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Cyanobacteria General characters: Also called as Blue-green algae. Found in water and other wet places. These are oxygenic photosynthetic, prokaryotic and gram negative bacteria. The outer layer of cell wall is made of lipo-polysaccharides and inner layer is having peptidoglycon. Ribosomes, thylakoids and phycobilosomes are present in cytoplasm. Ribosomes are 70s type, thylakoids contains phycobilosomes which has photosynthetic pigments like phycocyanin, phycoerythrin and small amount of protein. Reserve food material is cyanophycin granules, starch, glycogen, phosphate granules. Gas filled vacoules helps the bacteria to float on the surface of water.  Vegetative reproduction is by fission, fragmentation and by locomotion harmagonia. Asexual reproduction is byformation of akinites, endospores, exospores and nanocytes. Thallus organisation in cyanobacteria: Thallus organisation in the sense no differntiation of organism into different parts. It is in  three forms.

Lichens: The symbiotic assosiation between fungi and algae resulting in a plant body is called lichens. Plant body of lichen thallus is irregular and made up of algal component i.e. phycobiont and fungal component i,e. Mycobiont. Differnt forms of lichens: 1. Crustose lichen:     These are flat, thin, crust like thallus appeared partly or completely embedded into the substratum.  Ex. Rhizocarpa graphis. 2. Foliase lichens:    These are flat, leaf like lobed thallus attach to the substratum with the help of rhizoids.  Ex. Permeria. 3. Fruticose lichens:     These are brush like hanging cylindrical or spherical shape. Attached to substratum with the help of basal mucilage disk.      Ex. Cladonia. Internal morphology of lichen thallus:    It shows mainly four zones. They are:            1. Upper cortical zone            2. Algal zone            3. Medullary zone            4. Lower cortical zone 1. Upper cortical zone:           It is a protective

Classification by Aristotle: Aristotle was the earliest to attempt a scientific basis for classification. He classified plants and animals as two groups He classify plants into trees, shurbs and herbs. He divided animals in two groups , those who have red blood  and those do not contain red blood. Classification by Linnaeus: Linnaeus classified as Two Kingdoms, i.e Plantae and Animalia. But this two kingdom classification found inadequate because a large number of organism did not fall in either category. There was no differentiation between unicellular and multi cellular, autotrophic and heterotrophic, difference in their cell wall composition, so a need was felt to classify them in an appropriate manner. So Whittaker classified it again and it is widely used now a days. Whittakers classification: R.H.Whittaker proposed a Five kingdom classification in the year 1969. They are Monera Protista Fungi Plantae Animalia The main criteria for classif

Normally secondary growth is absent in monocots. Monocots live for a short period of time and complete its life cycle. Example:jawar, maize, rice etc., But Dracena shows abnormal secondary growth being a monocot stem. Dracena belongs to Lilliaceae family. Formation of Periderm: During secondary growth few peripheral cells of general cortex becomes active and forms Meristem. This acts as Cork cambium or Phellogen. This cork cambium cuts off Cork tissue or Phellem towards outside and secondary cortex or phelloderm towards inside. By this periderm is formed. Formation of cambium: The inner peripheral cells of general cortex becomes meristemetic and forms cambium. Cambium forms parenchyma cells and xylem elements in its inner side. After a short period of time activity changes. Phloem is formed in such a way that phloem is surrounded by xylem. This type of vascular bundles are called Amphiphloic type. In which phloem is surrounded by xylem.

 YEH BAAT SAMAJH MEH AAYI NAHI... Ye baat samajh me ayi nahi Aur ammi ne samjhai nahi Mai kaisay meethi baath karu Jab maine mithaai khai nahi Aapi bhi pakati hai halwa Phir vo bhi kyu halwai nahi Ye baat samajh me ayi nahi Nani k miya toh nana hai Dadi k miya bhi dada hai Jab aapa se maine pucha Baji k miya kya baja hai Vo hans hans kar ye kehne lagi Ay bhai nahi ay bhai nahi Ye baat samajh me ayi nahi Jab naya mahina ata hai Bijli ka bil aa jata hai Halankey badal bechara Ye bijli muft banata hai Phir hum ne apne ghar bijli Badal se kyu lagwai nahi Ye baat samajh me ayi nahi Agar billi sher ki Qala hai Toh hum ne isay kyu pala hai Kya sher bahot naalaiq hai Qala ko maar nikala hai Yaa,jungle k raja k yaha Kya milti doodh malai nahi Ye baat samajh me ayi nahi Kyu lambay baal hai bhaalu k Kyu is ki tind karai nahi Kya vo bhi ganda bacha hai Ya iske abbu ,bhai nahi Ye iska hairstyle hai Yaajungle me koi naai nahi Ye baat samajh me ayi nah

Definition of population: All the living organisms of same species living in a particular locality constitute the population. Population include various types of organisms which belongs to same species. We can found number of populations on planet Earth. Like human population, ant population, cats population, and many more.

Ecosystem: Two or more biotic communities which interact with the physical or non-living environment together constitute as Ecosystem. Examples: A forest, a mountain, a garden, a pond etc,.. Biome: Group of ecosystem constitute as Biome. A group of ecosystem taken togther in an area hving the same type of climtic conditions is consider as Biome. Biomes can also be consider as major or big sized ecosystem.  Examples: Temperate forests, deserts, evergreen forests, sea, big lakes etc,.. where many ecosystems are found within a biome.

Community: Definition: The population of different species found in aparticular place constitute the community. Example: In a garden, we can find different species which are living in a same environment such as insects, rodents, lizards, birds, ants, honey bees and many more species can be seen. Biotic community: Definition: Population of all the different species which are found in the garden constitute a Biotic Community. Biotic refers to the organisms which is different from human communities.

Vacuole: Vacuoles are the clear cavities in the cytoplasm.   These are filled with water and various substances in solution. Animal call contains small and less number of vacuoles. Plant cells contains large vacuole Sap: In plant cells vacuoles are large and contains a liquid called cell sap or sap.

SECONDARY GROWTH IN PLANTS: Increase in width of the plant is considered as secondary growth. Secondary growth is seen in second year of plant growth.  Secondary growth takes place in two steps. They are: 1.Cortical or Extra-stelar growth. 2. Stelar growth CORTICAL OR EXTRA-STELAR GROWTH: Formation of periderm: The cortex of the stem gets modified to meristem and acts as Cork cambium or Phellogen then it continuously divides towards outer side to form Cork tissue or Phellem and divides inner side to form Secondary cortex or Phelloderm The Phellogen, Phellem and Phelloderm together called as Periderm. Thus plants increase in its width. STELAR GROWTH: Formation of Intrafascicular cambium: The cambium which is present between xylem and phloem gets activated(able to divide) and forms Intrafascicular cambium. Formation of Interfascicular cambium: Medullary rays which is present between vascular bundles develops a cambium, that cambium is called I

BANANA CONTAINS POTASSIUM WHICH IS USEFUL FOR US. DON'T EAT BANANAS ON AN EMPTY STOMACH;COMBINING THEM WITH A BIT OF PROTEIN WILL HELP TO NORMALIZE THE INSULIN RESPONSE CAUSED BY THE SUGAR IN BANANA. CHICORY IS BENEFICIAL  FOR DIGESTION, THE CIRCULATORY SYSTEM AND THE BLOOD. BEET ROOTS ARE HIGH IN CARBOHYDRATES LEVEL. PEANUTS CONTAINS BENEFICIAL PROTEINS, BUT MANY PEOPLE ARE ALLERGIC TO THEM AND FIND HARD TO DIGEST. ONIONS ARE EXCELLENT ANTI-OXIDANTS, AND THEY CONTAIN ANTI-ALLERGY, ANTI-VIRAL AND ANTI-HISTAMINE PROPERTIES. SWEET POTATOES ARE AN EXCELLENT SOURCES OF CAROTENOID ANTIOXIDANTS. TOMATOES ARE AN EXCELLENT SOURCE OF VITAMIN C. TOMATOES ARE RICH IN CAROTENOID AND LYCOPENE; EATING FOOD CONTAINING CAROTENOIDS CAN LOWER THE RISK OF CANCER. CAKES AND COOKIES CONTAINS TOO MUCH SUGAR AND NOT ENOUGH VITAMINS AND MINERALS. ORANGES ARE MORE FIBROUS THAN THE FRUITS AND VEGETABLES. SO TAKE ORANGES

In winter, the air in our Atmosphere is very cool as compared to the air coming out from our mouth. The vapours which is present in the air is very cool. when we talk the air which comes out from our mouth is hot then that air mixes with surrounding cool air. s the cool air and hot air from our mouth mixes and forms a tiny droplets  These tiny droplets concentrated in a limited area, appear like smoke or a small cloud near your mouth.

WHAT IS DEFORESTATION? Deforestation is cutting down of forests or trees for many purposes like building offices, schools, restaurants, hotels and many more things. we generally cut down trees for our needs. but cutting these trees really giving any benefit to mankind and its environment? How worse it is affecting on our environment? LIVES WHICH ARE DEPENDENT ON PLANTS.... Every thing in our environment is dependent on each other directly or indirectly. Like wise many lives are dependent on trees. Cutting trees are getting affected to not only humans and atmosphere but also it effects on Animals too. Tree as a Habitat for Animals: Birds, Monkeys, squirrels, snakes, ants, spiders, caterpillars, moths, bees, wasps, small plants(mosses), mosquitoes, are some of the organisms that you may find on a tree. Tree is a place where different types of animals live. Some very small plants also grow on the barks of trees. Trees are habitats for most of the Animals.

Anti-oxidants: Antioxidants-definition Substances that can prevent oxidation, which means it prevents the damage to the cell. It causes damage by forming free radicals which leads to chain reaction to environmental and other pressures. What do Antioxidants do in our body: Antioxidants boost overall health of the body. It neutralises the free radicals and can reduce Oxidative stress. It prevents from many diseases. It prevents heart disease, cancer, arthritis, stroke, respiratory diseases and other inflammatory or ischemic conditions. Sources of Antioxidants: Mostly we can find Antioxidants in plant based foods like fruits and vegetables.  In almost all food items which we eat contains Antioxidants. Dairy products. Eggs Meat Liver Nuts and seeds Fruits and vegetables Berries Bright colored vegetables and fruits Spinach Egg plant           And more such food items contains Antioxidants. 

PROTOXYLEM:  The first formed primary xylem is called protoxylem METAXYLEM: The later formed primary xylem is considered as metaxylem. EXARCH: If protoxylem lies towards centre that is towards pith and metaxylem lies towards periphery then type of primary xylem is called exarch. ENDARCH: If protoxylem is towards periphery and metaxylem is towards centre(pith) then such arrangement of primary xylem is called as endarch.

PROTOPHLOEM: The phloem containing narrow sieve tubes. such first formed primary phloem is considered as protophloem. METAPHLOEM: Phloem containing larger sieve tubes. such later formed phloem is called metaphloem.

ARRANGEMENTS IN VASCULAR BUNDLES RADIAL: When xylem and phloem in a vascular bundles are arranged in alternate manner on different radii then such arrangement is called Radial arrangement. CONJOINT: Xylem and Phloem when arranged on same radii in the vascular bundles is considered as Conjoint. OPEN: When xylem and phloem are seperated by vascular cambium. Such arrangement with cambium is considerd as Open vascular bundles as in Dicots. CLOSED:  Vascular cambium is absent in between the xylem and phloem such arrangement of vascular bundles with no cambium is called Closed vascular bundles as in Monocots.

 TWO MAIN DIFFERENCES BETWEEN C3 AND C4 PLANTS: There are two main differences which exhibits in C3 and C4 plants internally. They are: 1. Kranz anatomy in C4 plants and absent in C3 plants. 2. Photorespiration in C3 plants and absent in C4 plants. Now this explanation will help you to understand the differences. In C4 plants, internal strucutre of leaf has bundle sheath cells around the vascular bundlles. Such anatomy of leaves are considered as Kranz anatomy . The cells contain chloroplast and it is impervious to gases exchange and no intercellular spaces in it. In C3 plants photorespiration process takes place. It is stated that photorespiration is a wasteful process because it does not yield ATP and NADPH but rather it utilises ATP to release CO2. In C4 plants it lacks because they have a mechanism that increase CO2 concentration and has a capacity to minimise the oxygenase activity. so in  C4 plants productivity and yield is better than C3 pla

PIGMENTS: Pigments are the substances that have an ability to absorb the light at different wavelengths. There are four types of pigments in plant. They are: 1.Chlorophyll a- (bright or blue-green) 2.Chlorophyll b-(yellow green) 3.Xanthophylls-(yellow) 4.Carotenoids-(yellow to yellow-orange)  * Chlorophyll a is the most abundant pigment responsible for trapping light. Other pigments are accessory pigments which protect chlorophyll a from photo-oxidation .

   In plants, growth starts from the germination of seeds. Then it develops internally and externally forming various parts. Plants undergoes primary and secondary growth which differs from each other in many ways. Primary growth in plants exhibits in plants within 1 year then plant undergoes secondary growth. PRIMARY GROWTH IN PLANTS: Primary growth in plants takes place inside the stem. Both dicotyledenous and monocotyledenous plants undergoes primary growth, and of course they show some variations. IN DICOTYLEDENOUS PLANTS: Stem consist of three zones . They are: 1.EPIDERMIS 2.GROUND TISSUE 3. STELE 1.EPIDERMIS: It is the outermost layer covered by cuticle. Epidermis protects the inner parts of the stem. Cuticle covers the epidermis and helps in transpiration. It may have trichomes and stomata. 2. GROUND TISSUE: The tissues other than vascular bundles and epidermis is considered as ground tissue. It is again divided into three

STOMATA: Stomata are the structures which is present on the epidermis of leaf mainly but in some plants it is also present in stems. *In Monocots stomata is dum-bell in shape *Whereas in Dicots it is bean shaped. Stomata consist of two types of cells. They are: 1. Guard cells 2. Subsidiary cells. 1. Guard cells: In Dicots the guard cells are bean shaped whereas in monocots guard cells are dum-bell shape. There are two guard cells in each stomata. As the stomata is bean shaped, the curved walls of stomata are thin and it has elasticity which means it has microfibrils through which water gets absorbed by the cell. A stomatal pore is present between the two guard cells. Inside the guard cells cytoplasm, organelles and chloroplast is present. Chloroplast helps in photosynthesis. When the cell absorbs the sunlight, chloroplast gets activated and forms sugars inside the cell. as a result the concentration inside the cells gets

TRANSLOCATION OF MINERAL IONS: Different ions when reached to the xylem through active or passive transport, then further transport takes place through transpiration. The mineral elements sink at the growing regions of the plant such as the apical and lateral meristems, young leaves, developing flowers, fruits, seeds, and the storage organ. When the old parts gets dies or leaves fall off before dying the minerals get remobilised to the younger parts of the plant. Older leaves exports the minerals to the younger leaves. the elements which gets mobilised are Phosphorous, Sulphur, Nitrogen and Potassium. But the Calcium will not get mobilised. Much of the elements are carried in the form as Amino acids and related compounds. Phosphorous and Sulphur carried as organic compounds and Nitrogen is carried out as Inorganic compound. Hence, it is not that xylem transports only inorganic substances and phloem carries organic substances as it is traditionally believed. They both c

Transpiration pull: In higher plants water is transported through xylem. This movement is accomplished by 'pulling' of water to the leaves of the plant. This is referred to as cohesion-tension-transpiration pull model  of water transport. This takes place in the higher plants . Transpiration  Less than 1 percent of water is utilized in the process of photosynthesis. Water is lost from the plants through stomata in the form of vapour on the surface of leaves. This process of removing water through stomata of leaves in the form of vapour is called as Transpiration.

DORSIVENTRAL LEAF: The dorsiventral leaves are found in dicots. In the vertical section of dicot leaf there are mainly divided into three parts. They are. Epidermis Mesophyll Vascular Bundles Epidermis: The upper and lower epidermis of leaf is covered by cuticle. The Adaxial(lower) surface has more number of Stomata than upper surface.Sometimes the upper surface lacks Stomata. Mesophyll: The layer present between the upper and lower epidermis is called as mesophyll. It possess chloroplast and carry out photosynthesis. it contains parenchymatous cells. Mesophyll is two types of parenchymatous cells.     -Palisade parenchyma     -Spongy parechyma Polisade parenchyma is an elongated cell,arranged vertically and parallel to each other. present on upper side of mesophyll Spongy parenchyma are oval or round loosely arranged situated below the palisade parenchyma extending to the lower epidermis. it contains air cavities.

ISOBILATERAL LEAF (MONOCOTYLEDENOUS): General features: Isobilateral leaves are found in Monocot leaves. Stomata is equally distributed on lower(abaxial) and upper(adaxial) surface of the leaf. Cuticle covers both upper and lower surface of the leaf. Leaf  is distinguished into three parts. Theyare              -Epidermis              -Mesophyll              -Vascular bundles Epidermis has stomata and cuticle.  In monocots Mesophyll is not defferentiated into polisade and spongy parenchyma unlike in Dicots.  Vascular bundles are seen in the mid-ribs and veins of the leaf. The size of the vascular bundle is depend on the size of the veins. Parellel venation is present in monocot leaves. In grasses ,certain upper epidermal cells along the veins modify themselves into large empty colourless cells.these are called Bulliform cells. When bulliform cells absorbs water it becomes turgid and the leaf surface gets exposed. When they get

Guttation: It is the removal of excess of water in the form of water droplets is called guttation. This can be seen only in shurbs and herbs. And not in higher plants. Water droplets are found when the evaporation is low, during early morning and evening, droplets can be seen on the tip of veins and surface of leaves. Guttation is found only in Root pressure type of transportation of plants.                              Transpiration: It is the process of removal of water from the upper surface of leaves through stomatal opening in the form of water vapour is called Transporation. This is seen in higher plants and takes place when the excess of water is present. It creates tranpiration pull for absorption and transport of plants. It supplies water for photosynthesis. Also transports minerals to the various parts of the plant. It keeps the cell turgid and cools leaves surface by evaporative cooling.                                

Root pressure: Water and minerals are transported from roots to the different parts of the plants by a passive process in a small height plants like herbs and shurbs. This process of transportation is called Root pressure This is a process of 'pushing' up of water to small heights. Guttation: Water loss from the plants in a liquid phase is known as guttation. This takes place in shrubs and herbs. It takes place only in root pressure type of transportation.

Constipation: The bowel movement does not take properly and is hard to pass outside of the body. The feacus get dry and hard to pass. This happens because of dehydration, improper eating, lack of dietary fibres. This causes abdominal pain. This can removed by taking food which contains fibre. This allows easy bowel movements and this problem can be removed.

Transcription: It is the process in which the double standard DNA is transcripts into single standard mRNA. This process involves in protein synthesis.            DNA→mRNA mRNA is the small piece of DNA . This single standard mRNA forms the second strand in the opposite direction. In this mRNA Adenine binds with Uracil instead of Thymine.       In DNA                 In mRNA            A⇉T                         A⇉U      G⇛C                        G⇛C This takes place in nucleus and then reaches to cytoplasm. Translation: This takes place in cytoplasm. In this process proteins are formed by mRNA.            mRNA→Proteins mRNA binds with Ribosomes and forms the proteins. By this amino acids are formed which together called as proteins.                         

Immune system is responsible for affecting with the foreign bodies or germs and getting affected by the diseases. In childrens the immune system is lower in size and not powerful so as we grow up and reaches at the adult stage, simultaneously the immune system also grows in a large size and at adult stage  the immune system will be at its peak level preventing from all type of diseases. Then as we grew much older the immunity also decreases, when we become old, again it reduces to its  initial size as it was in the children stage that is reduced size of immune system. This is the reason that children and old peoples get affected early by the diseases as it has much reduced size immunity. Whereas in adults the immune system is at the peak level and at that stage they will not get affected easily by diseases and they are more energetic at that stage and possesing a capability of doing a much work.

Sometimes, you feel fullness in your upper abdomen or in your stomach. This happens because of over eating, eating of spicy, fatty, oily,  and heavy foods. This fullness is also due to filling up of gas because of eating heavy food items. The food did not get digest so it leads to feeling of fullness. Spicy and oily foods are mainly responsible for this. The scientific term used for this is 'Indigestion'. This does not cause any disorder in the body but it feels uncomfortable for a time and then it gets normal after taking a curd or anything which is helpful in digesting the food. Curd is the simple and easy remedy for getting rid of this problem and which feels you comfortable after having a glass of curd.

Antigens:  These are the substances which enters into the body and attacks on the immune system and causes harm to the body.  These are the foriegn substances that induce the production of antibodies. However antigens are responsible for the formation of antibodies. Antibodies are produced by the immune system. Antibodies: These are the proteins which are formed by the immune system and kills the harmful foreign substances. Antibodies get activated when any foreign substance enters into the body.  Antigens induce to produce antibodies and both antigens and antibodies fights with each other and either of them gets win. It means if antibodies succed in killing antigens then it causes no harm to the body. And if antigens kills the whole antibodies then it may cause harm to the body. Production of antibodies is depend on the efficiency of our immune system. If the immune system is powerful then more amount of antibodies are produced. Immune system is at the peak level i

         Functional groups          Formulae         1.       Alcohol                                R-OH         2.       Ketone                                 R-CO-R              3.      Aldehyde                              R-CO-H         4.      Carboxylic acid                   R-COOH         5.       Ether                                    R-O-R         6.       Ester                                     R-COO-R         7.       Amides                                 R-CO-NH₂         8.      Cyanides                               CN⁻           9.      Nitriles                                  R-CN        10.     Carboxylate ion                  R-COO⁻        11.     Thiols                                    R-SH        12.     Azide                                       N⁻³         13.     Amines                                  R-NH₂         14.     Imine                                    R₃N⁻         15.     Imide   

Plants are generally planted for the reduction of  air pollution and to provide a refreshing breath to us. But how did it happen? Actually many of us have a wrong perception that plants releases oxygen and intakes carbondioxide But in the Respiration, the process which involves uptake of oxygen and release of carbondioxide, there is no oxygen which is released in the environment and instead of that carbondioxide is releasing. So how it is helpful to us and to the environment? During the process of photosynthesis, plants utilises carbondioxide, water,sunlight as the major components and prepare its own food material. Photosynthesis takes place only during day time.  Thus plants utilises carbondioxide for photosynthesis which helps in reduction of that harmful gas from the atmosphere. But during the night time photosynthesis process is not possible as there is no light. So plants undergoes only Respiration process at night. It might be harmful to our health to be near the

Yes. Male Pigeon produces milk.     In pigeon both the sexes, male and female produces milk and feed thier young one's.     Milk is produced in Crop region. Mainly in the glandular region of crop, the milk is produced to feed the young ones.      The Prolactin harmone stimulates and controls the formation of pigeon's milk.

External features to identify Monocts: By leaves : Monocots consist of parallel venation. This is the main feature for identifying monocots. By Roots : Fibrous roots are present in monocots. By Seed : Embryo contains single cotyledon. Ex: Wheat,maize,etc. External features for identifying dicots: By leaves  : Reticulate venation on the surface of leaves. By Roots  : Tap root system is found in dicots. By seed  : Embryo  contains two cotyledons. Ex: Gram, pea, etc.

Tissues: A group of cells which are structurally and functionlly similar are called as tissue. Types of tissues: Tissues are of two types 1.Meristematic tissue. 2.Permenant tissue. Meristematic tissue: A group of cells which are immature and involves in active cell division. These are present at the apical region of root, stem and lateral branches.    Meristematic tissue is again divided into many types based on origin, position and plane.     On the basis of origin it is divided into two types. They are:         a. Primary meristem.         b. Secondary meristem.      On the basis of position it is further divided into three types. They are:         a. Apical meristem.         b. Intercalary meristem.         c. Lateral meristem.       On the basis of plane of division it is divided into three types. They are:         a. Plate meristem.         b. Rib meristem.         c. Mass meristem. Permenant tissue: A group of cells which are matur

MEIOSIS: The cells undergoes division and results in the formation of haploid daughter cells and reduces the number of chromosomal number by half. Meiosis is also called as Reduction division or Heterotypic division. Key  features of meiosis: It involves nuclear and cell division called meiosis-1 and meiosis-2 respectively. Only one cycle of DNA replication takes place. It involves paoring of homologous chromosomes and recombination between them. At last four haploid cells are formed . Meiosis-1: Meiosis-1 initiates when the parental chromosomes replicate to produce identical sister chromatids.     It has four phases. They are: 1.prophase-1 2.metaphase-1 3.anaphase-1 4.telophase-1 Prophase-1: It is sub divided into five(5) phases. 1. Leptotene : chromosomes comes closer together and visible under microscope. 2. Zygotene:  chromosomes start pairing together forming a synapse. Paired chromosomes are called homologous chromosomes. This c

Stereoisomers are further divided into two types. They are 1) Enantiomers 2)Diastereomers Enantiomers: These are the isomers which are mirror images and non-superimposable are called  Enantiomers. These are also called as optical isomers. Ex.(+)Menthol and (-)Menthol. Diastereomers: These isomers are non-mirror images and non-superimposable are called Diastereomers.    

Constitutional isomers are further divided into three types.They are: 1)Positional isomers 2)Functional group isomers 3)Chain isomers Positional isomers: The compounds having the same molecular formula but differ in the position of double bond or triple bond or the functiobla group are called positional isomers. Ex:  But-1-ene ; But-2-ene.       Pentan-1-ol ; Pentan-2-ol. Functional group isomers: The compounds having the same molecular formula but which differ in the functional groups is called functional group isomers. Ex:C₂H₆O⇒CH₃-CH₂-OH(Ethanol)  ;  CH₃-O-CH₃(Dimethyl ether). Chain isomers: The compounds having same molecular formula but differ only in arrangements of carbon atom in the main carbon chain. Ex: C₄H₁₀⇒Butane ; 2-Methyl propane.

ISOMERISM: The compounds having the the same molecular formula but which differ in their properties is called as Isomers and the phenomenon is considered as Isomerism.          It is further categorized into two types: They are 1) Constitutional isomerism. 2) Stereoisomerism. 1) Constitutional isomerism: The compounds constituting same molecular formula but differ in the arrangement of atoms or ions within a molecule is called as Constitutional isomers and the phenomenon is called Constitutional isomerism. 2)Stereoisomerism: The compounds having the same molecular formula vut which differ in spatial arrangement of atoms or groups around the carbon atom is called stereoisomers.

Electrons: Negatively charged ions are considered as electrons. Electrons are discovered by J.J.Thomson. Protons: Positively charged ions are considered as protons. It was discovered by Ernest Rutherford. Neutrons: The ions which contains No charge  are called Neutrons. It was discovered by James Chadwick.

Placenta: The organ which is formed by the combination of foetal tissue and maternal tissue for the exchange of nutrients and gases are called as placenta.     The foetal tissue is the part of foetus and maternal tissue is from uterine wall of mother. Placentation: The intimate relation between uterine wall of mother and foetal tissue which is  mainly from chorionic membrane of foetus for the exchange of nutrients, minerals, respiration and excretion is called Placentation.

Neoteny: The occurance of both adult and juveline characters together in an organism is called as Neoteny.    This is seen in Amphibians. Example is Axolotol larva of Ambylostoma.   Neoteny can also be defined as the loss of sexual maturity in the organisms and retain of larval characters along with adult characters. Why Neoteny is observed in an organisms? Neoteny occurs due to lack of thyroid stimulating harmone which stimulates thyroid to produce thyroxine. The hypothalamus of the brain fails to stimulate the thyroid gland to produce growth harmone which stops the metamorphosis. Axolotol of Ambylostoma can again get metamorphose by giving injections of Iodine or by giving shocks of Thyroxine harmone.

Prokaryotes: Prokaryotes includes bacteria, blue-green algae, mycoplasmas and PPLO. They are smaller and multiply more rapidly. They vary greatly in shape and size. All prokaryotes have a cell wall and cell membrane. No well defined nucleus. Matrix is filled with cytoplasm. In addition to genomic DNA, it has smaller DNA's called Plasmids which is resistant to antibiotics. No organelles are present except ribosomes. It has unique Inclusions. Inclusions is the reserve material stored in the cytoplasm. Differentiated form of cell membranes called mesosomes is the characteristic of prokaryotes. Eukaryotes:  Eukaryotes includes protists, plants, animals and fungi. Compare to prokaryotes, they multiply slowly. The cells are not identical. All eukaryotes do not have cell walls. Well defined nucleus with a nuclear envelope. Cytoplasm have many compartments due to presence of cell organelles. Genetic material is organised into chromosome. Many membrane bound cell

Syrinx Syrinx is a 'vocal organ' which is found only in birds.  It produces sound in birds. It is situated between trachea and bronchi of a bird. Supported by last few(three) tracheal rings and first two brnnchial rings.      Syrinx consist of expanded chamber called "Tympanum" which is also supported by last three or four tracheal rings and first two rings of bronchi.        The voice is produced by the vibration of tympaniform membrane when the air expelled out from the lungs. Mucous membrane of each bronchus forms an internal tynpaniform membrane and External tympaniform membrane. These membranes are regulated by "Intrinsic syringial muscles" and apair of "Sterno-tracheal muscles".   At the junction of two bronchi a bony ridge,the "Persulus" extends dorso-ventrally.

Fruit is a characteristic feature of flowering plant. A friut is a ripened or mature ovary which is developed after fertilisation.    If a fruit is developed before fertilisation then such fruits are considered as Parthenocarpic fruits.     Banana is one such example of parthenocarpic fruit.   Generally ovary develops into fruit and ovules develop into seeds. But in banana seeds are absent and fruit is developed before ovary gets fertilised.