Notes

Epithelial Tissues * Animal tissues are broadly classified into four types, namely epithelial connective, muscular and neural. * Epithelial cells are compactly arranged with little intercellular matrix. * The epithelium and other tissues have three types of specialised junctions, namely tight, adhering and gap junctions. * Simple epithelium consists of a single layer of cells ... Read more

Meristematic Tissues * There are two main types of plant tissues- meristematic tissues and permanent tissues. * The specialised region in plants where meristematic tissues are present is known as the meristem. * There are two basic types of meristems-primary and secondary. * Primary meristem can be further divided into apical meristem and intercalary meristem. ... Read more

Roots of Flowering Plants * Roots provide proper anchorage to plants, synthesis plant growth regulators and help in the absorption of water and minerals from the soil. * The primary root and its branches comprise the tap root system, which is mostly found in dicotyledonous plants. * A quality certification scheme for food is being ... Read more

Basis of Animal Classification * Animals are classified on the basis fundamental features such as level of organisation, symmetry, cell organisation, nature of coelom, segmentation and notochord. * Level of organisation is the first basic fundamental feature by which animals are classified. There are four main types of cell patterns: cellular, tissue, organ and organ ... Read more

Algae * Algae are simple, thalloid, chlorophyll-bearing organisms found in fresh and marine water, moist stones, soils and wood. * Algae can be unicellular, colonial or filamentous. * Based on the type of pigment and the type of stored food we can classify algae into Chlorophyceae, Phaeophyceae and Rhodophyceae. * Chlamydomonas, Volvox, Spirogyra, are some ... Read more

Biological Classification System * The first classifications were made to identify organisms that were useful to man for food, shelter and clothing. * Aristotle devised the first scientific method of classification. * Later, Carl Linnaeus came up with the two kingdom system of classification. * All plants were put in the Kingdom Plantae while all ... Read more

Characteristics of living organisms * Living organisms display certain characteristics. * Growth and reproduction are the non-definitive characteristics of living organisms. * Metabolism and cellular organisation are considered to be the definitive characteristics of living organisms. * Living organisms, whether unicellular or multi-cellular, grow due to cell division. * Both unicellular and multi-cellular organisms reproduce. ... Read more