CBSE Class 10 Science • Life Processes • Notes and Mind Map
Life Processes Class 10 Notes and Mind Map
Every living cell needs materials, usable energy and a way to remove waste. These Life Processes Class 10 notes explain how nutrition, respiration, transportation and excretion work together to meet those needs. Use the mind map to connect the processes and recall their important stages.
Read this chapter by following the journey of materials: food enters or is produced, nutrients become available, cells release energy, transport systems move substances, and metabolic wastes leave the organism. This connected approach makes organ functions easier to understand.
Life Processes Class 10 Summary: One Connected System
| Process | What it provides | Connection with other processes |
|---|---|---|
| Nutrition | Materials for growth, repair and energy release. | Nutrients supply substrates for respiration. |
| Respiration | Usable energy for cellular activities. | Energy supports transport and maintenance. |
| Transportation | Movement of nutrients, gases and wastes. | Connects exchange surfaces with internal cells. |
| Excretion | Removal of metabolic wastes. | Transport brings wastes to excretory organs. |
Nutrition in Plants: Making Organic Food
Green plants use light energy to make carbohydrates from carbon dioxide and water. Chlorophyll captures light, roots supply water, and stomata allow gaseous exchange. Photosynthesis links the plant’s nutrition with its transport system.
Overall Photosynthesis Equation
6CO2 + 6H2O → C6H12O6 + 6O2
Requirements: Light and chlorophyll.
This is a simplified overall equation. The process involves several stages rather than one direct collision between the written reactants.
Stomata and Guard Cells
Stomata are pores surrounded by guard cells. Changes in guard-cell turgor control pore opening and closing. Open stomata permit carbon dioxide entry but also allow water vapour to escape.
Human Nutrition: Digestion, Absorption and Assimilation
Digestion breaks large food molecules into smaller absorbable substances. Absorption transfers digested nutrients across the intestinal lining. Assimilation is their use by cells for energy, growth, repair or storage.
| Region | Main event | Why it matters |
|---|---|---|
| Mouth | Chewing and the start of starch digestion by salivary amylase. | Smaller pieces provide more surface for enzyme action. |
| Oesophagus | Peristalsis moves food towards the stomach. | Muscular movement transports food. |
| Stomach | Acidic conditions support pepsin action on proteins. | Mucus helps protect the stomach lining. |
| Small intestine | Digestion is completed and most nutrients are absorbed. | Villi provide a large exchange surface. |
| Large intestine | Further water absorption and formation of faeces. | Undigested material is prepared for removal. |
Accessory Organs Help Without Food Passing Through Them
The liver supplies bile and the pancreas supplies digestive enzymes. Food travels through the alimentary canal, while these organs deliver secretions into it.
Respiration: From Glucose to Usable Energy
Cells release energy through the breakdown of food. ATP acts as an immediate energy carrier for many cellular activities. Breathing supports this process in humans by bringing air into the lungs and removing it.
The Common Starting Stage
Glucose first breaks down into pyruvate in the cytoplasm. What happens next depends on the organism and oxygen availability.
| Conditions | Further products | Example |
|---|---|---|
| Oxygen available | Carbon dioxide, water and a larger usable energy yield. | Aerobic respiration involving mitochondria. |
| Without oxygen in yeast | Ethanol, carbon dioxide and a smaller energy yield. | Alcoholic fermentation. |
| Insufficient oxygen supply in working muscles | Lactic acid and a smaller energy yield. | Lactic-acid formation. |
Breathing and Gas Exchange
During inhalation, the diaphragm contracts and the chest cavity expands. Air enters the lungs. At the alveoli, oxygen diffuses into blood and carbon dioxide diffuses towards the air.
Alveoli and intestinal villi share an important design principle: a large surface area supports efficient exchange. Thin barriers and transport connections also help maintain movement of substances.
Transportation in Humans
Blood connects organs with cells throughout the body. Red blood cells carry oxygen mainly through haemoglobin, plasma transports dissolved substances, white blood cells participate in defence, and platelets contribute to clotting.
Heart, Vessels and Double Circulation
Pulmonary circulation carries blood between the heart and lungs. Systemic circulation carries it between the heart and the rest of the body. Separation of the two pathways supports efficient oxygen delivery.
Arteries: carry blood away from the heart.
Veins: carry blood towards the heart.
Capillaries: provide thin exchange surfaces.
Direction defines arteries and veins. Oxygen content alone does not: pulmonary arteries carry deoxygenated blood and pulmonary veins carry oxygenated blood.
Lymph
Lymph returns excess tissue fluid towards the circulation. It also transports absorbed fats from the intestine and contributes to immune functions.
Transportation in Plants
Plants require two different transport networks. Xylem carries water and mineral ions. Phloem transports soluble products of photosynthesis from sources to sinks where they are used or stored.
Transpiration Pull
Evaporation from leaves helps create a pull on the water column in xylem. This supports upward water movement. Root pressure can also contribute under suitable conditions.
Translocation
Loading and unloading sugars in phloem involves energy-dependent processes. Water movement generates pressure differences that drive transport. The direction depends on source and sink locations, so food movement is not restricted to downwards.
Excretion in Humans: Filtration with Recovery
Kidney function involves more than filtering waste. Nephrons filter blood plasma and then selectively recover useful substances and much of the water. Tubular secretion adds certain substances to the filtrate.
Follow the Fluid Through a Nephron
- Filtration occurs across the glomerulus into Bowman’s capsule.
- Useful substances and water are selectively reabsorbed along the tubule.
- Secretion moves additional substances into the tubular fluid.
- The remaining fluid contributes to urine.
Ureters carry urine to the bladder. The urethra carries it out of the body.
Excretion in Plants
Plants can release gases through diffusion, store some wastes in tissues that are later shed, and accumulate substances such as resins and gums. Different waste products follow different routes.
How to Use the Life Processes Mind Map
Use the four main branches as a connected revision route. At each branch, recall the input, main structures, process and output. Then explain how it supports another life process.
- Nutrition: connect food production or intake with digestion and absorption.
- Respiration: connect glucose breakdown with energy availability.
- Transportation: follow materials between exchange surfaces and cells.
- Excretion: distinguish waste removal from recovery of useful substances.
Revise diagrams alongside the map. Trace the path of food, air, blood or filtrate rather than memorising labels without their functions.
Frequently Asked Questions
Why do living organisms need maintenance processes even while resting?
Cells continue to repair structures, regulate internal conditions and use energy. Visible movement is not required for these activities to continue.
Why cannot diffusion alone supply a large multicellular body?
Many cells lie far from the body surface. Diffusion over those distances is too slow to meet their demands, making organised transport necessary.
How is assimilation different from absorption?
Absorption transfers nutrients across the digestive lining. Assimilation is their subsequent use by cells.
Does food travel through the liver and pancreas?
No. These organs provide secretions to the digestive tract. Food remains within the alimentary canal.
Why does aerobic respiration yield more usable energy than fermentation?
It breaks down glucose more completely. Fermentation leaves considerable chemical energy in products such as ethanol or lactic acid.
Why are oxygenated and deoxygenated blood kept separate in mammals?
Separation supports efficient oxygen delivery and high rates of respiration. This helps meet demands associated with activity and temperature regulation.
Why is phloem transport not always downwards?
Sugars move from sources to sinks. A sink can be above or below the source, depending on growth and storage requirements.
Is urine simply the fluid initially filtered from blood?
No. Reabsorption and secretion change the filtrate as it passes through the nephron. Urine is the remaining fluid after this processing.
Why are blood cells normally absent from glomerular filtrate?
The normal filtration barrier retains blood cells and most large proteins while allowing water and smaller dissolved substances through.
What is dialysis in the context of this chapter?
Dialysis is a treatment that removes wastes and excess substances from blood when kidney function is inadequate. It illustrates exchange across a selectively permeable membrane.
How can I remember the chapter without memorising long paragraphs?
Follow each material’s journey and explain the function of every major structure. Use the mind map to recall sequences, then check the detailed notes.
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