class 10th

Properties of antibiotics for medicinal use

  1. Antibiotic should have quick and broad spectrum therapeutic effect should Kill variety of microorganisms.
  2. It should not cause side effects in the host e.g. nervous disorders, allergies, Indigestion etc.


Bioactive molecules are those organic compounds which are produced on Commercial scale by the microbes and are useful in the human welfare. These Include organic acids, enzymes, alcohols, etc.

Other Bioactive Molecules

  1. Cyclosporine.
  2. Vitamins.


  1. Production of curd, yoghurt and butter milk.
  2. Curd. It is produced by the bacterial fermentation of milk. Bacteria involved in curd formation are Lactic acid bacteria (LAB) which include Lactobacillus acidophilus. Lactis and streptococcus lactis.

importance of phosphorus cycle

Phosphorus is a major constituent of biological membranes, nucleic acids and cellular energy transfer system(ATP) Animals need phosphorus to make shell, bones and  teeth. Reservoir pool of phosphorus is the rock, which  contain phosphorus in the form of phosphates.

During weathering of rock small amount of  phosphates dissolved in soil solution and are absorbed by the roots of the  plants. Herbivore and other animals obtain organic form  of phosphorus from plants.

The waste product and dead organisms are  decomposed by phosphate-solubilising bacteria releasing phosphorus.

How phosphorus cycle differs from carbon cycle?

There is no respiratory release of phosphorus  into atmosphere. Atmospheric inputs of phosphorus through  rainfall are much smaller. Gaseous exchange of phosphorus between organism  and environment are negligible.


Such strategies include establishment of botanical gardens, zoos, conservation Strands and gene, pollen, seed, seedling, tissue culture and DNA banks. These Facilities not only provide housing and care for endangered species, but also have educational values for the society.

  • Seed gene bank or germplasm bank.
  • Field gene bank.
  • Cryopresevation.
  • Botanical gardens.
  • Zoos.


  1. It stops the natural evolution and adaptations processes. In cryogenic Preservation of specimens, adaptations processes come to halt altogether.
  2. EX-situ conservation strategies are highly expensive.
  3. If fails to recreate the habitat as a whole. A species may adapt to change environmental conditions due to genetic variation of a species, its symbiotic counter parts or other elements.
  4. Seed banks are not effective for few plant species with recalcitrant seeds do not show viability for long time.

The aims of CBD are:

  1. To conserve the biodiversity.
  2. To use the biodiversity and its components in a sustainable way.
  3. Equitable distribution of benefits of biodiversity.

Following 10 biogeographical regions have been identified in India:

  • Trans-Himalaya with 2 provinces.
  • Himalaya with 4 provinces.
  • Desert (Kutch and Thar) with 2 provinces.
  • Semi-arid zone with 2 provinces.
  • Western –Ghats with 2 provinces.
  • Deccan peninsula with 5 provinces.
  • Gangetic plain with 2 provinces.
  • North East India with 2 provinces.
  • Indian Islands with 2 provinces.
  • Marine coasts with 3 provinces.
  • India as biocentre of origin of cultivated plants

India is one of the 12 centres of origin of cultivated plants.India has been considered as the origin place of 167 cultivated plant species and more than 320 their wild relatives.India is centre of origin of 30,000-50,000 varieties of rice,sugarcane,turmeric,ginger,mango,pigeon-pea etc.

  • World heritage sites

India is home to 5 worldheritage sitesand 6 Ramsar wetlands,amongst the protected areas.Heritage sites are the places that attractTourists. SUNDERBAN NATIONAL PARK, NANDA DEVI NATIONAL PARK, KEOLODEO GHANA NATIONAL PARK, MANAS WILD LIFE SANCTUARY & KAZIRANGA NATIONAL PARK.

  • There are 33 Botanical Gardens,89 National parks, 492 Wildlife sanctuaries and14 biosphere reserves in India.
  • There are about 47,000 species of plants and 81,000 species of animals identified in India. About 60% of the above diversity has been reported from Western Ghats, which is one of the hot spots of diversity in India.Out of the Above 81,000 animals’ species recorded from India.372 are mammals,1228 areBirds,428 reptiles,200 amphibians,2550 fishes,about 57,000 insects and5025Molluses and many other species of invertebrates.

Living resources conservation has three specific objectives:

  1. To maintain essential ecological processes and life support system.
  2. To preserve biological diversity.
  3. To ensure that any utilization of species and ecosystems is sustainable.

Biological diversity includes two related concepts,genetic diversity and ecological diversity.Genetic diversity is the amount of genetic variability among individuals of a single species as also between species.


Biodiversity has great importance to mankind due to its many uses:

  1. Ecosystem (ecological) role of biodiversity.
  2. Scientific importance.
  3. Drugs and medicine about 75% of world’s population depends upon plants or plant extracts for medicines. Some examples of drugs and medicenes extracted from plants are:
  4. Morphine(papaveysomniferum) is used as analgesic.
  5. Quinine(chinchonaledgeriana) for treatment of malaria.
  6. Taxol extracted from bark of Taxusbrevifolia and T.baccata is used as anticancer drug.
  7. Penicillin used as antibiotic is derived from a fungus called penicillium.
  8. Tetracycline is got from a bacterium.
  9. Digitalin a drug used for cure of heart ailments is got from digitalis.

Plants are also useful for making many synthetic products called botanochemicals.Twenty five % of drugs in pharmacy are got from only about 120 species of plants.About seventy five % of anticancer drugs are derived from plants found in tropical rainforest.

  • Food

One of the most fundamental values of bio-diversity is in providing food.

  • Industrial importance.

Wildlife is a renewable source and is beneficial to mankind in many ways.

  • Fur,skin and other products like leather,honey,lac,cochineal(a redpigment),guano,pearls,etc.obtained from wild animals are sources of trade.
  • Lvory of elephants,horns of rhino,antlers of deer,etc. fetch large amount ofmoney in foreign currency market.In fact, tourist industry of Kenya is based onits wildlife.


Extinction is the complete elimination of a wild species.It is anatural but slowProcess but due to unplanned activities of man. The rate of decline of wild life has been particularly rapid in the last one hundred years.India alone has a totalof 459 threatened species of which include 86 mammals,70 birds,25 reptiles, 3 amphibians, 8 fishes,23 invertebrates and 244 plants.There are a number of causes which are known to cause extinction of wildlife.

  1. Destruction of habitats and fragmentation: It is the most serious threat to wildlife. It is due to:
  2. Pollution due to automobiles,etc.leading to degradation of a number of important habitats.
  3. Deforestation leads to decrease in the area of movement so decreasing theirreproductive powers.In Tripura,deforestation of dense forests is posing a serious threat to the precious barbe’s leaf monkey,better known as spectacledmonkey,or Lajvanti Bandar,(shy-monkey).
  4. Soil erosion.
  5. Agricultural expansion.
  6. Overgrazing.
  7. Forest fires due to certain human activities or by chance.
  8. Indiscriminate hunting for various uses of animals,like food,hide,musk,tuskHorn,fur,plumage,recreation,etc.Other causes of indiscriminate hunting of wild Animals are: their increased demand as museum specimens and increased trade for the animal products like hides,skins,fur,leather,feathers,horns,ivory,meat etc.Excessive hunting is known to cause.
  9. Extinction of Dodo bird.
  10. Extinction of Cheetah.

what are soil and its important


Edaphic factors include all those factors which are related to the structure and composition of soil including its physical and chemical properties. Soil is the surface layer of land. Soil is not a single factor but is a complex of several

Soil factors, which together constitute the soil complex.  with the exception of parasites and epiphytes, all plants are dependent directly on the soil for mechanical anchorage and minerals and water supply. According to schimper’s second law, the distribution of plants in a region is determined chiefly by nature of soil directly or in relation to other factors. These include:

Soil formation: The soil formation occurs in two stages:

Weathering of rocks: It may involve chemical weathering due to hydration, hydrolysis, carbonation, oxidation-reduction or chelation of rock material physical weathering due to heating and cooling wetting, and drying, freezing, glaciations and action of wind (sand blasts),or biological weathering by bacteria, fungi and lichens due to their acids.

Pedogenesis: In this, the weathered mineral matter and the decomposed organic matter undergo biochemical, biophysical and geochemical changes to from the fully developed true soil. So the process of soil development is called pedogenesis. Pedognesis is more active in superficial layer of earth.

Soil types: On the basis of its formation, the soils are classified into two major Categories:

Residual soils: These are formed by weathering and pedogenesis of the rock.

Transported soils: transported by various agencies and are of four types: Alluvial soils: Transported by water.

  • Colluvual soils: Transported by gravity.
  • Eolian soils: transported by air.
  • Glacial soils: transported by slipping of glaciers.

Types soil particles

These particles vary in size and on the basis of soil particles and divided into following categories:

Gravel–more than 2 mm

Coarse sand–2 to 0.2 mm

Fine sand–0.2 to 0.02 mm

Silt–0.02 to 0.002 mm

Clay–less than 0.002 mm

what are importance of organism and population


Habitat is a specific physical place or locality occupied by an organism, population or community which has a particular combination of abiotic or environmental factors.


It is the sum total of environmental factors which determine the existence of an individual, population or community in a particular locality. Animals generally show habitat specificity with a few exceptions e.g. Hilsailisha(Indian shad) can live in both fresh-water and sea water.

It is generally occupied by the entire community e.g. a pound with many individuals of different species showing cohabitation.

Variety of habitats

Annelid Tubifex is found in running and well aerated fresh-water bodies with abundant organic matter. Plasmodium (malaria parasite) found in RBCs and liver cells of man, and in stomach and salivary glands of female Anopheles mosquito.

Oryctolagus(rabbit) found in the grasslands and open woodlands. Scoliodon(Indian shark) found in the sea all along the Indian coast.

Reasons for differential habitats

Rotation of earth around the sun and tilt of its axis are responsible for annual Variations in the intensity and duration of temperature, resulting in distinct seasons. The annual temperature and precipitation variations, in turn, result the formation of different types of biomes.


Subdivisions of a habitat having different environmental conditions and different kinds of organisms are called microhabitats e.g. forest floor, tree canopy, muddy bottom, surface of a pond, burrow, center of a pond etc.

Ecological Niche

Elton (1927) defined the ecological niche as “Anecological niche refers to animals Place in the biotic environment and its relation to its food and enemies or its functional role in an ecosystem”. In other words, if habitat is the address of an organism then ecological niche is the Profession of an organism. It is also called “way of life”. Examples: O. Neill (1967) reported seven different species of millipedes in forest floor of a maple oak tree. All these seven species are found in same habitat (e.g. forest floor) and belong to same trophic level.

Conclusion: This shows that no two species can occupy the same ecological niche. If they do occur in the same geographical area, and then they use different food items or are active at different times or are occupying somewhat different niches. In case, two different species found in same ecological niche, then only one survives while other is excluded.

Significance: Ecological niche helps in avoiding continuous intense competition for the place of living. It also helps in diversification of species into sub-species.


Organization is the arrangement of smaller components of any structure into larger ones and so on in a hierarchy or a pyramid in which components of each level coordinate with one another towards a common function.

Molecular organization is found in one-celled protozoan’s e.g. Amoeba, Paramecium, etc. which show the division of labour at the level of cell-Organelles.

Individual level of organization(Biological hierarchy)

In multicellular organisms, division of labour is at the level of tissue or organ level. In such organisms though each cell type is specialized for a specific function but no Cell can show independent existence and the cells show interdependence.

Cells          Tissues           Organs         Organ Systems         Organism.

Higher level of organization(Ecological hierarchy)

Ecological hierarchy includes a graded series of ecological categories of ecological hierarchy. Ecological hierarchy involves the following categories. Organism, Population, Species, Biotic community, Ecosystem, Biome and Biosphere


All organisms, including plants are not independent of themselves but depend upon some sort of surrounding medium known as environment. There is a continuous Interaction between the organisms and the environment. The environment can be defined as the sum total of all the physical and biotic conditions which influence the responses of organisms. The place where the organism lives is called its habitat, while the conditions and Resources for its life activities constitute the environment.


Ecological factors are those components of environment which determine the Variation in the physical and chemical nature of different habitats. These ecological factors are classified into two major groups.

Direct factors: These factors influence the organisms directly e.g. light, temperature, humidity, soil, moisture, soil nutrients and soil air etc.

Indirect factors: These factors affect organisms indirectly by modifying other factors e.g. soil structure, precipitation, wind, soil organisms, altitude, slope etc.


These include the non-living physico-chemical factors of environment. These are divided into the following categories: Climatic Factors & Edaphic Factors.

Climatic Factors (weather): These include the physical factors of environment like Light, Temperature, Humidity, Wind, Rainfall, Water & Atmospheric gases.

CLIMATIC FACTORS: Climate is average weather of an area. Climate is of two types: Microclimate and Macroclimate.

Microclimate: It represents the climatic conditions which are present at local scale(i.e. within area of limited size).For example-immediate surroundings of various organisms. Macroclimate: Forest is an example of macro-climate. Here, dense foliage retards the quantity of light falling on ground. It also changes the prevailing temperature.         

important types of particle

These particles vary in size and on the basis of soil particles and divided into following categories:

Gravel–more than 2 mm

Coarse sand–2 to 0.2 mm

Fine sand–0.2 to 0.02 mm

Silt–0.02 to 0.002 mm

Clay–less than 0.002 mm

On the basis of relative proportion of these particles, soils are of following types:

Sandy soil: It is formed of 85% sand and 15% clay and silt. It is also called Light soil. It has high porosity percentage of pore-spaces in a given volume of soil) so has loose soil with low water holding capacity. It also has large Temperature fluctuations. It is characterized by the xerophytic plantations. This soil is not rich in nutrients and is less fertile.

Clayey soil: It is formed of 50 % clay and 50 % salt or sand or both. It is also Called cold or heavy soil. It has fine pore spaces so very high water holding Capacity. The temperature does not fluctuate much. It does not allow easy Penetration of soil and has less water logging capacity and presence of CO2.

Salt soil. It has 90% silt and 10 % sand. It has good soil porosity and water holding capacity but is poor in nutrient supply.

Loamy soil. It consists of 70% sand and 30% clay or silt or both. It is best soil For the plant growth because of its good water holding capacity, water Infiltration and adequate aeration. Root penetration is also good in loamy soil. Minerals, also called biogenic nutrients, are essential for the proper growth of Organisms so the type and distribution of plants and animals are determined By specific distribution of minerals. Deficiency or absence or excess of minerals results in abnormal growth or even death of organism.

Snails occur in soils rich in calcium content.

Halophytes and some sea animals have salt secreting glands.

Soil, deficient in copper and cobalt, is unfit for raising cattle. High concentration of minerals greatly limits the distribution of animals e.g. Dead sea and great salt lake (areas with high salt contents) are devoid of much vegetation.

Soil nature and distribution of vegetation:

The type of soil (sandy, loamy or clayey) and its water retention, aeration and Mineral contents determine the nature of plants and animals. On the basis of  These characters of soil, the plants are divided into following ecological categories.

Halophyets: The plants found on saline soil e.g. Rhizophora, Heritiera, etc.

Lithophytes: The plants found on rocky surface.

Chasmophytes. The plants found in rock crevices.

Oxylophytes (Calcifuges).The plants found on acidic soils e.g. maize, barley, Potato, Rumex and Rhododendron.

Calcipphytes. The plants growing on calcium-rich soils.

Soil water: soil water is more important than any other ecological factor in Distribution of  plants because it is required for meeting the metabolic and Transportational needs of soil flora, soil fauna and the process of Humification Soil water is derived from rain. Rain water occurs in following forms:

Run-away water: It is drained away from the soil surface along the slope and is also called runoff. Gravitational water It is that amount of water which percolates downward Under the force of gravity and finally reaches the water table.

Capillary water: The water held up by capillary forces between the soil Particles in the micropores is called capillary water. This is the best form of Water available to the plants.

Soil air: Soil air is present in the pores of the. soil and is necessary for respiration of roots and soil flora and fauna. If the soil is not water-logged It pores partly contain water and partly air. The soil air is slightly rich in CO2 And poorer in O2 due to respiratory activities of underground parts of plants And micro-organisms. The oxygen of soil air is an important factor controlling

Soil fertility because it is required by humus forming micro organisms, nitrogen-fixing bacteria and other soil organisms like earthworms which increase the soil fertility.

important examples of BIOTIC FACTORS

Biotic community is an association of a number of interrelated populations Belonging to different species ,in a common environment which can survive In nature(Clarke, 1967).Biotic community was called biocoenosis(Mobius,1880).Clements(1916) stated the community as a sort Of super organism whose member species were tight bound together both Now and in their common evolutionary concept.

Tolerance range

Some examples are:

Plant growth is reduced in deserts due to less availability of water. In deep lakes, due to low phosphorus contents, growth of phytoplanktons is retarded. Biotic community is an assemblage of a number of different but interacting Populations of different species. These populations can be divided into animal Community, plant community and microbial community. These three types of Communities in a biotic community are interdependent. The gradual physiological adjustment to slowly changing new environmental Conditions is called acclimatization.

Osmoregulation involves regulation of osmotic concentration of the body fluids by regulating the water level in them. In all the vertebrates including Human beings, osmoregulatory organs are kidneys. The kidneys are flexible in Osmoregulation.

Osmoregulators and osmoconformers

Osmoregulators are those animals which can maintain an internal osmolarity different from the surrounding Medium. Most of fresh-water invertebrates and most of vertebrates maintain A narrow osmolarity range and are called strict osmoregulators except Myxine(Hag –fish, a marine cyclostome) and elasmobranchs (sharks and rays)Osmoregulators eliminate excess of water if they are in a hypotonic medium. Osmo-conformers: These are those animals which have wide range of osmolarity of their body fluids and change their osmolarity according to that of surrounding medium.

important characteristics of population

population is defined as the total number of individuals of a Species in a specific geographical area, can interbreed under natural conditions to produce fertile off springs and functions as a unit of biotic Community.


Different populations can be compared by measuring these characteristics

Population size and population density.

Birth or Natality rate.

Death or Mortality rate.


Age distribution.

Population growth.

Biotic or Reproductive potential.

Environmental resistance.

Carrying capacity.

Sex ratio.

Age ratio.

Population fluctuations and population cycles.

Population size and population density. Population size indicates the total Number of organisms of a specific species present in a specific geographical area at a specific time. Population density of a species is the number of individuals of a species per unit area or volume.

  • Birth or Natality rate. It is generally expressed as number of births per 1,000 individuals of a population per year.
  • Death or Mortality rate. It is opposite to natality rate .It is commonly Expressed as the number of deaths per 1,000 individuals of a population per year.