which an organism takes in food and utilizes it to obtain energy for growth, repair, and maintenance. Organisms require this energy to perform various activities throughout life. The energy is derived from the nutrients which are obtained during nutrition.
Modes of Nutrition
- Autotrophic Nutrition: The mode of nutrition in which an organism prepares its own food. Examples: Green plants and blue-green algae follow the autotrophic mode of nutrition.
- Heterotrophic Nutrition: The mode of nutrition in which an organism obtains its food from another organism. Examples: Most bacteria, fungi, and all animals, including humans, follow the heterotrophic mode of nutrition.
Heterotrophic nutrition is of 3 types.
- Saprophytic nutrition in which organisms feed on dead and decaying matter. Example: Fungi.
- Parasitic nutrition in which organisms feed on their living host. Example: Cuscuta.
- Holozoic nutrition in which an organism takes in whole food and breaks it inside its body. Example: Amoeba.
Photosynthesis is a process in which carbon dioxide and water are utilized by plants, in the presence of sunlight and chlorophyll, to synthesize carbohydrates like glucose.
The green leaves of plants are the main site of photosynthesis. They contain a green pigment known as chlorophyll that traps sunlight for photosynthesis.
Occurrence of Photosynthesis
- Absorption of light energy by chlorophyll
- Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen
- Reduction of carbon dioxide by hydrogen to produce carbohydrates (glucose)
Find out why the study of Biology is vital to our understanding of our planet.
Stomata are the tiny pores present on the surface of leaves. They facilitate gaseous exchange in the leaves for the purpose of photosynthesis.
The opening and closing of the stomatal pores are controlled by the guard cells. The guard cells swell when water flows into them, causing the stomatal pore to open. Similarly, the pore closes if the guard cells shrink.
Nutrition in Human Beings
The human body consists of an alimentary canal and some accessory glands. The alimentary canal is divided into several parts, namely:
- Oesophagus/food pipe
- Small intestine
- Large intestine
The salivary gland, liver, and pancreas are accessory glands that lie outside the alimentary canal.
Respiration is a metabolic process that involves the breakdown of food to release energy. The process may take place in different conditions like the presence or absence of oxygen, or limited availability of oxygen. The first step in all 3 cases is the breakdown of glucose into a 3-carbon molecule called pyruvate. This process takes place in the cytoplasm.
Types of Respiration
- Anaerobic respiration: The breakdown of pyruvate into ethanol and carbon dioxide in the absence of oxygen is known as anaerobic respiration. It is also known as fermentation.
- Aerobic respiration: The breakdown of pyruvate into carbon dioxide and water in the presence of oxygen is known as aerobic respiration.
The energy released during the process of respiration is used up to synthesize the ATP (adenosine triphosphate) which is used to fuel all other activities in the cell.
Improve your own digestive health by learning more about the human digestive system!
Human Respiratory System
The human respiratory system consists of the nose, nasal cavities, pharynx, larynx, trachea/windpipe, bronchi, bronchioles, and alveoli.
- Air is taken into the body through the nostrils.
- The air passing through the nostrils is filtered by fine hairs that line the passage.
- From here, the air passes through the throat and into the lungs.
- Within the lungs, the passage divides into smaller and smaller tubes which finally terminate in balloon-like structures called alveoli.
- The walls of the alveoli contain an extensive network of blood vessels where the exchange of gases takes place.
Respiration in Plants
Plants contain stomata (present in leaves) and lenticels (present in stems) which facilitate the exchange of gases.
Transportation in Humans
Transportation in humans is carried out by the circulatory system. It is responsible for the supply of oxygen, nutrients, removal of carbon dioxide, and other excretory products.
The human circulatory system in humans mainly consists of:
- Blood: Consists of a fluid medium called plasma in which the cells are suspended. Plasma transports food, carbon dioxide, and nitrogenous waste in dissolved form. Red blood cells carry oxygen throughout the body.
- Heart: Is the main pumping organ of the body which is composed of cardiac muscles.
- The heart is divided into 4 chambers that are involved in the transportation of oxygenated and deoxygenated blood.
- The upper 2 chambers are called atria and the lower 2 chambers are called ventricles.
- The contraction of cardiac muscles is called systole.
- The relaxation of cardiac muscles is called diastole.
- Blood Vessels: Carry blood throughout the human body. There are 3 types of blood vessels:
- Arteries carry oxygenated blood.
- Veins carry deoxygenated blood.
- Capillaries are the site of gaseous exchange between blood and cells.
In the human heart, blood passes through the heart twice in one cardiac cycle. This type of circulation is called double circulation. Double circulation ensures the complete segregation of oxygenated and deoxygenated blood. This segregation is vital for optimum energy production in warm-blooded animals.
Transportation in Plants
Plants have specialized vascular tissues for the transportation of water and minerals. These tissues are of 2 types.
- Xylem is responsible for the transportation of water and minerals from the roots to the different parts of the plant. Xylem tissue consists of vessels and tracheids.
- Phloem is responsible for the transportation of food from the leaves to different parts of the plants.
Excretion is the biological process involved in the removal of harmful metabolic waste from the body.
Learn how genetics and heredity influence human traits with Superprof's revision notes on Class 10 ICSE Genetics.
Excretion in Human Beings
The excretory system of humans consists of a pair of kidneys, a pair of ureters, urinary bladder, and urethra. The process of excretion is as follows:
- Urine produced in the kidneys passes through the ureters and gets collected in the urinary bladder from where it is expelled through the urethra.
- Nephrons are the basic filtration unit of the kidneys.
- Each nephron consists of 2 parts- glomerulus and renal tubule.
- The glomerulus consists of a bunch of capillaries.
- Blood enters the kidney through the afferent arteriole and filtered blood leaves the glomerulus through the efferent arteriole.
- The renal tubule starts with a cup-like structure called Bowman’s capsule that encloses the glomerulus.
- Capillaries of kidneys filter the blood and the essential substances like glucose, amino acids, salts, and the required amount of water are reabsorbed.
- The amount of water reabsorbed depends on how much water there is in the body.
- Excess water and nitrogenous waste in humans are converted to urine.
- The urine, thus produced, is passed to the urinary bladder via the ureters.
- The ureter is a tube emerging from the median surface of each kidney. It connects the kidney to the urinary bladder.
- The urinary bladder is a muscular bag that is meant for the temporary storage of urine. It connects to the urethra from where urine is discharged.
Excretion in Plants
- Carbon dioxide, excess water, and nitrogenous compounds are the major excretory products in plants.
- Excretion of gaseous waste in plants takes place through stomatal pores on leaves.
- Oxygen, released during photosynthesis, is used for respiration, while carbon dioxide, released during respiration, is used for photosynthesis.
- Excess water is excreted by transpiration.
- Waste products may be stored in leaves that fall off.
- Other waste products are stored as resins and gums, especially in old xylem.
- Plants also excrete some waste substances into the soil around them.
Kidney failure results in a lot of complications. To compensate for this situation, a technology called dialysis has been developed. Dialysis makes use of a machine filter called a dialyzer or artificial kidney. The dialyzer is used to remove excess water and salt, balance other electrolytes in the body, and remove the waste products of metabolism.
Blood from the body is removed and made to flow through a series of tubes consisting of a semipermeable membrane. A dialysate flows on the other side of the membrane, which draws impurities through the membrane.
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