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Light

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 Laws of Reflection Reflection Light gets reflected off surfaces. Any surface that is really well polished or shiny acts as a mirror. The phenomenon of light bouncing off surfaces is called reflection. Laws of reflection The ray of light that strikes a reflecting surface is called as the incident ray and the ray that gets reflected back is called the reflected ray. The imaginary line that is perpendicular to the reflecting surface is called the normal. The angle of incidence ∠i is the angle between the incident ray and the normal. The angle of reflection ∠r is the angle between the reflected ray and the normal. Laws of Reflection: Angle of incidence ∠i is always equal to the Angle of reflection ∠r (∠i=∠r). The angle of incidence, the angle of reflection and the normal all lie on the same plane. To know more about Laws of Reflection, visit here. Ray diagram The path taken by a narrow beam of light is depicted as a ray diagram. Regular and diffused reflection
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Chapter 1st

 Chemical Reactions and Equations
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  Ecosystem Mode of nutrition in animals and plants Autotrophic and Heterotrophic Saprophytes and decomposers Saprophytes are plants, fungi and microorganisms that feed on the dead and decaying material. Decomposers break down the organic matter or waste material and release nutrients into the soil.  For example, bacteria, worms, slugs, and snails. Abiotic components Non living chemical and physical components of the environment like the soil, air, water, temperature, etc. Biotic components Living organisms of the environment like the plants, animals, microbes and fungi. Ecosystem Includes both biotic and abiotic components. In a given area, all the living things such as plants, animals and organisms interacting with each other, and also with their non-living environments, i.e., weather, earth, sun, soil, climate, atmosphere. Trophic levels It refers to the various levels in a food web as per the flow of energy. The different trophic levels are – Producers (T1) Primary consumers (herbi
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  Heredity Sexual reproduction The mode of reproduction that involves two individuals; one male and one female. They produce sex cells or gametes which fuse to yform a new organism. Genes Gene is the functional unit of heredity. Every gene controls one or several particular characteristic features in living organisms. Heredity The process by which the features of an organism are passed on from one generation to another is called heredity. The process is done by genes, which define the characters in the organism. Mendel’s work Gregor Johann Mendel, known as ‘Father of Genetics’, was an Austrian Monk who worked on pea plants to understand the concept of heredity. His work laid the foundation of modern genetics. He made three basic laws of inheritance – The Law of Dominance, The Law of Segregation and The Law of Independent Assortment. Dominant traits The traits that express themselves in an organism in every possible combination and can be seen are called Dominant traits. In Mendel’s exp
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How do Animals reproduce

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Reproduction :-    Ability to produce new organism is known as reproduction. There are two types of reproduction-asexual reproduction and sexual reproduction. Different types of Reproduction There are mainly two types of reproduction- asexual reproduction and sexual reproduction. Asexual Reproduction It is a mode of reproduction involving single parent. There are different modes of asexual reproduction- Fission:- It is the process of splitting of cell into two or more different cells. It can be categorised into two ways. Binary fission and Multiple  Fission. Binary fission is defined as the splitting of the organisms into two equal halves and each half give rise to a new organism.    For example,  Amoeba , Paramisium, Hydra, Yeast, etc. The most common type of fission in binary fission.  Fig.1. Binary fission in  Amoeba Multiple Fission If a   cell splits into number of cells called as multiple fission.  Fragmentation is another mode of asexual reproduction in which organism breaks
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Control and Coordination

  Control and Coordination Systematic working of the various organs of an organism (plants or animals) producing a proper response to the stimulus is called co-ordination. Coordination in Plants Not so elaborate, controlled by phytohormones and external stimulus. Phytohormones •   Control and coordination in plants is done by phytohormones. •   They are naturally occurring chemical substances which control one or other aspect of growth. •   Auxin – Cell enlargement and differentiation. •   Gibberellins – In presence of auxin, promotes cell enlargement and differentiation. •   Cytokinins – Promotes cell division, opening of stomata, etc. •   Abscisic acid – Closing of stomata, wilting and falling of leaves, etc. Tropic Movements •   Directional plant growth movement in response to an external stimulus. •   Growth of a plant may be towards the stimulus (positive tropism) or away from it (negative tropism). •   Phototropism – movement in response to light. •   Chemotropism – in response t
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