Category: CBSE Class 7

On this page, you will find NCERT Class 7 Geography Chapter 6 Notes Pdf free download. CBSE Class 7 Social Science Notes Geography Chapter 6 SST Natural Vegetation and Wild Life will seemingly help them to revise the important concepts in less time.

Natural Vegetation and Wild Life Class 7 Notes Social Science Geography Chapter 6

CBSE Class 7 Geography Chapter 6 Notes Understanding The Lesson

1. As we go higher and higher places, we can see the changes in the landform and natural vegetation.

2. On the higher places we find tall trees with thin pointed leaves and cone-shaped canopies which are called coniferous trees on the mountain slopes.

3. With the change in height, the climate changes and that changes natural vegetation.

4. The growth of vegetation depends on temperature and moisture. It also depends on factors like slope and thickness of soil.

5. Natural vegetation is generally classified into three broad categories:

• Forests
• Grasslands and
• Shrubs.

6. Tropical Evergreen Forest is also called tropical rainforests. These are thick forests occurring in the regions near the equator and close to the tropics.

7. Tropical Evergreen Forests are found in the regions which are hot and receive heavy rainfall throughout the year. As there is no particular dry season, the trees do not shed their leaves. This is the reason they are called evergreen. These are dense and do not allow the sunlight even in the day time. Hardwood trees like rosewood, ebony, mahogany are common here.

8. Tropical Deciduous Forests are the monsoon forests which are found in the large part of India, northern Australia and in Central America.

9. These regions experience seasonal changes. Trees shed their leaves in the dry season to conserve water. Sal, teak, neem and shisham are trees found in these regions.

10. Temperate Evergreen Forests are located in the mid-latitudinal coastal region. These are found in south­east USA, South China and in South-east Brazil. They comprise both hard and softwood trees like oak, pine, eucalyptus etc .

11. Temperate Deciduous Forests are found in the north-eastern part of USA, China, New Zealand, Chile and also found in the coastal regions of Western Europe. These are found towards higher latitudes. The trees shed their leaves in the dry season. The common trees are oak, ash, beech, etc. Deer, foxes, wolves are the animals commonly found. Birds like pheasants, monals are also found here.

12. The west and south-west margins of the continents have Mediterranean vegetation. It is mostly found in the areas around the Mediterranean Sea in Europe, Africa and Asia. These regions are marked for hot dry summers and mild rainy winters. Citrus fruits such as oranges, figs, olives and grapes are commonly cultivated here.

13. Coniferous Forests are found in the higher latitudes of Northern hemisphere. These are also called as Taiga. The trees found here are tall, softwood evergreen trees. Silver fox, mink, polar bear are the common animals found here.

14. Tropical grasslands occur on either side of the equator and extend till the tropics. This vegetation grows in the areas of moderate to low amount of rainfall. The grass can grow very tall, about 3 to 4 metre in height. Savannah grasslands of Africa are of this type. Elephants, zebras, giraffes, deer, leopards are common in tropical grasslands.

15. Temperate grasslands are found in the mid-latitudinal zones and in the interior part of the continents. Wild buffaloes, bisons, antelopes are common in the temperate region.

16. Thorny bushes are found in the dry desert-like regions. These are located on the western margins of the continents.

Notes of Geography Class 7 Chapter 6 Important Terms

Forests: Where trees grow in plentiful.

Grassland: These are lands full of grasses.

Natural vegetation: These grow naturally.

Anaconda: A type of snake which is the largest snake found in the tropical rainforest.

On this page, you will find NCERT Class 7 Geography Chapter 5 Notes Pdf free download. CBSE Class 7 Social Science Notes Geography Chapter 5 SST Water will seemingly help them to revise the important concepts in less time.

Water Class 7 Notes Social Science Geography Chapter 5

CBSE Class 7 Geography Chapter 5 Notes Understanding The Lesson

1. The sun’s heat causes evaporation of water vapour. When the water vapour cools down, it condenses and forms clouds.

2. The process by which water continually changes its form and circulates between oceans, atmosphere and land is known as the water cycle.

3. The same water that existed centuries ago still exists today.

4. The major sources of fresh water are the rivers, ponds, springs and glaciers.

5. The water of the oceans is salty or saline as it contains large amount of dissolved salts. Ocean water is 97.3% of total water available on the earth.

6. A part of the earth surface is covered by water.

7. Ocean water keeps moving continuously, it is never still.

8. The movements that occur in oceans can be broadly categorized as: waves, tides and currents.

9. When the water on the surface of the ocean rises and falls alternately, they are called waves.

10. During a storm, the winds blowing at very high speed form huge waves.

11. An earthquake, a volcanic eruption or underwater landslides can shift large amounts of ocean water. This results in a huge tidal wave called tsunami, that may be as high as 15 m.

12. The rhythmic rise and fall of ocean water twice in a day is called a tide. When water covers much of the shore by rising to its highest level it is called high tide. It is low tide when water falls to its lowest level and recedes from the shore.

13. The strong gravitational pull exerted by the sun and the moon on the earth’s surface causes the tides.

14. During the full moon and new moon days, the sun, the moon and the earth are in the same line and the tides are the highest. These tides are called spring tides.

15. When the moon is in its first and last quarter, the ocean waters get drawn in diagonally opposite direction by the gravitational pull of sun and earth resulting in low tides. These tides are called neap tides.

16. Ocean currents are streams of water flowing constantly on the ocean surface in definite directions. The ocean currents may be warm or cold.

17. Generally the warm ocean currents originate near the equator and move towards the poles.

18. The cold currents carry water from polar or higher latitudes to tropical or lower latitudes.

19. The ocean current influence the temperature conditions of the area. Warm currents bring about warm temperature over land surface.

20. The areas where the warm and cold currents meet provide the best fishing grounds of world.

21. The areas where a warm and cold current meet also experience foggy weather making it difficult for navigation.

Notes of Geography Class 7 Chapter 5 Important Terms

Evaporation: A process through which water turns into vapour.

Tide: Rise and fall of ocean water.

Waves: Alternatively normal rise and fall of ocean water.

Tsunami: Huge tidal waves.

Ocean currents: Streams of water flowing constantly on the ocean surface in definite directions. Terrarium: An artificial enclosure for keeping small house plants.

On this page, you will find NCERT Class 7 Geography Chapter 4 Notes Pdf free download. CBSE Class 7 Social Science Notes Geography Chapter 4 SST Air will seemingly help them to revise the important concepts in less time.

Air Class 7 Notes Social Science Geography Chapter 4

CBSE Class 7 Geography Chapter 4 Notes Understanding The Lesson

1. All living beings depend on the atmosphere, use the air for breath and protect us from the harmful effects of the sun’s rays.

2. Air makes the temperature on the earth livable. Without this, during the day time we feel heat and get frozen during night.

3. The air which we breathe is mixture of many gases. The constituents of air are Nitrogen, Oxygen, Argon, Carbon dioxide mainly.

4. Apart from these gases, tiny dust particles are also present in the air.

5. Nitrogen is the most plentiful gas (78%) in the air. In the air, Oxygen, Argon and Carbon dioxide are 21%, 93% and 0.03% respectively.

6. Plants need nitrogen for their survival. They cannot take nitrogen directly from the air. Bacteria that live in the soil and roots of some plant take nitrogen from the air and change its form so that plants can use it.

7. Oxygen that is taken by human and animals as breathe is produced by plants during photosynthesis. In this way oxygen content in the air remains constant. If we cut trees then this balance gets disturbed.

8. Green plants use carbon dioxide to make their food and release oxygen. The amount of carbon dioxide released by humans or animals seems to be equal to the amount used by the plants which make a perfect balance. However, the balance is upset by burning of fuels.

9. Our atmosphere is divided into five layers starting from the earth’s surface.

10. The first layer is the Troposphere whose average height is 13 km.

11. The second layer is the Stratosphere which extends upto the height of 50 km.

12. The third layer is Mesosphere which extends upto the height 80 km.

13. The fourth layer is Thermosphere which extends upto height of 80 to 400km.

14. The fifth and uppermost layer is Exosphere. This layer has very thin air. Light gases like helium and hydrogen float into the space from here.

15. Weather is this hour-to-hour, day to day condition of the atmosphere. A hot or humid weather may make one irritable. A pleasant, breezy weather may make one cheerful and even plan for an outing.

16. The average weather condition of a place for a longer period of time represents the climate of a place.

17. The degree of hotness and coldness of the air is known as temperature. The temperature of the atmosphere changes between day and night and also season to season. Summers are hotter than winters.

18. An important factor that influences the distribution of temperature is insolation. The amount of insolation decreases from the equator towards the poles. Therefore, the temperature decreases in the same manner.

19. Air pressure is defined as the pressure exerted by the weight of air on the earth’s surface.

20. Horizontally, the distribution of air pressure is influenced by temperature of air at a given place. Wherever, pressure of air is low, the air is cold. Likewise, if pressure is high, the air becomes warmer.

21. The air always moves from high-pressure areas to low-pressure areas.

22. Winds can be broadly divided into three types: Permanent winds, Seasonal winds and Local winds.

23. Permanent winds blow constantly throughout the year in a particular direction.

24. Seasonal winds change their direction in different seasons.

25. Local winds blow only during a particular period of the day or year in a small area.

26. When water evaporates from land and different water bodies, it becomes water vapour. Moisture at any time is known as humidity.

27. When the water is full of water vapour we call it a humid day. On a humid day, clothes take longer to dry and sweat from our body does not evaporate easily.

Notes of Geography Class 7 Chapter 4 Important Terms

Atmosphere: Huge blanket of air which surrounds the earth.

Thermometer: An instrument used in measuring temperature.

Barometer: An instrument used in measuring air pressure.

Rain Gauge: An instrument used in measuring the amount of rainfall.

Humidity: Moisture in the air.

Moisture: Water vapour present in the atmosphere.

Temperature: The degree of hotness and coldness of the air.

Climate: The average weather condition of a place.

Global warming: Increased temperature of the earth.

On this page, you will find NCERT Class 7 Geography Chapter 3 Notes Pdf free download. CBSE Class 7 Social Science Notes Geography Chapter 3 SST Our Changing Earth will seemingly help them to revise the important concepts in less time.

Our Changing Earth Class 7 Notes Social Science Geography Chapter 3

CBSE Class 7 Geography Chapter 3 Notes Understanding The Lesson

1. The lithosphere is broken into a number of plates known as the Lithospheric plates.

2. Movement of the molten magma inside the earth occurs thereby the Lithospheric plates are moved very slowly just a few millimetres each year.

3. movement of these plates causes changes on the surface of the earth.

4. The forces that act in the interior of the earth are called endogenic forces, while the forces that work on the surface of the earth are called exogenic forces.

5. Endogenic forces sometimes produce sudden movements and at the other times produce slow movements. Sudden movements like earthquakes and volcanoes cause mass destruction over the surface of the earth.

6. A volcano is a vent (opening) in the earth’s crust through which molten material erupts suddenly.

7. Vibration in the surface of earth is called earthquakes. The place in the crust where the movement starts is called the focus and the place on the surface above the focus is called the epicentre.

8. Greatest damage is usually closest to the epicentre and the strength of the earthquake decreases away from the centre.

9. Although earthquake cannot be predicted but impact can be minimized. Recognizing safe spot, staying away from fire places, chimneys, windows etc., are the measures which may be helpful as safeguards.

10. The landscape is being continuously worn away by two processes—weathering and erosion.

11. The running water in the river erodes the landscape. Due to continuous erosion and deposition along the sides of the meander, the ends of the meander loop come closer and closer.

12. As the river approaches the sea, the speed of the flowing water decreases and the river begins to break up into a number of streams called distributaries. Each distributary forms its own mouth. The collection of sediments from all the mouths forms a delta.

13. The erosion and deposition of the sea waves gives rise to coastal landforms. From the striking of sea waves to the rocks, hollow like caves are formed in the rocks which are called sea caves. When these cavities become bigger and bigger only the roof of the caves remains, thus forming sea arches.

14. Glaciers are rivers of ice which erode the landscape by bulldozing soil and stones to expose the solid rocks below.

15. The material carried by the glaciers, such as rocks, sand and silt gets deposited. These deposits form gla­cial moraines.

16. An active agent of erosion and deposition in the deserts is wfind. It makes rocks in shape of a mushroom called mushroom rocks.

17. When the wind stops blowing, the sand falls and gets deposited in low hill like structures. These are called sand dunes.

18. When the grains of sand are very fine and light, the wind can carry it over long distances, when such sand is deposited in large areas, it is called loess.

Notes of Geography Class 7 Chapter 3 Important Terms

Focus: A place of movement inside the earth.

Epicentre: A place on surface above the focus.

Meander: In the plains, large bends of rivers.

Distributary: When river streams form new stream.

Erosion: Corrosion of earth due to water, wind and ice etc.

Waterfall: When the river tumbles at steep angle over very hard rocks or down a steep valley side it forms a waterfall.

On this page, you will find NCERT Class 7 Geography Chapter 2 Notes Pdf free download. CBSE Class 7 Social Science Notes Geography Chapter 2 SST Inside Our Earth will seemingly help them to revise the important concepts in less time.

Inside Our Earth Class 7 Notes Social Science Geography Chapter 2

CBSE Class 7 Geography Chapter 2 Notes Understanding The Lesson

1. The earth is a dynamic planet. It is constantly undergoing changes inside and outside.

2. The uppermost layer over the earth’s surface is called the crust. It is the thinnest layer and its depth is about 40 km its range is about 35 km on the continental masses and only 5 km. on the ocean floors.

3. The earth’s crust is made up of various types of rocks. Any natural mass of mineral matter that makes up the earth’s crust is called a rock. Rocks can be of different colour, size and texture.

4. The main mineral constituents of the continental mass are silica and alumina. It is called ‘sial’. The oceanic crust mainly consists of silica and magnesium. It is therefore called ‘sima’.

5. Below the crust is the mantle which extends up to a depth of 2900 km.

6. In the earth, the innermost layer is the core with a radius of about 3500 km. It is mainly made up of nickel and iron and is called ‘nife’. The core has very high temperature and pressure.

7. There are three major types of rocks: igneous rocks or primary rocks, sedimentary rocks and metamorphic rocks.

8. Igneous rocks further can be classified as Intrusive rocks and Extrusive rocks.

9. Rocks roll down, crack, and hit each other and are broken down into small fragments. These smaller par­ticles are called sediments. These sediments form sedimentary rocks.

10. Rocks are very useful to us. The hard rocks are used for making roads, houses and buildings.

11. Under certain conditions, one type of rock changes to another type in a cyclic manner. This process of transformation of the rock from one to another is known as the rock cycle.

Notes of Geography Class 7 Chapter 2 Important Terms

Fossils: The remains of the dead plants and animals trapped in the layers of rocks are called fossils.

Core: Innermost layer of the earth.

Rocks: Natural masses of mineral matter.

Sediments: These are small fragments of rocks.

Rock cycle: The process of transformation of rock from one to another.

Igneous: This is a Latin word which meant fire.

Metamorphic: Change of form.

On this page, you will find Reproduction in Plants Class 7 Notes Science Chapter 12 Pdf free download. CBSE NCERT Class 7 Science Notes Chapter 12 Reproduction in Plants will seemingly help them to revise the important concepts in less time.

CBSE Class 7 Science Chapter 12 Notes Reproduction in Plants

Reproduction in Plants Class 7 Notes Understanding the Lesson

1. The production of new individuals or young ones from their parents is known as

2. Most plants have roots, stems and These are called the vegetative parts of a plant. After a certain period of growth, most plants bear flowers.

3. There are two ways by which plants produce their offsprings; (i) asexual and (ii) sexual

4. There are several methods of asexual reproduction such as fragmentation, budding, spore formation and vegetative propagation.

5. When reproduction is through the vegetative parts of the plant, like stem, leaves or roots, it is known as vegetative propagation.

6. Artificial methods of vegetative propagation include layering, cutting and grafting.

7. Flowers are the reproductive parts of a plant.

8. The stamens are the male reproductive part and the pistil is the female productive part of the flower.

7. A stamen consists of the anther and the filament. Anther contains pollen grains which produce male gam­etes.

8. A pistil consists of stigma, style and ovary. The ovary contains one or more ovules. The female gamete or the egg is formed in an ovule.

9. The flowers which contain either only the pistil or the only the stamens are unisexual flowers and those that contain both stamens and pistil are called bisexual flowers. For example, corn, papaya, etc., pro­duce unisexual flowers, whereas mustard, rose, etc. have bisexual flowers.

10. The transfer of pollen from the anther to the stigma of the flower is called It takes place with the help of wind, water and insects.

11. If the pollen lands on the stigma of the same flower, it is called self-pollination [Fig. 12.3(a)],

12. When the pollen of a flower lands on the stigma of another flower of the same plant, or that of different plant of the same kind, it is called cross-pollination [Fig. 3(b)].

13. The process of fusion of male and female gametes to form a zygote is called fertilisation.

14. The cell which results after fusion of the gametes is called a The zygote develops into an embryo.

15. Fruit is the mature ovary whereas ovules develops into a seed, which contains the developing embryo.

16. Seeds are dispersed to different places. That is why same kind of plants grow at different places in nature. Seed dispersal is aided by wind, water and animals.

17. Seed dispersal helps the plants in

• preventing overcrowding,
• avoiding competition for sunlight, water and minerals and
• invading new habitats.

Class 7 Science Chapter 12 Notes Important Terms

Asexual reproduction: It is the type of reproduction in which new individuals are formed without the fusion of male and female gametes. For example, fragmentation, spore formation, cutting, layering, etc.

Budding: Budding is a form of asexual reproduction in which a new organism develops from an out­growth or bud due to cell division at one particular site.

Embryo: The zygote formed after fertilisation divides many times to form a multicellular structure called an embryo inside the seed. Embryo germinates to form a plant.

Fertilisation: The process of fusion of male and female gametes (to form a zygote) is called fertilisation.

Fragmentation: A type of asexual reproduction process, in which an organism breaks up into two or more fragments or pieces that can grow into new individuals is called fragmentation.

Gametes: The male and female reproductive cells are called gametes. In plants pollen grains produce male gametes and ovules produce female gametes.

Hypha: Any of the thread-like filamentous structure in fungus is called hypha.

Ovule: It is a structure inside the ovary which contains female gamete inside it.

Pollen grain: Pollen grain is male reproductive cells which produce male gametes.

Pollen tube: The tubular outgrowth from the pollen, grain that penetrates the ovule and releases male gametes there.

Pollination: The transfer of pollen from the anther to the stigma of a flower is called pollination.

Reproduction: It is the process by which new organisms are produced from their parents.

Seed dispersal: The spreading or transport of seed to different places is called seed dispersal.

Sexual reproduction: It is the type of reproduction in which new individuals are formed due to fusion of male and female gametes. For example, when plants reproduce with the help of seeds.

Spore: The spore is an asexual reproductive body which is covered by a hard protective coat to resist unfavourable conditions such as high temperature and low humidity.

Sporangium: It is an enclosure in which spores are formed.

Vegetative propagation: When new plants are formed from vegetative parts (roots, stems, leaves and buds) of the plants, it is known as vegetative propagation.

Zygote: In sexual reproduction, the cell form from the fusion of male and female gamete is called a zygote.

On this page, you will find Transportation in Animals and Plants Class 7 Notes Science Chapter 11 Pdf free download. CBSE NCERT Class 7 Science Notes Chapter 11 Transportation in Animals and Plants will seemingly help them to revise the important concepts in less time.

CBSE Class 7 Science Chapter 11 Notes Transportation in Animals and Plants

Transportation in Animals and Plants Class 7 Notes Understanding the Lesson

1. All organisms need food, water and oxygen for survival.

2. In human, circulatory system consists of the heart and blood vessels.

3. Blood is a fluid which transports various essential substances to the body.

4. Blood has three major cells-Red Blood Cells (RBC), White Blood Cells (WBC) and blood platelets.

5. Blood is red in colour due to the presence of a red pigment,

6. Veins are the vessels that carry carbon dioxide-rich blood from all parts of the body back to the heart.

7. Arteries carry oxygen-rich blood from heart to all parts of the body.

8. The capillaries join up to form veins which empty in the heart.

9. Heart pumps the blood throughout the body.

10. The human heart beats about 70-80 times per minute in an adult person. This is called heart rate.

11. Stethoscope is an instrument mostly used by doctors to feel the heart beats of a person.

12. Organisms such as sponges and Hydra do not have any circulatory system.

13. The process of removal of wastes produced in the cells of living organisms is called excretion.

14. Excretory system of humans consists of two kidneys, two ureters, a urinary bladder and urethra.

15. Fish excrete waste substances such as ammonia which directly dissolve in water.

16. Birds, insects and lizard excrete uric acid in semi-solid form.

17. A group of cells that perform specialised function in an organism is called a

18. Vascular tissue are pipe-like vessels which conducts water and nutrients from the soil to other parts of the plant and distributes food from the leaves to other parts of the plant.

19. Xylem is a vascular tissue which helps in the transportation of water and nutrients in the plant.

20. Phloem is a vascular tissue in the plant which transports the produced food to all parts of the plant.

21. The evaporation of water vapour from the small openings on leaves of the plant is called It cools the plant.

22. Transpiration generates a force which pull up water absorbed by root to reach leaves and stem.

Class 7 Science Chapter 11 Notes Important Terms

Ammonia: It is a colourless gas, having a strong pungent odour. It is highly soluble in water and alcohol.

Artery: Artery is the blood vessel which carries oxygen-rich blood from the heart to all parts of the body.

Blood: It is a fluid connective tissue having various types of cells such as RBCs, WBCs and platelets. It flows in the blood vessels.

Blood vessels: Blood vessels are long channels which carry blood from one part of the body to the other, g., arteries, veins, capillaries, etc.

Capillaries: Capillaries are very thin blood vessels that form a network between arteries and veins.

Circulatory system: Various organs and tissues involved in circulating blood and lymph throughout the body is called the circulatory system.

Dialysis: Dialysis is the process of removing toxic substances or metabolic wastes from the bloodstream artificially. It is generally used in the patients with kidney failure.

Excretion: The removal of waste products from the body is called excretion.

Excretory system: The system of an organism’s body that performs the function of excretion is called excretory system. It comprises of two kidneys, two ureters, a urinary bladder and a urethra.

Haemoglobin: It is the protein which gives red blood cells their characteristic colour. Its prime function is to transport oxygen from the lungs to the body tissues and carbon dioxide from body tissues to the lungs.

Heartbeat: The rhythmic contraction and expansion of the heart muscle is called heartbeat.

Kidney: It is either of two bean-shaped excretory organs that filter the blood to eliminate the nitrogenous wastes from it.

Phloem: Phloem is a vascular tissue in plant which transports the produced food from leaves to all parts of the body.

Plasma: The fluid part of the blood is called plasma.

Platelets: Platelets are very small disc-shaped cells present in the blood. They help to clot the blood from a cut or wound.

Pulse: Pulse is the rate at which the heartbeats.

Red blood cells: Red blood cells are disc-shaped, biconcave cell in the blood that contains haemoglobin, lacks a nucleus and transports oxygen and carbon dioxide to and from the tissues.

Root hair: Plant roots have hair-like structures called root hair. They could be considered as clusters of very fine delicate, thread-like structures.

Stethoscope: It is an instrument used by physicians to feel the actions of the heart.

Sweat: Salty fluid released through small pores on the skin is called sweat. Sweat is secreted by sweat glands.

Tissue: A group of cells, similar in structure, that perform a specified function is called a tissue.

Urea: A nitrogen-containing colourless and crystalline compound produced in the body of mammals as a result of breakdown of proteins is known as urea. It is excreted out from the body through urine.

Ureter: A thin muscular tube that transports urine from kidney the urinary bladder is called ureter.

Urethra: Urethra is a duct through which urine is discharged in most mammals.

Uric acid: It is a white tasteless, odourless crystalline product of protein metabolism. It is the main excre­tory product in birds reptiles and insects.

Urinary bladder: A membranous sac for temporary retention of urine is called urinary bladder.

Vein: It is a blood vessel that carries blood rich in carbon dioxide from the capillaries towards the heart.

White blood cells: It is colourless cells in the blood that have a nucleus and cytoplasm. They are impor­tant part of the body’s defence system.

Xylem: A vascular tissue present in the plants for the transportation of water and nutrients in the plants is called xylem.

On this page, you will find Respiration in Organisms Class 7 Notes Science Chapter 10 Pdf free download. CBSE NCERT Class 7 Science Notes Chapter 10 Respiration in Organisms will seemingly help them to revise the important concepts in less time.

CBSE Class 7 Science Chapter 10 Notes Respiration in Organisms

Respiration in Organisms Class 7 Notes Understanding the Lesson

1. The breakdown of food in the cells with the release of energy is known as cellular respiration.

2. The cells of all organisms go through the cellular respiration.

3. Aerobic respiration is said to occur when the breakdown of glucose takes place with the use of oxygen.

4. The breakdown of food without using oxygen is called anaerobic respiration.

5. Organisms that can survive in the absence of air are called anaerobes, e.g.,

6. Breathing means taking in air rich in oxygen and giving out air rich in carbon dioxide with the help of respiratory organ.

7. The taking in of air rich in oxygen into the body is called

8. The giving out of air rich in carbon dioxide is called

9. The number of times a person breathes in a minute is called the breathing rate.

10. During inhalation, our lungs expand and then come back to the original state as the air moves out during exhalation.

11. Increased physical activities enhances the rate of breathing.

12. Cow, buffalo, dog and cat have respiratory organs and mechanism of breathing similar to those of humans.

13. In-plant, roots take in air present in the soil. Leaves have tiny pores called stomata, for exchange of gases.

14. The small openings on the sides of the body of some insects and cockroaches are called Gills help fish to breathe in water.

15. Earthworms breathe through their skin.

Class 7 Science Chapter 10 Notes Important Terms

Aerobic respiration: When breakdown of glucose takes place with the use of oxygen, it is called aerobic respiration.

Anaerobic respiration: The breakdown of food without using oxygen is called anaerobic respiration.

Breathing rate: The number of times a person breathes in a minute is called the breathing rate.

Cellular respiration: The breakdown of food in the cells with the release of energy is called cellular respiration.

Diaphragm: A muscular partition separating the abdominal and thoracic cavities is called diaphragm.

Exhalation: The breathing out of air rich in carbon dioxide is called exhalation.

Gills: Gills are respiratory organs of aquatic animals that breathe oxygen dissolved in water.

Lungs: Lungs are sac-like respiratory organs in the chest of vertebrates. It serve to remove carbon dioxide and provide oxygen to the blood.

Inhalation: The breathing in of air rich in oxygen is called inhalation.

Spiracles: Spiracles are small openings on the body of cockroaches and insects for breathing.

Tracheae: Tracheae are the air tubules forming the respiratory organ of most of the insects.

Ribs: The twelve pairs of curved arches of bones extending from the spine toward the sternum in human are called ribs.

On this page, you will find Soil Class 7 Notes Science Chapter 9 Pdf free download. CBSE NCERT Class 7 Science Notes Chapter 9 Soil will seemingly help them to revise the important concepts in less time.

CBSE Class 7 Science Chapter 9 Notes Soil

Soil Class 7 Notes Understanding the Lesson

1. Soil is one of the most important natural resources for supporting life on the earth.

2. The rotting dead matter in the soil is called humus.

3. Soil is formed by breaking down of rocks by the action of wind, water and climate and this process is called weathering.

4. A vertical section through different layers of the soil is called the soil profile. Each layer differs in feel (texture), colour, depth and chemical composition. These layers are referred to as horizons.

5. A-horizon is the uppermost layer. It is also known as the topsoil. This layer is rich in humus and minerals. It is dark, soft and porous. This provides shelter to many living organisms and roots of small plants are embedded entirely in the topsoil.

6. B-horizon is the layer which is just below the A-horizon and is known as the sub-soil. This layer is rich in minerals and is normally hard and compact.

7. C-horizon is the layer which is just below the B-horizon. This layer has partially weathered rock with a lot of cracks and a long narrow opening.

8. Bedrock is the bottom-most layer in soil profile and is known as the bedrock. This is the type of layer which is full of hard rock.

9. The mixture of rock particles and humus is called the soil. Soil can be classified into three main types based on the proportion of soil particles they are composed of. They are

• Sandy soil
• Clayey soil and
• Loamy soil.

10. Sandy soil contains a larger proportion of big particles. It is well aerated and water drains quickly in this type of soil.

11. Silt soil contain soil particles of size in between sand and clay. Silt feels smooth and powdery.

12. Clayey soil contains a larger proportion of fine particles. It has little air spaces between the particles. Water does not drain quickly in this type of soil.

13. Loamy soil contains almost equal proportion of large and fine particles. Loamy soil is a mixture of sand, clay and silt. It also has a lot of humus in it.

14. Following are the properties of soil:

• Soil colour
• Soil texture
• Water-holding capacity
• Percolation rate

15. Soil contains water in the form of moisture.
16. Different soils have different water holding capacity. It is highest in clayey soil and least in sandy soil.
17. Percolation rate of water is different in different types of soil. It is highest in sandy soil and least in the clayey soil.
18. The factors that affect soil are wind, rainfall, temperature, light and humidity. These factors also affect the soil profile and bring changes in the soil structure.
19. The removal of topsoil by the action of water and wind is called soil erosion. Following are some factors which lead to soil erosion:

• Large scale cutting of trees-deforestation.
• Overgrazing in forests.
• Deep ploughing and forests fires also lead to soil erosion.

20. Planting more and more trees or afforestation helps in preventing soil erosion as plant roots bind the soil.
21. Preventing overgrazing, doing terrace farming and planting windbreaks can also help in controlling soil erosion.

Class 7 Science Chapter 9 Notes Important Terms

Clayey: It is a type of soil which have large proportion of fine particles. It has little air space between the particles. Water does not drain quickly in these type of soil.

Humus: A dark-brown or black organic component of soil, formed by the decomposition of leaves and other plant material by soil microorganisms.

Loamy: This type of soil contains almost equal proportions of large and fine particles. It is a mixture of sand, clay and silt.

Moisture: Soil contains water in the form of moisture. Moisture content of a soil depends upon its type and source.

Percolation: Percolation means the movement of water through the soil. It is the rate at which water flows or trickles through porous soil.

Sandy: It is a type of soil which contains a larger proportion of big particles. It is gritty with lot of air spaces between its particles. It is well aerated. Water drains quickly in this type of soil.

Water retention: It is the property of soil to hold a given amount of water which can be used by the crop.

On this page, you will find Winds, Storms and Cyclones Class 7 Notes Science Chapter 8 Pdf free download. CBSE NCERT Class 7 Science Notes Chapter 8 Winds, Storms and Cyclones will seemingly help them to revise the important concepts in less time.

CBSE Class 7 Science Chapter 8 Notes Winds, Storms and Cyclones

Winds, Storms and Cyclones Class 7 Notes Understanding the Lesson

1. The moving air is called wind.

2. Air exerts pressure on all object. This is called air pressure.

3. Increased wind speed is accompanied by a reduced air pressure.

4. Air moves from a higher pressure region to a lower one. The greater the difference in pressure, the faster the air moves.

5. On heating the air expands and occupies more space. Hence, it becomes lighter. The warm air is, there­fore, lighter than cold air. That is the reason that the smoke goes up.

6. At a place, where warm air rises, the air pressure is reduced and the cooler air moves to   that place.

7. Wind currents are generated due to uneven heating on the earth. High speed winds are accompanied by reduced pressure.

8. Regions nearer to the equator get maximum heat from the sun. The air in these regions gets warm. The warm air rises, and the cooler air from the region in the 0-30 degrees latitude belt on either side of the equator moves in.

9. At the poles, the air is colder than that at latitudes about 60 degrees. The warm air at these latitudes rises up and the cold wind from the polar regions rushes in, to take its place. In this way, wind circulation is set up from the poles to the warmer latitudes.

10. Due to uneven heating of land and water, in summer, the land near the equator warms up faster and most of the time the temperature of the land is higher than that of water in this oceans.

11. In winter, the direction of the wind is from the land to the ocean.

12. The wind from the ocean carry water and bring rain. It is a part of the water cycle.

13. The monsoon winds carry water and it rains.

14. The winds blow from the oceans towards the land in summer. These are called monsoon winds.

15. There are certain situations, in nature itself, that can sometimes create disasters like thunderstorms and cyclones. They pose threat to humans, animals and plant life.

16. The strong upward rising winds produced by the rising temperature carry water droplets upward where they freeze and fall down again. The swift movement of the falling water droplets along with the rising air create lightning and sound. It is this event that is called

17. The chain of events of thunderstorm ends with the formation of a very low-pressure system with very high-speed winds revolving around it. It is this weather condition that we call a

18. A cyclone is known by different names in different parts of the world such as ‘hurricane’ in the American continent, ‘typhoon’ in Philippines and Japan, etc.

19. Tornado is a dark funnel-shaped cloud that reaches from the sky to the ground.

20. Self-help is the best help. Therefore it is better to plan in advance and be ready with defence against any approaching cyclone.

Class 7 Science Chapter 8 Notes Important Terms

Anemometer: The instrument that measures the speed of wind is called an anemometer.

Cyclone: A violent storm with wind speed of 120 to 200 km/hr is called a cyclone. It is accompanied by strong winds and heavy rain. It is a very low-pressure system with a very high speed winds revolving around.

Hurricane: A cyclone is known as hurricane in the American continent.

Lightning: A flash of bright light produced by an electric discharge between clouds or between clouds and the ground is called lightning. It occurs when two clouds with unlike charges approach each other.

Low pressure: A condition of the atmosphere in which the pressure is below average. It is also caused when warm air rises up.

Monsoon winds: The wind from the oceans carry water and bring rain. These winds are called monsoon winds.

Pressure: Pressure is exerted by air around us.

Thunderstorms: The rising temperatures produce strong upward rising winds. These winds carry water droplets upwards, where they freeze and fall down again. The swift movement of the falling water droplets along with the rising air create lightning and sound. It is this event that is called thunderstorm.

Tornado: A tornado is a dark funnel-shaped cloud that reaches from the sky to the ground. It may form within a cyclone.

Typhoon: A cyclone is called a typhoon in Philippines and Japan.

Wind flow pattern: Winds flow from oceans towards the land in summer and from land to oceans in winter.

On this page, you will find Weather, Climate and Adaptations of Animals to Climate Class 7 Notes Science Chapter 7 Pdf free download. CBSE NCERT Class 7 Science Notes Chapter 7 Weather, Climate and Adaptations of Animals to Climte will seemingly help them to revise the important concepts in less time.

CBSE Class 7 Science Chapter 7 Notes Weather, Climate and Adaptations of Animals to Climate

Weather, Climate and Adaptations of Animals to Climate Class 7 Notes Understanding the Lesson

1. The day-to-day condition of the atmosphere at a place with respect to the temperature, humidity, rainfall, wind speed, etc., is called the weather at that place.

2. The temperature, humidity and other factors are called elements of the weather.

3. To record the maximum and minimum temperatures during day, there are special thermometers, called maximum and minimum thermometers.

4. The maximum temperature of the day occurs generally in the afternoon while the minimum occurs in the early morning.

5. All the changes in weather are driven by the sun.

6. The average weather pattern takes over a long time, say 25 years, is called the climate of the place.

7. Mean temperature for a given month is found by first finding the average of the temperatures recorded during the month then calculating the average of such average temperatures over many years.

8. The annual record of long-term average temperature and rainfall at a particular place is called climate chart.

9. The tropical and the polar regions are the two regions of the earth, which have severe climatic conditions.

10. Animals are adapted to survive in the conditions in which they live.

11. Animals in the polar region are adapted to the extremely cold climate by having some special characteris­tics such as strong sense of smell, a layer of fat under the skin, white fur, wide and large paws for walking and swimming.

12. Some birds migrate to escape the harsh, cold conditions.

13. Some adaptations of animals living in tropical rainforests include living on the trees, development of strong tails, long and large beaks, sensitive hearing, sharp eyesight, ability to camouflage, etc.

Class 7 Science Chapter 7 Notes Important Terms

Adaptation: The presence of specific features and habits which enable a plant or animal to live in a particular habitat is called adaptation.

Climate: The average weather pattern taken over a long time, say 25 years, is called the climate of the place.

Elements of weather: Temperature, humidity, rainfall, wind speed and other factors are called elements of weather.

Humidity: The amount of moisture in the air is called humidity.

Maximum temperature: The maximum temperature of the day occurs generally in the afternoon.

Migration: The means of escaping from the harsh and cold conditions, if adaptation is not possible then it is known as migration.

Minimum temperature: The minimum temperature of the day occurs generally in the early morning.

Polar region: The region which is very cold throughout the year with -37°C temperature is known as polar region.

Tropical rainforest: These are found in tropical regio-0n where hot and wet climate is found.

Tropical region: The region which generally have hot and wet climate because of its location around the equator is called tropical region.

Weather: The day-to-day condition of the atmosphere at a place with respect to their elements, like tem­perature, humidity, rainfall, wind speed, etc., is called as weather.