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CBSE Class–VI
Subject Science
Revision Notes
CHAPTER – 9 The Living Organisms and Their Surroundings The surroundings where plants and animals live are called their habitat. Several kinds of plants andanimals may sharethe same habitat. The presence of specific features and habits, whichenable a plantor an animal to live ina particular habitat, is called adaptation. There aremany types of habitats, however, these may bebroadly grouped asterrestrial (on theland) and aquatic (in water). There is awide variety oforganisms present indifferent habitats. Plants, animals and microorganisms together constitute biotic components. Rocks, soil, air,water, light andtemperature are someof the abiotic components of oursurroundings. Characteristics of living things: They need food, air and water to grow and for the other processes. The youngones grow intoadults. They respire. Animals breathe in oxygen and breathe out carbon dioxide. Plants take in carbon dioxide and give outoxygen. They respond to changes in the surrounding (stimuli). They all get rid of wastes produced in the body (excretion). They reproduce their own kind. They have a definite lifespan. They have a particular structure and are made up of cells. Theyshow movement. Habitat: Habitat isthe place where an organism findscomfort, safety, food, water, air, shelter andsuitable conditions forbreeding and survival. It has twocomponents biotic (living things like plants and animals abiotic (non-living
things like rocks, soil, air andwater). BIOTIC COMPONENTS 1. AUTOTROPHS AUTOTROPHS MAKETHEIR OWN FOOD( AUTO MEANS SELF; TROPH MEANSNUTRITION.) green plants areautotrophs. 2. HETEROTROPHS ( HETERO MEANS DIFFERENT OR OTHERS; TROPH MEANS NUTRITION ) . Herbivores: plants and grass eating animals. Carnivores: flesh or meat eating animals Omnivores; eat both, plants and the flesh. Habitat provides almost everything to an organism which is needed byit. ABIOTIC COMPONENTS light, temperature, water, humidity andrain, soil, air and wind, height ofa place-plains orhills. Type ofHabitat: (a) Terrestrial Habitat: Plants and animals live on land. some terrestrial habitats are seashore or the coastal area. Ex. lants like mangroove and coconut palm are common. on thebank of Ponds and lakes. Ex. frog,turtle,alligator, crocodile,duck etc.
life on land. Ex. cat,deer,lion,tiger,cow. Plants growing on land under normal conditions of moderate temperature and availability of water arethe mesophytes. desert habitat on land . Ex. cactus,euphorbia,aloe,lizards,snake,camel. underground habitats. Ex. moles, beetle, cricket, termite, milliped, ant. plants and animals living on hills and mountains.Ex. yak, bear, hill goat, flying fox. plants in hills are mostly conical and evergreen. they bear deep growing roots. the stem is woody, bearing needle-like leaves.plants are mostly xerophytes. Ex. apple,pear,plum,apricot,walnut,almond. high snowypeaks and polarregions.Ex, polar bear(white bear), penguin arboreal or areial habitat Arbor means a tree.organisms living on trees arearboreal.Ex. was a honey bee,sider, owls, birdsand numerous insects. (b) Aquatic Habitat: Plants andanimals live inwater. Example: ponds, swamps, lakes, rivers and oceans. plants growing in water arecalled hydrophytes. plant bodyis covered witha slippery substance called mucilage. Adaptations: Presence ofspecific features orcertain habitats which enable an organism to live inits surrounding. Adaptation helpsan organism inacquiring certain characteristics which helps it inbeing able tolive in thehabitat of itschoice. The adaptation maybe (i) related to the habitat, or (ii) related to its bodystructure. Terrestrial: (a) Deserts: Small animals stayin burrows deepin sand during the day, andcome out atnight. In plants, leaves are either absent or verysmell as spines; stem has a thick waxy coating; roots godeep into thesoil. (b) Mountains: Animals have thick skin or fur;mountain goat hasstrong hooves. Treesare cone shaped having sloping branches; leaves are needle like. (c) Grasslands: Animals are lightbrown in colour; Lion: a Long clause infront legs thatcan
be withdrawn inside the toes; eyesin front of face. Deer: Srong teeth, long ears,eyes on the sides ofhead. Aquatic: (a) Ponds: · Plants withroots fixed insoil: Stems arelong, hollow andlight; leaves float on water. · Plants withroots submerge: Leaves are narrow andthin ribbon-like. (b) Oceans: organisms living in seaare called themarine plants and marine animals. Animals have streamlined body; gills to respire (dolphins and whales have blowholes). Animals likesquids and octopus do no havestreamlined body andstay deep inwater.
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