Here we are sharing complete solution of NCERT CLASS 7 SCIENCE CHAPTER 17, Forests: Our Lifeline Summary, Mind Maps, Question Answers and Multiple choice questions.
Respiration – It is the process of breaking down glucose in the presence of oxygen to release energy for carrying out life processes.
Why do we need energy?
We need energy for a variety of activities like to move from one place to another, run, walk, chew food, for the functioning of the organs in our body like the heart ,stomach and so on.
Nutrients – The components of food that are necessary for growth and development of our body are called nutrients. For example: Carbohydrate, protein, fats, vitamins and minerals .
Digestion – It is the process of breaking down the complex food substances into simpler substances.
Amino acid – Amino acids are organic compounds which combine to form proteins. Hence they are called as building blocks of proteins.
Respiratory system – The respiratory system is an organ system responsible for the exchange of gases in animals.
Nasal cavity – It is the chamber through which the inhaled air flows. It has mucus and hair.
Why is mucus important?
Mucus present in our nasal cavity helps to trap dust particles and germs which may otherwise enter the nasal cavity and can cause irritation. It also provides moisture to the air inhaled.
Nostrils – The two external openings of the nose are called nostrils.
Trachea – Trachea or the windpipe is the tube-like structure that allows passage of air into the lungs.
Why c- like cartilaginous rings present in the trachea?
A normal trachea has many rings made of cartilage. These rings are C-shaped and support the trachea by preventing it from collapsing.
Bronchi & Bronchioles – The trachea divides into two tubes called bronchi which enter the lungs. These bronchi further branch into smaller bronchioles.
What are secondary bronchi and tertiary bronchi?
The secondary bronchi are the first subdivision of the main bronchi. The secondary bronchi are further divided into tertiary bronchi which eventually branch into bronchioles.
Mucous – It is a fluid secreted by the inner lining of the nasal cavity. It moistens the air entering the body and traps foreign particles.
Pharynx – It is the common passage for air and food, it opens into the trachea and the food pipe.
Larynx / Voice box – It is a hollow structure located at the top of the windpipe from where sound is produced.
Oesophagus – Oesophagus, also known as food pipe, is a long tube-like structure that connects the mouth to the stomach. It is an important part of the digestive system.
PERISTALSIS – Peristalsis is a contraction and relaxation of muscles of the food pipe which helps in movement of food in towards the stomach.
Epiglottis – The entrance to the windpipe or trachea is guarded by a flap called the epiglottis, it closes the windpipe at the time of swallowing food.
Why do we cough?
Incomplete closure of epiglottis during swallowing causes the food to enter the windpipe. Our body responds and expels this food out from the windpipe by the mechanism of coughing.
Alveoli – Alveoli are the tiny air sacs present at the end of the bronchioles in the lungs. It plays an important role in gaseous exchange.
How gaseous exchange occurs?
When we breathe in air rich in oxygen it reaches the alveoli in the lungs, where the concentration/molecules of oxygen remains more as compared to the number of oxygen molecules in the blood vessels surrounding the alveoli, because of this difference in concentration diffusion of gaseous (oxygen and carbon dioxide) molecules occurs, oxygen molecules are taken up by RBCs and carbon dioxide is sent to the alveoli which is released out while we exhale.
Lungs – A pair of pink spongy elastic organs protected by the rib cage.
What is pulmonary?
Pulmonary is the term used in relation to the lungs.
Diaphragm – The diaphragm is a large dome shaped muscular sheet which forms the floor of the chest cavity, it contracts rhythmically while breathing which helps in expanding and contracting the space inside the lungs for inhaling and exhaling the air.
Breathing – The physical process of inhalation and exhalation of the air rich in oxygen is called breathing.
Gaseous exchange – Gaseous exchange takes place in the alveoli. It is the process of exchange of oxygen from the lungs to the cells and removal of carbon dioxide from the cells and given out through lungs .
Cellular respiration – Cellular respiration is the breakdown of glucose that produces energy. This takes place inside the cell. Energy is produced in the form of Adenosine triphosphate.
Tissue respiration – Tissue respiration refers to the exchange of gases between cells and tissue fluid.
What is internal & external respiration?
External Respiration is the exchange of gases with the external environment and the lungs.
Internal Respiration involves the exchange of gases between the wall of the alveoli and the blood capillaries, also called cellular respiration.
Inhalation – The process of taking in air rich in oxygen is called inhalation.
Exhalation – The process of giving out air rich in carbon dioxide is called exhalation.
Why do we take only oxygen while breathing although various gases are present in the atmosphere?
We do inhale all the gases present in the environment but they are not required in any process in our body so they are exhaled out in the same amount as inhaled only the oxygen molecules are taken up by the blood cells and carbon dioxide is released out.
Capillaries – Capillaries are very tiny blood vessels. It is made up of a single layer of cell.
Cell – The cell (from Latin cella, meaning “small room”) is the basic structural, functional, and biological unit of all known organisms.
Breathing rate – Number of times the person breathes in a minute is called the breathing rate. On an average breathing rate is 12-15 breaths per minute.
What is the breathing rate of a baby/child?
The average breathing rate of a toddler(1-3 years of age) is 20-24 breaths per minute.
Why do children have more breathing rate than adults?
Children have a high breathing rate because their breaths are quicker as they have little space in their lungs to perform exchange of oxygen and carbon dioxide.
Chest cavity – Chest cavity is the chamber of the body which encloses the heart and the lungs. It is enclosed by the ribs, the vertebral column, and the sternum, or breastbone. It is separated from the abdominal cavity by a muscular sheet, the diaphragm.
Diffusion – The process of movement of molecules from the region of their higher concentration to the region of their lower concentration is called diffusion.
Mitochondria – Mitochondria is a cell organelle which helps in the production of energy. It is also called the powerhouse of the cell. The energy is produced in the form of ATP molecules.
ATP – Adenosine triphosphate is the energy molecule. The energy released during the process of respiration is stored in the chemical form as ATP.
Aerobic respiration: The process of breaking down glucose in the presence of oxygen is called aerobic respiration.
Glucose+oxygen ->Carbon Dioxide + water + Energy
Anaerobic respiration: The process of breaking down glucose in the absence of oxygen is called anaerobic respiration.
Glucose-> Alcohol + carbon dioxide+energy
Glucose-> lactic acid+energy (in our muscles)
Fermentation – Fermentation is the process of converting carbohydrates (glucose) to alcohol or organic acids using microorganisms (yeast).
Lactic acid – Lactic acid is an organic acid. It is also known as milk acid.
Alcohol – Alcohol, also called by the chemical name ethanol, is a chemical that is the active ingredient in drinks such as beer, wine, and distilled spirits.
What is the Difference between breathing and respiration?
Breathing involves the process of inhaling oxygen rich air and exhaling carbon dioxide rich air. It is a physical process and does not involve production of energy, whereas Respiration is the process of breaking down glucose to produce energy which is then used by cells to carry out the cellular function. It takes place inside the cells.
- The chemical processes that occur in the body of living organisms is called a biochemical process.
- Eg: The food that we eat is converted into energy is a biochemical process.
Muscle cramp – A muscle cramp is a strong contraction of the muscles which causes it to tighten. This stiffness of muscle is very painful. A hot water bath or a massage can help in getting relief from the muscle cramps.
Why does hot water bath or massage give us relief from muscle cramps?
- Muscle cramps occur when there is anaerobic respiration taking place in our muscles. During anaerobic respiration, glucose gets converted into lactic acid during the absence of oxygen.
- A hot water bath or a massage can help in getting relief from the muscle cramps. These two things improve blood circulation, thereby increasing the supply of oxygen to the muscles. When there is a sufficient amount of oxygen supply, lactic acid breaks down into carbon dioxide and water.
- Example for anaerobic respiration
- Process of fermentation in yeast
- In human muscle cells
- A spiracle is the opening in the exoskeletons of insects which allows air to enter the trachea.
- Air enters the insect’s body through the spiracles. For example, in cockroaches, mosquito spiracles are present.
Tracheole – Tracheole is a fine respiratory tube of the trachea of an insect or a spider, part of the respiratory system. Tracheoles are about 1 µm in diameter, and they transport oxygen to cells.
Slimy – Covered with slime, which is wet and slippery
Earthworm – Earthworms are segmented worms. They are the common inhabitants of moist soil and feed on organic matter.
Amphibian – Amphibians are a class of animals which can survive both on the land and in the water. Eg: Frogs, Toads etc.
Gills – A gill is a respiratory organ found in many aquatic organisms which helps take up dissolved oxygen from water and release carbon dioxide.
Tadpoles – A tadpole is the young stage of an amphibian, it lives in water, has a tail and breathes through gills.
Dissolved meaning – To “dissolve” is defined as to become broken up or absorbed by something or to disappear into something else. When sugar becomes absorbed into water, this is an example of when sugar dissolves into water
Blood vessels – Blood vessels are a network of pathways through which blood travels throughout the body. Arteries and veins are the two primary types of blood vessels in the circulatory system of the body.
Blowholes – Usually dolphins and whales have a hold on the top of their head which is used by them for breathing. These holes are called the blow holes.
Stomata – Stomata are the minute openings, generally found in the lower side of leaves. They are typically found in plant leaves and can also be found in stems and other parts of plants.
Guard cells – The stomata consist of minute pores called stoma surrounded by a pair of guard cells. The guard cells are specialized, bean-shaped cells, which are found surrounding the stoma and are connected at both ends.
Root hair – A hair like outgrowth of a plant root that absorbs water and minerals from the soil is called root hair.
Seed – A seed is an important part of a flowering plant. They give rise to a new plant. They may be of different shapes, colors and sizes. E.g. – Bean seed.
Germination – The process by which new plants grow from a seed is called germination. It is a process that takes place when the embryo within the seed becomes active and starts to grow into a young baby plant.
Root – It is the part of a plant that grows under the ground. It absorbs water and minerals from the soil. They also anchor the plant firmly in the soil and also bind the soil together.
Shoot – It is the aerial part of a plant (develops above the ground). It includes stems, leaves, buds, flowers & fruits.
Topsoil – Topsoil is the uppermost layer of the soil which is rich in organic matter & supports the growth of plants.
Tap root – Taproots have a main central root from which small, lateral roots come out. E.g.- Mustard, carrot, beetroot, parsley, china rose etc.
Fibrous root – Fibrous roots do not have a main root & all roots seem similar and arise from the same point. E.g.- Rice, wheat, maize, marigold, banana etc.
Burdock – It is a plant found all over the world. Its roots are used as food. Seeds and leaves of this plant are also used for medicinal purposes.
- They are the components present in food which are important for life & provide us energy, they are considered as building blocks for growth and repair.
- Major nutrients required for plants are Nitrogen, Phosphorus and potassium.
Lateral root – Lateral roots are the smaller roots that come out from the main root and help anchor the plant into the soil.
Stem – It is the part of a plant present just above the ground. It helps in conduction of water and minerals absorbed by roots from the soil. It bears leaves, flowers and fruits.
Herb – Herbs are short plants, with green and delicate stems. Compared to other plants, these plants have very few branches and come off easily from the soil. E.g- Grass, Mint, and Wheat etc.
Shrub – Shrubs are medium-sized, woody plants taller than herbs and shorter than a tree. They have bushy, hard, and woody stems with many branches. Eg: Rose, Jasmine, Lemon and Tulsi.
Tree – Trees are big and tall plants. They have very thick, woody and hard stems called the trunk. The trunk gives rise to many branches that bear leaves, flowers and fruits. Eg : Mango, Banyan and Coconut.
Tender stem – The thin and delicate stems are called tender stems. For example Broccoli- we can eat the stalk and flower both.
Trunk – The thick and main stem of the tree from which branches grow is called trunk.
Creepers-Creepers are the plants that creep on the ground. They have very weak, long, thin stems that can not stand upright. Eg: Watermelon, Strawberry, Pumpkin and Sweet potatoes.
Climbers – Climbers have a very thin, long and weak stem which cannot stand upright but they can use support to grow. Eg: Pea plant, Grapevine, Sweet gourd, Money plant.
Grapevine – The stem of grape plants, which grows upward with the help of tendril.
Tendril – A tendril is a modified stem or leaf with a thread-like shape that is used by climbing plants for support.
Photosynthesis – Photosynthesis is a process of synthesis of food in plants using carbon dioxide and water in the presence of sunlight with the help of chlorophyll pigment.
Leaf – Leaf is a green flat part of a plant, it contains chlorophyll which helps in preparation of food by the process of photosynthesis.
Midrib –The thick prominent vein that runs along the middle of the lamina is called midrib. Midrib divides the surface of the lamina into two.
Vein – The lines on the leaf that comes out from a midrib are called veins.
Petiole – Petiole is the long, thin, stalk that connects the leaf blade to the stem.
Lamina – It is also known as leaf blade. It is generally the green, flat surface of the leaves.
Venation – The pattern or the arrangement of veins on the leaf is called venation. It can be either reticulate venation or parallel venation.
Reticulate Venation – The veins are arranged in a net-like fashion on both sides of midrib. E.g.: Rose plant, Hibiscus etc.
Parallel venation – In a parallel venation, the vein runs parallel to each other. E.g.: Maize, Banana etc.
Relation between different types of leaves and roots –
Leaf venation and the type of roots in a plant are related. Plants with fibrous roots have parallel venation in their leaves. Plants with tap roots have reticulate venation in their leaves.
Transpiration- Transpiration is the loss of water in the form of water vapour from aerial parts ( i.e parts which are exposed to the air ) of the plant.
Flower – Flowers are the most colorful part of a plant. It is also called the reproductive part as it carries the reproductive organs. Eg: Rose and Hibiscus.
Petal – Petal is the colorful part of a flower. It has fragrance and helps in attracting the insects for pollination.
Sepal – It is the green leaf-like part of the flower present below the petals. It protects the inner parts of the flower when it is a bud.
Stamen – The male reproductive part of the flower is called stamen. It consists of anther and filament.
Pistil – The female reproductive part of the flower is called Pistil. It consists of three parts- stigma, style and ovary.
Anther – The oval/round structures present on the top of the filament is anther. They produce pollen grains.
Filament – A long thread-like structure on the top of which anther is present.
Stigma – It is the topmost part of the pistil (female reproductive part of a flower) which receives the pollen grain.
Style – It is the long tube-like structure which connects stigma to the ovary.
Ovules – Ovules are present inside the ovary and develop into seed.
Incomplete flower– A complete flower is the one that consists of sepals, petals, stamens and pistils. If the flower lacks any one of these parts, then it is an incomplete flower. Example -Sweet corn.
Complete flower– A complete flower is the one that consists of sepals, petals, stamens and pistils. Example – Rose, Hibiscus.
Pollination- The transfer of pollen grains from anther to stigma is known as pollination.
Fertilization- The fusion of male gamete and female gamete to form a zygote is known as fertilization.
Edible- Anything that can be eaten is known as edible.
Seed dispersal- The spreading of seeds to different places is known as seed dispersal.
Embryo- It is a stage in development of the zygote.
Conduction– It is the transfer of water and minerals from one part of the plant to another part.
Sessile leaves- Sessile leaves are directly attached to the stem without a petiole. Example- Saffron.
Mosses- Mosses are small non-flowering plants. They are predominantly found in aquatic environments.
Algae- Algae are organisms that are capable of performing photosynthesis and are mostly aquatic organisms.
Monocots- Monocots are the flowering plants in which the seeds have only one cotyledon. Example: Rice, Grass, Maize etc.
Dicots- Dicots are the flowering plants in which the seeds have two cotyledons. Example: Rose, Pea, Mango etc.
Experiment to test for the presence of starch in leaves –
Take a leaf in a test tube and pour alcohol solution till it completely covers the leaf. Now put the test tube in a beaker having water. Heat the beaker till all the green colour from the leaf comes out into the alcoholic solution in the test tube then take out the leaf and wash it with water and pour some iodine solution over it. The iodine solution is brown in colour but when it comes in contact with starch it turns blue-black, this confirms the presence of starch in the leaf.
Why should we boil the leaf in an alcohol solution – Leaf has to be boiled in alcohol so that chlorophyll pigment in the leaf is removed and the green colour of the leaf comes out. So that it should not interfere in our result.
Why are leaves green in colour – Leaves are green in colour due to presence of chlorophyll pigment.
Why are petals colourful – Petals are colourful so that they can attract insects for the process of pollination.
Example of Plants with joined sepals– Example of Plants with joined sepals are Hibiscus and Cotton.
Example of Plants with separate sepals – Example of Plants with separate sepals are Rose, Lily and Lotus.
Nutrition- Nutrition is the mode of taking in food by an organism and its utilisation by the body to obtain energy to do various life processes.
Nutrients- Nutrients are the substances which provide energy, and biomolecules necessary for carrying out the various body functions. These nutrients also act as building blocks for growth and repair of the body.
Macronutrients – Carbohydrates, Proteins, Fats
- Carbohydrates- Whole grains, vegetables, fruits and beans.
- Proteins- Beans, lentils, pulses, eggs, meat.
- Fats- Olive, canola, peanut, and sesame oils, Avocados.
Micronutrients – Vitamins and Minerals
- Vitamins and minerals- Different fruits and vegetables.
- Dietary fibre- Oats, fruits, vegetables, oat bran, barley.
Balanced diet – A balanced diet is a diet which contains all the vital nutrients like carbohydrate, protein, fat, vitamins and minerals in the right amount. A healthy and balanced diet helps to reduce the risk of diseases and improves overall health.
Vitamin – Vitamin is a micronutrient that is not prepared by the body in sufficient amounts. This is the reason why it is necessary to take in from outside sources for the normal functioning of the body.
- Deficiency diseases are diseases that are caused by the lack of certain essential nutrients in one’s diet over a prolonged period of time.
- A balanced diet is extremely important for the good health of a person. Any imbalance in the diet might lead to excess or insufficient intake of certain nutrients. Insufficient intake of a particular nutrient can lead to a deficiency disease.
Vitamin Deficiency diseases
Vitamin A (Retinol) – Deficiency of Vitamin A causes Night blindness. Vitamin A rich food sources are carrots, spinach, milk, egg, liver and fish.
Vitamin B Complex-
This include 8 types of vitamins B-
B-5 (pantothenic acid)
B-9 (folic acid)
Deficiency of Vitamin B-1 causes Beri beri disease.
Deficiency of Vitamin B-2 causes retarded growth and skin problems.
Deficiency of Vitamin B-12 causes Pernicious Anaemia. Other diseases related to Vitamin B-12 deficiency are muscle and nerve paralysis, extreme fatigue, dementia and depression.
Vitamin C (Ascorbic acid)- Deficiency of vitamin C can cause scurvy, a disease that is characterised by bleeding gums, skin spots and swelling in joints. It also affects the immune system and can even be fatal in acute conditions.
Vitamin D (Calciferol) – Vitamin D deficiency causes rickets, which leads to weakening of bones, especially near the joints. It can also lead to tooth decay.
Vitamin K (Phylloquinone) – Vitamin K is an important blood coagulating nutrient. Its deficiency is common in infants and leads to excessive bleeding due to the inability to form blood clots.
Mineral Deficiency Diseases:
Minerals are inorganic nutrients that include copper, zinc, iodine, iron, along with the calcium, potassium, magnesium and sodium.
Following is the list of a few minerals along with the deficiency diseases-
- Deficiency of Calcium causes Brittle bones.
- Deficiency of Phosphorus causes weak teeth and weakness of bones.
- Deficiency of Iron causes anaemia which is a condition in which the blood is unable to carry the required oxygen to the tissues, that also results in death.
- Deficiency of Iodine causes Goitre, which leads to enlarged thyroid gland.
- Deficiency of Copper leads to Low appetite and retarded growth.
Disease – A disease is a condition that negatively affects the normal functioning of the cells, tissues, and organs of the body.
Malnutrition – Malnutrition is a condition that results from eating a diet of low nutrient amount in it, which eventually results in health problems and deficiency diseases. Malnutrition is also known as malnourishment.
1- Kwashiorkor is acute malnutrition that occurs mostly in children between the age of 6 months and 3 years of age. This condition results from severe protein deficiencies. It is also known as “edematous malnutrition” because it is associated with oedema. The children suffering from Kwashiorkor have abnormally thin and weak bodies. They have swelling in the ankles, feet and belly which is filled with water.
2- Marasmus is the type of nutrition deficiency that is mainly caused due to the deficiency of nutrients such as carbohydrates and sometimes protein. Marasmus mainly occurs due to poverty and food scarcity. It occurs mostly in children between the age of 6 months and 1 year of age. The symptoms of marasmus are more common to the symptoms of kwashiorkor, which includes: Dizziness, Weight loss, Dehydration, lack of energy, stunted growth, Chronic Diarrhoea, shrinkage of stomach.
Ingestion – Ingestion is the process of taking in food inside the mouth. The mode of food intake varies in different organisms.
Digestion – Digestion is the process of breaking down ingested complex food molecules into simpler form. The digestion process involves the alimentary canal along with various accessory glands.
Absorption – Absorption is the process which begins in the small intestine where most of the nutrients and minerals are taken up by the bloodstream from the intestinal walls.
Assimilation – Assimilation is the process of using up the nutrients by the body for growth and development.
Egestion – Egestion is the removal of undigested food wastes out of the body through the anus in the form of the faeces.
Blood vessels – Blood vessels are the tube through which the blood circulates in the body.
The primary function of blood vessels is to transport oxygen, nutrients & waste to/from all parts of the body.
Alimentary canal – The alimentary canal is a long tube through which the food we eat is passed in the digestive tract. It begins at the mouth (buccal or oral cavity), passes through the pharynx, oesophagus or food pipe, stomach, small intestines, large intestines, rectum and finally ends at the anus. The food particles gradually get digested as they travel through various parts of the alimentary canal.
The alimentary canal is about 30 feet long from the oesophagus to the anus.
Accessory organs – Accessory organs are the organs that help in the process of digestion by pouring their secretions in the form of digestive juices. These include – liver, pancreas and salivary glands.
Oesophagus – Oesophagus is also known as a food pipe. It is a long muscular tube that connects the mouth and the stomach. It passes down the food from the mouth to the stomach.
Peristalsis – Peristalsis is the wave-like movement due to contraction and relaxations of the muscles of the alimentary canal. It pushes the food from one organ to the other. This movement is involuntary and is necessary for the movement of food down the stomach and bowels down the anus.
Types of teeth
There are 4 different types of teeth in humans. They are- Incisors, Canines, Premolars and Molars.
Milk teeth – The first set of teeth a child grows- consists of canines, incisors and premolars. These are the temporary teeth/baby teeth or deciduous teeth. These are the primary set of teeth in humans which start to erupt through the gums after the age of 6 months and generally fall off around the age of 12.
Permanent teeth – The second and final set of teeth in a human are called permanent teeth. These consist of canines, incisors, premolars and molars.
Tooth decay – Tooth decay means the damage of enamel. It generally happens when bacteria in your mouth makes acids that attack the enamel. There can be a combination of factors which leads to tooth decay which includes frequent snacking, sipping sugary drinks and not cleaning your teeth well. Tooth decay can lead to cavities or dental caries, which are holes in your teeth. If tooth decay is not treated, it can cause pain, infection, and even tooth loss.
Plaque – Plaque is a mass of germs or bad bacteria that grows on the surface of the teeth. This can be seen as a soft, sticky film that builds up on your teeth. The bacteria of plaque causes tooth decay.
Salivary gland – Salivary glands are present in the mouth that secrete saliva. There are 3 pairs of salivary glands in the mouth, three(3) on each side.
Tongue – The tongue is a muscular organ. It helps with chewing, swallowing and speaking. During swallowing, the tongue pushes a tiny bit of ball- shaped mass of chewed food called a bolus, towards the back of your throat and into the opening of your oesophagus.
The presence of papillae on the tongue gives it a rough texture. It is covered with several taste buds.
Papillae – Papillae are tiny outgrowths or bumps present on the surface of the tongue that consist of the several taste buds. The presence of papillae on the tongue gives it a rough texture. They are responsible for giving the tongue its texture and are responsible for the sensation of touch.
Taste buds – Taste buds are ovoid clusters present on the surface of the tongue. These contain taste receptors which help to identify or sense the taste of the food.
Function of teeth – Teeth are used for Cutting, biting, chewing and grinding the food.
Saliva – Saliva is secreted by salivary glands. The functions of saliva are –
- It acts as digestive juice and softens the food, which further leads to the easy process of digestion.
- It moistens the food for easy swallowing.
- It helps to clean the mouth, tending to destroy germs to prevent tooth decay.
- It contains a digestive enzyme called salivary amylase, which breaks down starch into sugar.
HCl – HCl stands for Hydrochloric acid. It is the major component of gastric juice. It helps to kill germs in the food. It also activates enzymes for breakdown of certain proteins. HCl converts pepsinogen which is not active into pepsin to break proteins in our stomach.
Mucus – Mucus is a sticky substance produced by the stomach wall. This mucus protects the stomach lining from being attacked by different acids such as HCl that are used during digestion.
Gastric juices – Gastric juice is the digestive juice which is colorless, watery, acidic fluid and is secreted by the gastric glands found on the wall of the stomach. It consists of hydrochloric acid, mucus, and different enzymes.
Bolus – Bolus is round, ball-shaped and a mixture of chewed food formed by the combination of food and saliva in the mouth. The bolus is swallowed by the mouth which travels down the oesophagus to the stomach for digestion.
Chyme – Chyme is a thick semisolid mass of partially digested food that is formed in the stomach during digestion.
Starch – Starch is an organic compound. It is a polysaccharide made of many glucose molecules. It is a stored form of carbohydrate in plants.
Bile juice – Bile juice is secreted by the liver. Bile juice is a yellowish brown fluid. It is stored in the gallbladder. The main function of bile juice is to break down the fat molecules known as emulsification of fats.
Emulsification – Emulsification is the breakdown of bigger fat globules into smaller fat droplets. The fat molecules are digested and broken down into fatty acids and glycerol.
Gallbladder – Gall bladder is a pouch-like organ attached to the liver. It stores the bile juice produced in the liver.
Can we live without gallbladder?
Yes, we can. If gallbladder is not there the bile juice produced will be directly sent to the small intestine without being stored and concentrated.
Insulin – Insulin is a hormone that lowers the level of glucose (a type of sugar) in the blood. Insulin is secreted by the pancreas.
Diabetes mellitus – Diabetes mellitus commonly known as diabetes is a condition that occurs when there is excess of glucose or sugar level in the bloodstream.
Villi / Villus
- Villi are small, finger-like projections present on the inner wall of the small intestine.
- Villi increases the surface area of the intestinal walls for maximum absorption of digested food.
Rectum – Rectum is the last part of the large intestine where the undigested waste material or faeces is stored temporarily until it is eliminated out of the body through anus.
Vermiform Appendix – Vermiform appendix is a finger-like, blind-ended tube connected to the cecum of the large intestine. It serves as a microbial reservoir because it stores beneficial microbes.
Flatulence – Flatulence is a biological term for releasing gas from the digestive system through the anus.
Cellulose – Cellulose is the most abundant organic compound. Cellulose is a complex carbohydrate consisting of oxygen, carbon, and hydrogen. Cellulose is a polysaccharide made up of many glucose units. A plant’s cell wall is primarily made up of cellulose.
Anus – Anus is the last part of the alimentary canal in humans. It is a part through which the undigested waste material or faeces are eliminated out of the body.
Herbivores – Herbivores are the organisms which only eat plants. For example- cow, buffalo, deer, etc.
Why can’t humans eat grass?
It is because the grass is rich in cellulose, which is a type of carbohydrate that humans are not able to digest due to the absence of cellulose-digesting enzymes. Animals such as cows have a specialized stomach with four chambers to aid in the digestion of grass.
Rumination – The process where cud returns to the mouth in small lumps for ruminants to chew is called rumination.
Ruminants – Grass eating animals are known as ruminants. Animals like cows, goats and buffaloes eat grass.
Four parts of stomach in ruminants- Rumen, Reticulum, Omasum and Abomasum.
Rumen – Rumen is the first stomach of a ruminant
Reticulum – Reticulum is the second part of the stomach in ruminants, it passes the smaller digested particles from the rumen to the omasum.
Omasum – The omasum is where food particles that are small enough get transferred into the abomasum for enzymatic digestion.
Abomasum – The last part of the stomach (abomasum), called the true stomach as the protein digestion occurs in acidic conditions.
Cellulase – Cellulose is an enzyme that digests cellulose.
Cud – Cud is the partially digested food that is brought up again to the mouth from the first stomach of the ruminants for further chewing.
Amoeba – Amoeba is a type of unicellular organism which has the ability to alter its shape by extending pseudopods.
Unicellular – Unicellular organisms are those which are made of a single cell. Example- Amoeba, Bacteria
Pseudopodia – Pseudopodia are temporary cytoplasmic extensions, which helps the cell to move
Vacuole – Vacuole is one of the cell organelle which is prominent in plants and helps in storage of water and food materials.
Nucleus – Nucleus is one of the most important cell organelles found in eukaryotic cells. It is a membrane-bound spherical organelle present at the center of the cell, that contains the entire genetic information of the cell.
Cell membrane – The cell membrane is also known as the plasma membrane. It is a semi-permeable membrane composed of lipids and proteins. The main functions of the cell membrane includes- protecting the cell and providing support in maintaining the shape of the cell.
Food vacuole – Food vacuole is a membrane-bound vacuole formed in amoeba and helps in the digestion of food.
Digestion in amoeba – Amoeba has a flexible membrane and finger-like projections called pseudopodia. Pseudopodia forms a vacuole around it and helps in engulfing the food. When the food particle is completely trapped inside its vacuole amoeba secretes its digestive enzymes and digests the food. The digestive enzymes are secreted into the food vacuole in amoeba to break down the food. The enzymes act on food particles in the vacuole and break down into simpler molecules by chemical reaction which are soluble in its body.
Siphoning – Siphoning is a mode of nutrition in which animals suck the food from substratum.
Sucking – Sucking is a mode of nutrition in which insects pierce the food item and then sucks the internal fluid of the food.
Defecation – Defecation is the process of discharge of faces from the body.
Photosynthesis – [Photo: light, Synthesis: to make] Photosynthesis is the process where, in the presence of chlorophyll, plants use the energy from the sunlight to synthesize food from raw materials like water, carbon dioxide.
Photosynthesis and Digestion
- Photosynthesis is the process by which plants make their own food in the presence of sunlight and chlorophyll pigment by using raw materials like water and carbon dioxide.
- Digestion is the breakdown of complex food molecules to obtain energy to do various life processes. Both these processes are the reverse of each other .
Plant nutrients and animal nutrients
- Plants require two types of nutrients- Macronutrients and Micronutrients.
- Macronutrients are those which are required in higher quantities which include nitrogen, phosphorus, potassium, calcium, magnesium and sulphur.
- Micronutrients are those which are required in minute quantities which include boron, chlorine, copper, iron, manganese, molybdenum, and zinc.
Animal nutrients are mainly what the plants produce. These are again of two types- Macronutrients and micronutrients.
- Macronutrients – Carbohydrates, Proteins, Fats
- Micronutrients – Vitamins and Minerals.
- Food gives us energy and this energy is measured in calories. A calorie is the unit of energy.
- A calorie is the amount of energy needed to raise the temperature of one gram of water by one degree centigrade.
- Standard unit of food energy is kilocalorie 1 kilocalorie =1000 calories
Glycogen – Glycogen is a polysaccharide of glucose that serves as a form of energy storage in animals.
Fats – Fat is a stored form of energy. It produces energy in the body when required. The fat lying underneath the skin renders protection to the body against a rapid heat loss.
Proteins – Proteins are made up of amino acids that join together to form long chains. There are 20 amino acids that help form thousands of different proteins in your body.
- Component of every cell.
- Components of hair, nails. E.g. Keratin protein.
- Build and repair damaged tissues.
- Make Necessary enzymes and hormones.
- Important building blocks of bones, cartilage, muscles, skin and blood.
Proteins can’t be stored in our body like carbohydrates and fats, no reservoir, should be replenished on a daily basis.
Protein – Proteins are a type of macronutrients required by the body for growth and repair. Hence, they are also known as “body building food”. Milk, fish, meat, cheese and eggs are the main sources of animal proteins. Plant based proteins can be obtained from pulses and beans.
Putrefaction – Slow decay of certain parts of the body.
- Helps to regulate body temperature
- Transports nutrients and oxygen to the all parts of the body
- Helps in the digestion and excretion of waste products
- Prevents dry skin, reduces the intensity of fever and headache
Dog’s digestive system – The dog digestive system includes all the organs involved in eating and processing food. The digestion takes 6 hours to complete.
Cow’s digestive system – The digestion on cows takes about 80 hours as they have to process their food since their food is grass and it contains cellulose which is hard to process. The friendly bacteria in the cow’s intestine or gut help in the digestion process called rumination.
Chicken’s digestive system – Chicken’s don’t have teeth, to make up, they swallow small stones which are stored in another organ called gizzards, these small stones help to grind the cereals which they eat.
Rabbit’s digestive system
- The food which are eaten by the rabbits can’t be digested by the rabbit’s digestive system, the materials from the intestine is packaged in to small round moist pellets, microorganisms present in their intestine acts on these moist pellets to convert the undigested food in to the digestible nutrients .
- The nutrient rich pellets which are ready in the intestine must be taken into the digestive tract of the rabbit once more by the action of the brain in which they emerge this out and eaten up immediately after that ,that is they are eating their nutrient rich pellets or it’s faeces.
Shark’s digestive system – Sharks when swallowing something which they can’t digest are able to turn their stomach inside out to expel whatever they swallowed .
- Stomach secretes digestive enzymes and acids for digestion of food
- Mucus protect the stomach lining by from being burnt from acids
- Unwanted bacterias will be killed by the acidic medium
- Food is ground and mixed by the contraction of stomach’s muscular wall
- It takes 40 min to few hours for the stomach to break down the food
- Average human stomach can comfortable hold about a litre of food
- Our stomach can hold 15 ml when it is empty to 4 litres when it is full
Liver Cirrhosis – Liver flushes out the toxic substances from our blood, if we consume alcohol, the liver needs to clean up the alcohol from our body, excess consumption of alcohol causes our liver to die and this is called cirrhosis.
Vermiform Appendix – Earlier Vermiform appendix was considered as a vestigial organ, but according to recent study the appendix acts as a safe house or reservoir for good bacteria that is needed to digest our food.
Flatulence – Humans pass through 500 – 1500 ML of gases everyday ,and this can be passed through 10-15 times in a day. This passing of gas is known as flatulence. These gases are coming from the air we breathe in, which gets into our digestive tract and produced by the bacterias in the intestine.
Rumination – Ruminants or herbivores like cows, buffalo etc. have a 4 chambered stomach which contains rumen, reticulum, omasum and abomasum, it is an adaptation to prevent from being hunted down by predators while they are eating. In the four chamber rumen is the largest and most important chamber and some microorganisms and bacterias are present in the rumen, these microorganisms will produce enzymes required to digest the cellulose from plants. During digestion, food will form a soft chunk called cud, the cud produced is regurgitated back into the animal’s mouth where they can chew again. The saliva of the cow greatly aids in digesting the cud, after chewing the food bipasses into the two chambers of the stomach and directly enters into the third chamber, the walls of the third chamber mash and compact the food up much further and pass it on to the fourth chamber. The final digestion of the stomach is done there and passed on to the intestine.
Living Things – Living things are the organisms which possess life, usually identified with few characteristics such as growth, movement, reproduction etc. Examples: dogs, cats, housefly, humans, trees, shrubs etc.
Non-living things – Non-living things do not possess life, they do not have any of the characteristics of a living organism. Examples: Chairs, tables, pens, clouds, soil etc.
What are the characteristics which differentiate living organisms from nonliving things?
Living organisms possess certain characteristics like growth, movement-internally and externally, reproduction, excretion, respiration, sensitivity or response to stimuli and have a definite life span. All the characteristics are shown by the living organisms throughout their life period.
Growth – Growth is the gradual development of age, size, height, weight etc. in living things. Example: A kitten grows into a cat, A child grows into an adult human being.
Germination – Germination is the process of growth of a young plant or seedling from the seed when the suitable conditions like temperature, water and air are available.
Locomotion – Locomotion is the ability to move from one place to another.
Excretion – Excretion is a process of eliminating waste products that are being produced inside the body. Example: Kidneys help in excreting the wastes in the from of urine
Egestion – Egestion is the process of removal of undigested food from the body.
Reproduction – Reproduction is the process of producing offspring/the young ones that are similar to the parent organism.
Respiration – Respiration is the process of producing energy from the food we consume with the help of oxygen.
Breathing – Breathing is the process of taking in air (inhalation) and giving out air (exhalation). It is a part of respiration.
Stimuli and stimulus – Stimuli are the changes or events in the surroundings that make an organism respond or react to them. Example: When we touch a hot pan we get the sensation of heat, and withdraw the hand. Here, heat is the stimulus and withdrawing the hand is the response. Stimulus is a singular term and stimuli is plural.
Nutrition – Nutrition is a method/ mode by which food is consumed by the organism and its utilization for nourishing the body (to provide energy, growth, development etc.)
Photosynthesis – Photosynthesis is a process by which plants produce their own food. Plants use carbon dioxide and water to prepare their food in the presence of sunlight.
Plants – A plant is a living organism that is capable of growing in land as well as water. It produces its own food by photosynthesis. It generally has roots, stem, leaves and flowers (some plants are non-flowering) Examples: Mango tree, Sunflower, Water lily, Money plant etc.
Animals – Animals are the living organisms that show locomotion and they depend on other organisms for their food. Examples: Cats, Birds, Fishes, Humans etc.
Energy – Energy is the strength required to do any mental or physical activity. Organisms use the energy they get from food to grow, to reproduce, to respond to stimuli, to carry out daily activities etc.
Organism – An organism refers to an individual living thing that shows the characteristic features of life such as movement, reproduction, growth and development etc.
Clouds also grow in size and move from one place to another. Then why are clouds nonliving?
In living organisms all the characteristics are shown at some or the other point of life though not all at once. But clouds only show two characteristics: growth (due to accumulation of water droplets) and movement from one place to another (with the help of wind) which is different from living organisms. They do not show the remaining characteristics like respiration, excretion and reproduction. Hence, clouds are non living things.
- Stomata are the small openings (pores) that are present on the surface of the leaves.
- They are present more in number on the lower surface (under side) of the leaves. These small pores help in gaseous exchange and also help in transpiration. When stomata are open, air enters or leaves just like in the windows.
Transpiration – Transpiration is the loss of excess amounts of water in the form of water vapor from the surface of leaves with the help of tiny pores known as stomata. It helps the plant to absorb more water and minerals from the soil and also helps in keeping the plant cool during hot weather like how we sweat.
Earthworm – Earthworm is a type of worm that is found in the soil. It has bristles for movement. It is also known as the ‘Farmer’s friend’.
Lungs – Lungs are a pair of organs situated within the rib cage that are spongy and pink in color. They help in breathing.
Gills – Gills are a pair of organs found in aquatic animals such as fish, they are involved in the process of breathing under water.
Slimy – Slimy substances are the things that are wet and a little sticky.
Slimy skin – Some organisms naturally have a slimy substance on their skin which makes their skin wet and sticky. Example: Earthworms
Wastes in human body – Waste products that are being removed in human bodies are urea, salt, uric acid and other chemical substances which could be harmful.
Shedding of leaves – In unfavorable weather conditions some plants drop their leaves to reserve the food and protect themselves. This process of removing leaves is called, shedding of leaves. Plants also store waste materials in the old leaves, so that the wastes get removed when the leaves shed off.
Resin – Resin is a sticky substance which gets released or oozes out from some trees. It is insoluble in water and is used in making glues and varnishes.
Latex – Latex is a milky secretion oozes out from some plants when the plant is cut. Latex of the rubber trees is the natural source of rubber.
Secretion – A process by which a cell or an organ of a living organism produces chemical substances that are required for various functions. For example- Mouth secretes saliva
Vegetative part of a plant – Except flowers, all other parts of the plant are known as vegetative parts. Flowers are known as reproductive parts as they help in reproduction in plants. Example: Root, Stem and leaf.
Sensitivity – Sensitivity is the ability of responding to the stimuli such as heat, pain, pressure etc. It can also be termed as the response to stimuli.
Mimosa pudica/Touch me not – Leaves of the touch-me-not plant (Mimosa pudica) curl up or get folded when touched due to sudden loss of water. Hence it got the name as touch-me-not. Touch is the stimulus and curling of the leaves is the response. The plant curls its leaves as a method of self-protection so that the animals do not eat them.
Internal Movement – Movement of substance inside the body of an organism is called internal movement. Example: Movement of blood inside our body.
External Movement – Movements that take place outside the body of an organism. Example: Waving hands, Walking etc.
Life span – A period of life of an organism from its birth to death is called life span. Examples: Lifespan of dogs – 10 to 13 years, Lifespan of horse – 25 to 30 years.
Polar bear – Polar bear is an animal that lives in polar regions. It has white fur, black skin and a thick layer of fat under their skin.
Cactus – Cactus is a desert plant which has modified stems and leaves. It also has long roots that penetrate deep into the soil for absorption of water.
Weather – The day-to-day conditions of the atmosphere such as temperature, rainfall, wind etc. at a particular place is called weather.
Climate – A climate is the average weather of a particular place over years.
Habitat – Habitat is a natural place where organisms live. It provides food, water, shelter and space to survive . It consists of both biotic and abiotic factors.
Biome – A biome is a large biological community where different types of plants and animals live, they share common characteristics specific to that area.
Nocturnal –Nocturnal animals are the animals that hunt in the night and stay in their burrow during the day time.
Shrubs – Shrubs are the type of plants that are bushy and branch into a few thick stems at base. They are shorter than trees and larger than herbs.
Predator – Predators are the organisms that eat other animals. For example in case of a lion and deer, the lion is the predator that hunts the deer.
Prey – Preys are the animals that are being eaten by the predators. For example in case of a lion and deer, the deer is the prey which gets hunted by the lion.
Hooves – Hoof (Plural is Hooves) is the horny part of the foot found in animals such as mountain goats, horses, deer. Hooves help the animal to walk long distances on the rocky mountain surfaces.
Ecosystem – An ecosystem is a community of living organisms (biotic factors) like plants and animals that interact with each other and their environment (abiotic factors).
Biotic – Bios means life. Biotic things or factors include all living organisms. Examples include cats, trees, dogs etc.
Abiotic – Abiotic things or factors include all the non-living things. Examples include Table, pen, notebook etc
Streams – Stream is a flowing water body similar to a river but smaller and narrower in size.
Salinity – Salinity is the amount of salt dissolved in the water.
Saline water – If the water has a high concentration of dissolved salt in it, it is called saline water.
Terrestrial habitat – Terrestrial means land. Terrestrial habitats are ones that are found on land, like forests, grasslands and deserts.
Aquatic habitat – Aquatic refers to water. Aquatic habitat is a habitat with water bodies such as a river, lake, pond, sea and oceans.
Acclimatization – Small changes that take place in the body of an organism to get used to to changes in surroundings are called acclimatization. This takes place over short periods of time.
Adaptation – Adaptation is the specific features or the changes in behaviour and appearance that enable an organism to live in a particular environment (habitat), depending on the factors like temperature, availability of water etc. Adaptation takes place over thousands of years.
Blow holes – Nostrils of animals like whales and dolphins are called blow holes, they are involved in breathing and are located at the top or back of their head. Dolphins and whales do not have gills. They have lungs. They breathe air through their blowholes.
Adaptations in camel
- They have long legs to keep their body away from the hot sand.
- They excrete small amounts of urine and their dung is very dry.
- They have long eyelashes to protect their eyes in sandstorms.
- They are capable of losing very little water from their bodies and hence can survive without water for a long period of time.
Hump – Elevated fleshy structure on the back of a camel. Food is stored as fat in the hump. And hence the camel can go on without eating for months.
Adaptations in fish
- They have streamlined bodies to help them swim easier in water.
- Body is covered with slippery scales that protects them as well as assists them with easy movement under water.
- They have thin fins and a tail that helps in the change in direction and maintain balance during movement.
- Gills help in respiration.
Streamlined body – Streamlined body is the one which has pointed or narrow ends and the middle portion is wider. This streamlined shape of the body helps fish to swim easily without resistance from water and birds to easily fly without resistance from air.
Adaptations of desert plants
- The leaves in desert plants are either absent or are very small and form spines, to reduce loss of water through transpiration.
- Photosynthesis is usually carried out by stems.
- The stem is covered with a thick waxy layer which prevents the loss of water.
- Roots grow long and deep in search of water inside the ground.
Adaptations of high altitude plants. – The trees are cone shaped with sloping branches provided with needle-like leaves that helps water and snow to easily slide off.
Adaptations of aquatic plants
- Roots are highly reduced and their main function is to hold the plant in place.
- Only the flowers and leaves of some plants float on the surface of water to receive maximum sunlight.
- Submerged plants will have highly divided leaves that allow easy flow of water through them without damaging them.
- They are capable of living in both water as well as land. Adult frogs breathe through skin under water, and when on land they breathe through their lungs.
- They have strong legs that help them in leaping and webbed feet that help in swimming.
Why do we experience difficulty in breathing in higher altitudes and while doing physical exercises?
At higher altitudes like on mountains the availability of oxygen is less. So, we have to breathe more to supply the body with the amount of oxygen it requires. This causes difficulty in breathing.
Our body uses oxygen to breakdown food and release energy. When we do vigorous exercises, our body requires more energy. So more oxygen is required. So, to supply the body with the required amount of oxygen we breathe more. This causes difficulty in breathing.
Why do nocturnal animals like desert snakes, rats etc., come out only during the night?
Animals that are active during night are called nocturnal animals. Many desert animals are nocturnal to avoid the hot sun during the day time while the nights in deserts are cooler. They cannot get easily noticed in the night so they can easily escape from the predators.
Why do desert plants have spines?
In desert plants, leaves are modified into spines like in cactus to prevent the loss of water through transpiration and also to protect themselves from getting eaten by the herbivore animals of the desert.
Why do frogs and ducks have webbed feet?
Frogs are amphibians which live both on land and water. Aquatic birds like ducks, swans, penguins etc., spend most of their time in water. So, to help these organisms to swim easily in water, they have webbed feet, which act as paddles (the flat blades used in boats to move forward in water) and help in moving them forward.
Melanin – A pigment which is responsible for giving color to the skin, hair and eyes. It also protects our skin from the sun.
Why are people dark skinned ?
People in high temperature regions are exposed more to the sun and hence they have more melanin – to protect their skin from the sun. That is why they are dark skinned.
Digestion in housefly – The housefly vomits digestive juices and saliva onto the food material and sucks in the partially digested food
Digestion in dogs – They have a short digestive system because they feed on meat that has been dead for sometime. They digest and excrete within 6 hours. They have a short digestive system / digestion duration because if the meat stays in the digestive system for any longer the meat starts decaying and that is harmful for the dog.
Digestion in Rabbits
- The undigested food is stored as moist pellets in the small intestine of the Rabbit. It is acted upon by digestive enzymes and it gets partially digested. The pellets are excreted as faeces
- And it is consumed again by the rabbit to complete digestion.
Genes – They determine our physical characteristics – how we look etc.
Melanoma / skin cancer – if skin is exposed to sun for a long time it changes its genetic structure which leads to cancer.
Sweating is an adaptation, how ?
Human body temperature is 37 degree Celsius. And we are adapted to maintain this temperature by sweating. When the surrounding temperature is high and we feel hot, we sweat. This sweat evaporates and cools the body down.
Ecology – Ecology is the study of living organisms and their interaction with each other and with the environment.
Kangaroo rat – A nocturnal desert animal. It never drinks water but breaks down fat in the body and the hydrogen molecule in fat combines with oxygen and forms tiny amounts of water.
Spiny leaves – Cactus plants have long pointed spines (leaves are modified into spines) to reduce water loss due to transpiration.
Grassland – A biome which has large trees and carpets of grass.
- It is a biome which is covered with ice and it is the coldest and harshest biome.
- Plants in this region are short in height, to protect themselves from the wind. The leaves are leathery to store moisture and heat.
Countershading – In fishes, the upper body is dark colored and the lower body part is lightly colored. This happens so that the fish is camouflaged (blends with the colour) in the water and is protected from predators.
ADOLESCENCE – Adolescence is the transitional period between childhood and adulthood. It begins around the age of 10-11 and lasts until the age of 19. The period of adolescence is known as teenage. Besides the physical changes of puberty, adolescence is also a time of cognitive, social and emotional changes.
PRIMARY SEXUAL CHARACTERS – Primary sexual characteristics include the reproductive organs an individual is born with. Testes in male and ovaries in females.
PUBERTY – Puberty is the period of life during which a person attains reproductive maturity. During puberty, the person’s body undergoes changes – development of the reproductive organs and secondary sexual characteristics.
TEENAGE- The period of life between the ages 13 and 19 is known as the teenage years. It is also the period of adolescence – the transitional period between childhood and adulthood.
REPRODUCTIVE MATURITY/ SEXUAL MATURITY – Reproductive maturity is the ability of an organism to reproduce.
SEBACEOUS GLAND – It is a gland located in the dermis layer of the skin, which secretes an oily, waxy substance known as sebum.
DERMIS– The dermis is one of the layers of the skin.
SECONDARY SEXUAL CHARACTERS – Secondary sexual characteristics are those which emerge at puberty and help us differentiate a male and female by appearance. Change of body shape and height are some examples of secondary sexual characteristics.
ENDOCRINE GLANDS – Endocrine glands are known as ductless glands. They secrete hormones directly into the bloodstream. Eg: Adrenal glands, Thyroid, gonads
EXOCRINE GLANDS – Exocrine glands are glands with ducts that secrete substances/chemicals into a duct which reaches the target sites. Eg: Salivary glands, mammary glands
GAMETES – Gametes are also called sex cell/reproductive cells. They are distinct in males and females. The male gamete is called sperm whereas the female gamete is called ovum (Plural – Ova) or egg. Gametes are formed in the reproductive organs. During sexual reproduction, the male and female gametes fuse (fertilization) to form the zygote.
GROWTH HORMONE – Growth hormone is produced by the pituitary gland. It promotes the growth of individuals.
GIGANTISM – It is a growth hormone related disorder. It is the result of the excess secretion of growth hormone by the pituitary gland. In children it is known as gigantism wherein in adults this condition is called acromegaly.
DWARFISM – It is a growth hormone related disorder. It occurs due to insufficient secretion of growth hormone by the pituitary gland in children.
GOITRE – Goiter is a swelling of the thyroid gland that is visible in the neck region. Simple goitre is caused because of insufficient secretion of thyroxine which is a hormone produced by the thyroid gland.
HOARSE – When a person’s voice sounds rough and harsh, it is said that their voice is hoarse.
HORMONES – Hormones are chemicals that are secreted by the endocrine glands. They are also called chemical messengers. They are concerned with maintaining various body functions.
- Thyroxine hormone is secreted by the thyroid gland,this hormone maintains body metabolism.
- Insulin is secreted by the pancreas, this hormone maintains blood glucose levels.
INSULIN – Insulin is a hormone that is secreted by pancreas. It helps in maintaining the blood glucose level.
IODINE – Iodine is a mineral found in some foods. The body needs iodine to make thyroid hormone. This hormone controls the body’s metabolism and many other important functions.
MAMMARY GLAND – Mammary gland is an exocrine gland found in mammals. It is concerned with the production of milk after a young one is born in order to feed them.
MENARCHE – In girls, menstruation starts usually between the age of 10 to 15 when they attain puberty. The occurrence of menstruation for the first time is called menarche.
MENOPAUSE – The term menopause is used to describe the end of a woman’s menstrual cycle and the different changes a woman experiences. This marks the end of the reproductive phase of a female. Menopause happens after the age of 40 and may also vary from person to person.
MENSTRUAL CYCLE – Reproductive cycle involving a series of changes in the ovary and the uterus preparing for a possible pregnancy in a woman’s body every month is called the menstrual cycle.
MENSTRUATION – When the released ovum is not fertilized by a sperm, the egg, the inner lining of the uterus along with the blood vessels are shed periodically (once in 28 – 30 days). This is called menstruation and is a part of the menstrual cycle.
METAMORPHOSIS – The transformation of the larva into an adult through drastic changes is called metamorphosis. Frogs and insects are examples of organisms showing metamorphosis.
NUCLEUS – The nucleus is a double-membraned organelle that contains the genetic material.
OESTROGEN and PROGESTERONE – Oestrogen and progesterone are hormones produced by the ovaries. Progesterone plays an important role in the menstrual cycle and maintenance of pregnancy. Oestrogen is responsible for the development of secondary sexual characters and is also involved in maintaining the menstrual cycle and pregnancy.
OVARY – Ovaries act as the main female sex organs that produce the female gametes and various hormones. These organs are situated one on both sides of the lower abdomen.
OVUM ( EGG) – Ovum is the female reproductive cell (female gamete). Plural : Ova.
PIMPLE – Pimples are tiny bumps on skin caused due to the increased activity of the sweat and sebaceous gland.
ACNE – Acne is a skin condition in which the sebaceous glands get inflamed due to hormonal imbalance. This condition arises in most teenagers because of the hormonal changes in the body. It usually goes after the adolescence period.
ADAM’S APPLE – Adam’s apple develops during puberty and is prominent in males. It is visible as a protrusion in the throat due to the enlargement of the voice box.
VOICE BOX/LARYNX – Voice box, also called a larynx, is an organ situated in the neck region above the windpipe/trachea. It contains vocal cords which manipulate the pitch and volume of the voice.
ADDICTION – The term addiction is defined as a disorder characterized by uncontrollable drug seeking and use of it, despite its adverse consequences.
ADRENALINE – It is a hormone secreted by the adrenal glands. This hormone helps our body respond to stress by bringing about certain changes in the body like increasing the heart rate, raising blood glucose levels, etc. It is also called the ‘fight or flight’ hormone.
HIV – Human Immunodeficiency Virus (HIV) causes AIDS.
AIDS – Acquired immunodeficiency syndrome (AIDS) is a disease caused by the Human Immunodeficiency Virus (HIV). It is a chronic condition where the immune system of the person is severely damaged. It spreads through infected needles, sexual contact with the infected person, it is known to spread from infected mother to baby during pregnancy. AIDS does not spread through touch. There are many medications to manage the symptoms but currently, there is no cure for AIDS.
- The thread-like structure present inside the nucleus is called chromatin. Chromatin condenses to form the X-shaped structure called chromosomes ( looks like an ‘X’ ) during cell division. (Cell division is a biological process by which one cell divides into two or more cells).
- In human beings there are 46 (23 pairs) chromosomes. Each chromosome is made of proteins called histone and DNA (DNA-Deoxyribonucleic acid).
DIABETES – Diabetes is a disease in which the glucose levels in the blood will be high over a prolonged period of time. Insulin secreted by pancreas helps in reducing the blood sugar level. This disease occurs either when insulin is not produced in enough amounts or if the produced insulin is not utilised by the body effectively.
DNA – DNA (Deoxyribonucleic acid)is the genetic material in most organisms including human beings. DNA is present inside the nucleus which has information to make proteins in our body.
DRUGS – Drugs are chemical substances that are used as medication or in the preparation of medication. This term also refers to the substances that cause addiction.
SEX CHROMOSOME ( ALLOSOME) – In humans, a normal cell contains 23 pairs (46) of chromosomes. Out of these, one pair is sex chromosomes, which helps in the determination of the biological sex of an individual. They are named X and Y chromosomes. Male will have one ‘X’ and one ‘Y’ chromosome while a female will have 2 ‘X’ chromosomes.
SPERM – Sperm is the male reproductive cell (male gamete) produced by testes.
TESTES – It is the male reproductive organ which produces the male gametes (sperms). It occurs in pairs in humans. It also produces the male sex hormone – testosterone.
TESTOSTERONE – Testosterone is a sex hormone that is secreted by the testes. It is involved in the development of male reproductive organs and secondary sexual characteristics .
THYROXINE – Thyroxine is a hormone secreted by the thyroid gland. It maintains the balance of all metabolic activities. The deficiency of this hormone can cause swelling of the thyroid gland, leading to goiter.
Reproduction – Reproduction is the process of producing individuals of the same kind. It is important for the continuation of life on earth.
Growth – It refers to the increase in height or size of the body or body parts.
Childhood – It is the period in an individual’s life span when all the body parts are at their developing stage.
Growth spurt – Growth spurt is referred to as the sudden increase in growth of the body. It lasts for 2-3 years and is most active during the adolescence period.
Sweat gland – It is a gland located in the dermis layer of the skin, which secretes sweat.
Gonadotropin releasing hormone – GnRH – The Gonadotropin releasing hormone is produced by hypothalamus. It regulates the secretion of luteinizing hormone and follicle stimulating hormone from the pituitary gland.
Pituitary gland – The pituitary gland is an endocrine gland situated in the brain and is called a master endocrine gland. It produces hormones that instruct other glands to secrete their hormones, this is why it is also called ‘master gland’. It also secretes growth hormone which controls the overall growth of a person.
Luteinizing hormone and Follicle stimulating hormone – Luteinizing hormone (LH) and Follicle stimulating hormone (FSH) are collectively known as gonadotropins, which are secreted by the pituitary gland. LH and FSH control the sexual and reproductive characteristics in males and females.
Adrenal gland – The adrenal glands are endocrine glands that are situated right above the kidneys. Adrenal glands produce hormones like adrenaline.
Thyroid gland – Thyroid gland is a butterfly-shaped endocrine gland situated in the throat. It secretes a hormone called thyroxin. This hormone is important as it maintains the balance of all metabolic activities. The deficiency of this hormone can cause swelling of the thyroid gland, leading to goiter.
Gonads – Gonads are organs that produce gametes. In males, testes produce sperms (male gametes) and in females, the ovaries produce eggs (female gametes). They are also responsible for producing sex hormones (Eg: Estrogen and Teststerone).
Gendercide – Gendercide is the killing of individuals of a specific gender. This inhuman act is practiced in many parts of the world against female infants and this should be abolished.
Ovulation – Ovulation is the process of release of a mature egg from one of the ovaries, which happens every month.
CISCE, or the Council for the Indian School Certificate Examinations, is an independent, non-governmental organisation responsible for overseeing schooling in India. They are the ones responsible for the Indian Certificate of Secondary Education (ICSE) and the Indian School Certificate (ISC) exams in India (ISC).
In 1956, a proposal to establish an Indian Council to oversee the administration of the University of Cambridge Local Examinations Syndicate’s Examinations in India was approved at a meeting of the Inter-State Board for Anglo-Indian Education, leading to the formation of the Council for the Indian School Certificate Examinations (CISCE). It serves all of India, but is not backed by the government (unlike the CBSE and NIOS). The organization’s headquarters can be found in New Delhi.
Indian students who have just finished Class X take the Indian Certificate of Secondary Education (ICSE) Examination, a K–10 public board exam (equivalent to the first two years of the 4 year High School program). Candidates must enroll in seven subjects, of which three are electives and four are required.
Similar to that, students finishing Class XII take the Indian School Certificate (ISC) Examination, a K–12 public board exam (equivalent to the end of the 4 year High School program). Candidates may select three, four, or five further courses to take tests for after choosing [English language | English] as one of their subjects.
History of ICSE
- The University of Cambridge Local Examinations Syndicate founded CISCE (Council for the Indian School Certificate Examinations) in 1959. (now separated).
- The Council was established for the express aim of seeing to it that all national examinations are properly administered.
- The Council has final say over the content and format of these tests.
- They offer classes leading to certification in English language proficiency tests for students in grades 10 through 12.
- To make sure the curriculum is as up-to-date and focused on learning objectives as possible, the
- Council is constantly working to improve curricular frameworks and evaluation methods.
Students interested in attending a CISCE school must enroll in one of the CISCE-affiliated (English-medium) schools rather than apply directly to the organization. Except for the Indian language paper, all examinations will be in English. A separate pass certificate is issued after each exam with letter grades according to the marks earned (like almost all other Indian educational boards). Keep in mind that the Central Board of Secondary Education (CBSE) and the Council for the Indian School Certificate Examinations (CISCE) are not the only options for Indian students entering high school.
Benefits of ICSE
Curriculum: The International Certificate of Secondary Education (ICSE) uses a comprehensive curriculum with a small number of required courses and a vast range of electives. There are three primary categories for ICSE subjects. It is meant to instill in students a capacity for problem-solving.
Global Exam: The board provides excellent training for competitive exams around the world, ensuring that its students are ready to compete with the brightest brains in the world.
Training Programm: In order to ensure that all educators have access to high-quality training and support, the CISCE runs a number of online programmes. Teachers will receive guidance on pedagogical issues, new methods of instruction, revised curricula, and the administrative abilities necessary to provide their pupils with a high-quality education.
Teaching Methods: Rather than focusing solely on theoretical principles, the ICSE priorities practical training through an application-based teaching technique. The analytical abilities of its students are improved.
Subjects Offered in ICSE
Group 1 (Compulsory Subjects)
Group 2 (Optional Subjects)
Group 3(Optional Subjects)
Physics, Chemistry, Biology
History,Civics and Geography
Modern foreign language
One Classical Language
Mass Media and Communication
Modern Foreign Language
Question 1. What was the plea of Nana Saheb, the adopted son of Peshwa Baji Rao-II?
Answer – Nana Saheb pleaded that he be given his father’s pension when the latter died.
Question 2. How did the Company plan to bring an end to the Mughal dynasty?
Answer – The name of the Mughal king was removed from the coins minted by the Company.
Question 3. Why were the Indian sepoys unhappy with the British rule? Give any one reason?
Answer – The Indian sepoys were underpaid
Question 4. What rumour spread among the sepoys of the Meerut regiment about the new cartridges?
Answer – The rumour spread that the new cartridges were coated with the fat of cows and pigs.
Question 5. What did the ageing Mughal emperor Bahadur Shah Zafar do after he was declared the leader of the rebels?
Answer – He wrote letters to all the chiefs and rulers of the country to come forward and organize a confederacy of Indian states to fight the British.
Question 6. Name any two smaller rulers who acknowledged the suzerainty of Bahadur Shah Zafar.
Answer – Nana Saheb and Biijis Qadr.
Question 7. Who was Tantia Tope?
Answer – He was the General of Nana Saheb.
Question 8. Who was Ahmadullah Shah? What was his prophesy?
Answer – Ahmadullah Shah was a maulvi from Faizabad. His prophesy was that the rule of the British would soon come to an end.
Question 9. Who was Bakht Khan?
Answer – Bakht Khan was a soldier from Bareilly. He took charge of a large force of fighters who came to Delhi.
Question 10. When did the British recapture Delhi?
Answer – The British recaptured Delhi in September 1857.
Question 11. Why were the powers of the East India Company transferred to the British Crown?
Answer – The powers of the East India Company were transferred to the British Crown in order to ensure a more responsible management of Indian affairs.
Question 1. Under what pretext did the Company take over Awadh?
Answer – In 1801, a subsidiary alliance was imposed on Awadh, and in 1856, it was taken over. Governor-General Dalhousie declared that the territory was being misgoverned and British rule was needed to ensure proper administration.
Question 2. How did the Company plan to bring an end to the Mughal dynasty?
Answer -(a) First of all the name of the Mughal king was removed from the coins minted by the Company.
(b) In 1849, Governor-General Dalhousie announced that after the death of Bahadur Shah Zafar, the family of the king would be shifted out of the Red Fort and given another place in Delhi to live in.
(c) In 1856, Governor-General “Canning decided that Bahadur Shah Zafar would be the last Mughal king and after his death his descendants would be known as princes.
Question 3. Why were the Indian sepoys in the employ of the Company discontented? Give sufficient reasons.
Answer – Reasons for their discontentment:
(a) The Indian sepoys were given poor salaries and allowances.
(b) The conditions of service also made them unhappy.
(c) Some of the new rules even violated their religious sentiments and beliefs.
(d) Those were the days when many people in the country believed that if they crossed the sea they would lose their religion and caste. So when in 1824 the sepoys were told to go to Burma by the sea route to fight for the Company, they refused to follow this order. As a result, they were given severe punishment. What is more, in 1856, the Company passed a new law which stated that every new person who took up employment in the Company’s army had to agree to serve overseas if required.
Question 4. What reforms did the British introduce in the Indian society? How did the people of India respond to them?
Answer – The British introduced several reforms:
(a) They passed laws to stop the practice of sati and to encourage the remarriage of widows.
(b) They promoted English language education.
(c) In 1850, the Company passed a new law that made the conversion to Christianity easier.
Many Indians began to feel that the British were destroying their religion, their social customs and their traditional way of life. But at the same time there were other Indians who readily accepted the reforms introduced by the British. In fact, they wanted to change existing social practices.
Question 5. Why did the chiefs and rulers support the Mughal emperor Bahadur Shah Zafar in the revolt?
Answer – The Mughal dynasty had ruled over a large part of the country. Most smaller rulers and chieftains controlled different territories on behalf of the Mughal ruler. Threatened by the expansion of British rule, many of them felt that if the Mughal emperor could rule again, they too would be able to rule their own territories once more, under the Mughal authority.
Question 6. How did the British try to win back the loyalty of the people after they recaptured Delhi?
Answer – (a) The British announced rewards for loyal landholders by allowing them to continue to enjoy traditional rights over their lands.
(b) Those who had rebelled were told that if they submitted to the British and if they had not killed any white people, they would remain safe and their rights and claims to land would not be denied.
Question 7. What was the condition after recapturing of Delhi by the British?
Answer – The recapturing of Delhi did not mean that the rebellion died down, people still continued with the resistance and battle with the British. The British had to fight for two years in this manner to suppress the massive forces of popular rebellion.
The Central Board of Secondary Education (CBSE) is a Board of Education for public and private schools that falls under the Ministry of Human Resource Development (MHRD) (formerly the Ministry of Education) of the Government of India. It is a Government Board of Education that was established on November 3, 1962, with the primary aim of creating a uniform standard and foundation for all students in the nation.
The CBSE is a national board of education for schools. It has the power to accredit schools, run the Secondary School Examination and the Senior School Certificate Examination, and give out certificates.
It works to provide a teaching methodology and atmosphere that equips the next generation of people to lead the growing knowledge society on a global scale. The Board places a strong emphasis on the overall development of students by offering a stress-free learning environment that will produce competent, self-assured, and entrepreneurial citizens who will uphold peace and harmony.
The main goals were to better serve educational institutions and to respond to the educational needs of children whose parents held frequently-transferable positions in the Central Government.
CBSE motto is “Asto ma Sad gamay” (असतो मा सद्गमय ) – “O God ! Please lead me towards truth from untruth”.
History of CBSE
The Indian government established the “Board of High School and Intermediate Education, Rajputana” in 1929. Ajmer, Merwara, Central India, and Gwalior were among the cities included. It was later restricted to Ajmer, Bhopal, and Vindhya Pradesh. It was renamed the “Central Board of Secondary Education” in 1952.
Every year in March, CBSE gives the final exams for Class 10 and Class 12 students. By the end of May, people will know what the results are. Before, the board ran the AIEEE Exam, which students took to get into engineering and architecture programmes in India’s colleges. But in 2013, the AIEEE test was combined with the IIT-Joint Entrance Exam (JEE). The common test is now called JEE (Main), and it will be given by the National Testing Agency from now on.
CBSE Regional Offices
- Delhi: Covering NCT of Delhi and Foreign Schools.
- Chennai: Covering Andaman and Nicobar Islands, Andhra Pradesh, Daman and Diu, Goa, Karnataka, Maharashtra, Puducherry, Tamil Nadu and Telangana.
- Guwahati: Covering Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura.
- Ajmer: Covering Dadra and Nagar Haveli, Gujarat, Madhya Pradesh and Rajasthan.
- Panchkula: Covering Chandigarh, Haryana, Himachal Pradesh, Jammu and Kashmir and Punjab.
- Allahabad: Covering Uttar Pradesh and Uttarakhand.
- Patna: Covering Bihar and Jharkhand.
- Bhubaneswar: Covering Chhattisgarh, Odisha and West Bengal.
- Thiruvananthapuram: Covering Kerala and Lakshadweep.
- Dehradun: Covering Uttar Pradesh and Uttarakhand.
Objectives of CBSE
- To define appropriate approaches of academic activities to provide stress free, child centered and holistic education to all children without compromising on quality
- To analyze and monitor the quality of academic activities by collecting the feedback from different stakeholders
- To develop norms for implementation of various academic activities including quality issues; to control and coordinate the implementation of various academic and training programmes of the Board; to organize academic activities and to supervise other agencies involved in the process
- To adapt and innovate methods to achieve academic excellence in conformity with psychological, pedagogical and social principles.
- To encourage schools to document the progress of students in a teacher and student friendly way
- To propose plans to achieve quality benchmarks in school education consistent with the National goals
- To organize various capacity building and empowerment programmes to update the professional competency of teachers
- To prescribe conditions of examinations and conduct public examination at the end of Class X and XII. To grant qualifying certificates to successful candidates of the affiliated schools.
- To fulfill the educational requirements of those students whose parents were employed in transferable jobs
- To prescribe and update the course of instructions of examinations
- To affiliate institutions for the purpose of examination and raise the academic standards of the country.