Class 9th ICSE

The Human Digestive System * The alimentary canal includes organs such as the mouth, pharynx, oesophagus, stomach, small intestine, large and anus. * The mouth, the anterior opening of the alimentary canal, leads intestine the buccal cavity or oral cavity, which contains the teeth and the tongue. * The tongue helps push the food from ... Read more

* Solid food is broken down in teeth to smaller, absorbable matter with the help of teeth. * There are four types of teeth – incisors, canines, premolars and molars. * Herbivores do not have canines, because of which there is a gap between the incisors, and the premolars. * Carnivores have all the four ... Read more

Components of Food – Nutrients and Balanced Diet * Carbohydrates, fats, proteins, vitamins and minerals are various nutrients needed by our body. * Carbohydrates provide energy to the body to perform various activities. * Wheat, rice, potato, sugarcane, mango, melon and banana are some sources of Carbohydrates. * Fats provide energy and warmth to the ... Read more

* Many fungi are eaten as food and cultivated on a commercial basis. * Yeast is a source of Vitamin B complex and Riboflavin. * Yeast help in the making of bread, tradition food item like idli – dosa, dhokla and khaman, as well as alcohol. * Aspergillus and Penicillium are also used to produce ... Read more

Nitrogen Fixation * Some micro organisms reside in the root nodules of leguminous plants. They can fix nitrogen from the air into the soil, and increase soil fertility. * Some bacteria and blue green algae present in the soil fix nitrogen from the atmosphere and convert it into nitrogenous compounds. * Some micro organisms decompose ... Read more

Classification of Living Organisms * A process of gradual and progressive change or development in characteristics is known as evolution. * Organisms are grouped at various levels: Kingdom, Phylum for animals or Division for plants, class, Order, Family, Genus, and species. * Kingdom Protista includes unicellular eukaryotic organisms, the simplest of the eukaryotes. * Kingdom ... Read more

Respiration in Plants * Respiration provides oxygen, which is used for the oxidation of food to provide energy. * Plants respire through small opening called the stomata on leaves and lenticels o stems and roots. * Cellular respiration involves breakdown of the C – C bonds of compounds of food. It takes place in the ... Read more

The Fruit and the Seeds *Once fertilisation takes place in a flower, the ovary ripens to form the fruit, while the ovules for the speeds. * A fruit, when formed without fertilisation of the ovary is called a parthencarpic fruit. * Typically, a fruit is made up two parts – the pericarp and the seeds. ... Read more