12th class Biology notes for sure success

1. Antibody
• These are glycoproteins secreted by the plasma cells.
• These are Y-shaped and composed by two heavy chain and two light chain.
• Both chain are held together by disulphide bridge.
• Antibodies are of five types- IgG,IgA,IgM,IgE and IgD.
• Antibodies destroy the antigen by – opsonization, precipitation, agglutination.
2 Interferon
• Interferon are glycoproteins secreted by virus infected cells to protect neibouring cells.
3 Genetic code
• The sequence of nitrogenous bases on mRNA in the form of codon is called genetic code.
4 Law of independent assortment
This law state that in the inheritance of two pairs of contrasting characters, the factors of each pair of characters segregate independently of the other factors of the other pair of characters.

5 Co-dominance
• The phenomenon in which two alleles of a gene are equally dominant and express themselves in the presence of the other is called co-dominance.
6 Incomplete dominance
• The phenomenon in which neither of the two alleles of a gene is completely dominant over the other is called incomplete dominance.
7 Aneuploidy
• The phenomenon of gain or loss of one or more chromosomes that results due to failure of separation of the homologous pairs of chromosomes during meiosis is called aneuploidy.
8 Linkage
• The phenomenon in which two or more linked genes are always inherited together is called linkage.
9 Translation
• The biological process of polymerization of amino acids to form a  polypeptide dictated by mRNA on ribosome with the help of tRNA is called translation.
10 Transcription
• The process of copying of genetic information from antisenestrand of the DNA into hnRNA is called transcription.
11 Replication fork
• The Y shaped structure formed when double stranded DNA is unwound during its replication is called replication fork.
12 PCR
• The process of making multiple copies of the DNA segment in vitro is called PCR.
13 Cryopreservation
• The storage of materials at ultra low temperature either by very rapid cooling or by gradual cooling is called cryopreservation.
14 Southern blotting
• The process in which separated DNA sequences are transferred onto a nitrocellulose or nylon membrane/sheet placed over the gel is called Southern blotting.
15 Main principle of biotechnology
• The technique of altering the nature of genetic material and/or introduction of it into another host organism to change its phenotype.
• Technique to facilitate the growth and multiplication of only the desired microbes/cell in large number under sterile condition for the manufacture of biotechnological products.
16 Tropic level
• Every step in a food chain is called tropic level.
17 Nucleotide
• Nucleotide= phosphoric acid + nitrogen bases + pentose sugar
18 Nucleoside
• Nucleoside =Nitrogen bases + Pentose sugar
19 Analogous organ
• Those organs in different groups of organism which are similar in their function but different in their origin and structure is called analogous organ.
20 Homologous organ
• Those organs in different groups of organism which have similar basic structural plan but different in their function is called homologous organ.
21 Connecting link
• Those organism which represents thecharacteristics of both two phyllum is called connecting link. e.g. Archaeopteryx.
22 Darwinism
• The theory given by Darwin regarding the evolution of species based on natural selection, survival of fittest and branching of descent is called Darwinism.
23 Hot spots
• Hot spots are the priority area of conservation that are extremely rich in species which have high endemism and are under constant threat of extinction.
24 Genetic diversity
• The diversity of genes within a species is called genetic diversity.
25 Migration
• The phenomenon in which an organism can move away temporarily from the stressful condition in the habitat to another habitat with hospitable condition is called migration.
26 Vestigeal organ
• Those organs which were functional in past but now has been functionless is called vestigial organ.
27 Immunization
• The ability of body to protect itself against antigen developed due to vaccination is called immunization.
28 Standing crop
• The amount of biomass present at every tropic level is known as standing crop.
29 NPP(Net primary productivity)
• It is the amount of energy left in the producers after utilisation of some energy for respiration .i.e. GPP-R=NPPv
30 Ti plasmid
• These are tumor inducing plasmid of Agrobacterium tumefaciens that transforms the normal plants cell into tumour cells.
31 Germplasm
• The sum total of all the alleles of the genes present in an individual organism and its related species is germplasm.
32 Organic evolution
• The process by which change in the genetic composition of population of organism occurs in response to environmental change is called organic evolution.
33 Parthenium weeds
• It is a species of flowering plant inof family astray and are native of Americantropic.it is also called carrot grass. It is a hazardous weeds.
34 Spermiation
• De-attachment of spermatids from Sertoli cells is called spermiation.
35 Down syndrome
• It is a genetic disorders in which suffered individuals have trisomy of 21th chromosome. Suffered individuals are mentally retarded and have congenial heart disease.
36 Sickle cell anemia
• It is a recessive genetic disorders that is caused due to point mutation in 11th chromosome.
• RBC becomes sickle shaped due to formation of valine amino acid in place of glutamic acid of beta globin chain of haemoglobin.
37 Gene therapy
• The technique of replacement or alteration of a defective gene responsible for a hereditary disease is called gene therapy.
38 Multiple allelism
• When a single character is controlled by more than one alleles this phenomenon is called     multipleallelism.e.g human blood group ABO determining allele .
39 Recapitulation theory
• Ontogeny repeats phylogeny i.e. ancestral history repeated during embryonic development.
40 Mutation
• The sudden heritable change in the base sequence of DNA or structure of chromosome or change in the number of chromosomes is called mutation.
41 ELISA
• Enzyme LinkedImmuno sorbent Assay (ELISA) is diagnostic techniques to identify AIDS and Cancer.
42 Crossing over
• Exchange of segments of homologous chromosomes between non-sister chromatids in zygotene sub stage of meiosis I by forming synaptonemal complex is called crossing over.
43 Green house effect
• A natural occurringphenomenon,in which the short wave radiation are absorbed and the long wave radiation are reflected by the earth due to presence of green house gases like methane, carbon dioxide,CFCs and N2O in atmosphere is called green house effect.
44 Ozone hole
• The decline in the thickness of ozone layer in spring is called ozone hole.
45 Global warming
• The increase in the global mean temperature is known as global warming.
46 Algal blooms
• Excessive growth of algae in nutrient rich water bodies is called algal blooms.
47 Biofertilizer
• A substance which contains living micro-organism which, when applied to seeds, plants surface or soil promotes growth by increasing the supply or availability of primary nutrient to the host plant is called biofertilizer.
48 Anticodon
• A sequence of three nitrogen bases on tRNA which is complementary to the codon on mRNA is called anticodon.
49 Plasmid
• These are extra chromosomal ,self replicating,naked circular DNA Found in certain bacteria and in some yeast.
• Plasmid are used in rDNA technology as a vector for foreign DNA.
• The most widely used plasmid is pBR322.
50 Transposons/jumping gene
• A DNA sequence that can change its position within its genome is known as transposons.
51 BT Cotton
• it is pest resistant genetically modified plant in which cry gene are introduced by genetic engineering.
• cry gene are present in Bacillus thurengenesis bacteria that produces cry protein.
• cry protein becomes active at alkaline pH in the gut bollworm and bore its gut.
52 Golden rice
• Golden rice is a vitamin A enriched genetically modified variety of rice.
53 Micropropagation
• The method of producing thousands of plants through tissue culture is called micropropagation.
54 Biological oxygen demand[BOD]
• It is a measure of the oxygen needed by the aerobic decomposers in the polluted water/sewage is called BOD.
• It also indicates the amount of organic matter present in the water.
55 Antibiotic
• Those chemical substances produced by certain microbes that can kill or check the growth of other microbes are called antibiotics.
56 Biopiracy
• The use of bioresourcesby multinational companies and other organisations without proper authorization from the countries and people concerned is called biopiracy.
57 Gene cloning
• The technique of obtaining identical copies of a particular DNA segment or a gene is called gene therapy.
58 Restrictions enzyme
• It is a kind of nuclease enzyme that cuts the DNA molecule at a palindromic site.
59 Transgenic animal
• The genetically modified organism that contains a foreign gene and expresses it, is called transgenic animals.
60 Food chain
• The transfer of energy in the form of food from the producer through a series of a organism is called food chain.
61 Food web
• An interconnected matrix of food chains is called a food web.
62 Apomixis
It is a form of reproduction in which seeds are formed without fusion of gametes.
63 Operon
• A group of genes which controls a metabolic pathways is called operon.
64 Ecology
• The branch of biology that studies the reciprocal relationship between organism and their physical and biological environment is called ecology.
65 Ecosystem
• It is a functional unit of nature consisting of biotic and abiotic factors where the living organisms interact among themselves and also with their physical environment .
66 Adaptation
• Any morphological , physiological or behavioural changes of an organism that enables it to survive and reproduce in its habitat is called adaptation.
67 Homeostasis
• The maintenance of a steady internal environment by organism is called homeostasis.
68 Ecological succession
• It is a community controlled phenomenon in which the structure and composition of communities change in orderly and sequential manner leading ultimately to the establishment of a climax community is called ecological succession.
69 Trisomy
• The condition in which a particular chromosome is present in three copies in a diploid cell is called trisomy.
70 Monosomy
• The condition in which a particular chromosome is present in a single copy in a diploid cell is called monosomy.
71 Allergy
• The hypersensitive response of the immune system to certain antigens in the environment is called allergy.
72 Auto-immune disease
• The disorder in which the body's immune system goes off the track and starts destroying 'self' cells and molecules is called auto immune disease.
73 Active immunity
• When the antibodies are developed by our own body cells in response to the antigen,is called active immunity.e.g. immunity developed by vaccination.
74 Passive immunity
• When the readymade antibodies are injected into the body to destroy antigen,it is called passive immunity.e.g. immunity given to the infant by antibodies in colostrum.
75 Syndrome
• A group of symptoms is called syndrome.
76 Cancer
• The uncontrolled proliferation of cells that results from the break down of regulatory which govern the normal cell behaviour.
77 Metastasis
• The phenomenon in which cancer cellsspread to different sites of body through the body fluids is called metastasis.
78 Founder effect
• The original drifted population change in the phenotype and genotype of the progeny is called founder effect.
79 Genetic engineering
• The technique used to alter the chemistry of genetic material DNA or RNA and introduction of it into change its phenotype is called genetic engineering.
80 Adventage of genetic modified plant
• It can tolerate abiotic stress like cold, heat, droughtetc
• Post harvest loss are much reduced.
• It has enhancednutritional value.
81 Genetic drift
• Random change in the allele frequencies of a population occurring only by chance is called genetic drift.
82 In-situ conservation
• The process of protecting the endangered species of plants or animals in the natural habitat is called in situ conservation.
• It helps in recovering population in the surrounding where they have developed their distinctive features. e.g. national park, biosphere reserve etc.
83 Ex-situ conservation
• The process of protecting the endangered species of plants and animals by removing it unsafe habitat and placing under the care of human is called ex situconservation.e.g. botanical gardens,zoo etc.
84 Sacred grove/forest
• These are the forest patches protected by tribal communities due to religious sanctity  is called sacred grove.
85 Exon
• The coding region of a gene which becomes a part of mRNA and synthesised protein is called Exon.
86 Intron
• The non coding region of a gene which are removed during the processing of mRNA is called intron.
87 Single cell protein
• Use of microorganisms as a alternative sources of protein is called single cell protein.e.g.Spirullina, mushroom etc.
88 Breed
• A group of animals of the same species related by descent and are similar in most of their characters is called breed.
89 Inbreeding depression
• The loss in vigour and fertility due to continueous inbreeding is called inbreeding depression.
90 Totipotency
• The ability of a cell to generate whole plant or animal body is calledtotipotency.
91 Pleiotropy
• The phenomenon in which a single gene product may produce more than one phenotypic effect.
92 Somatic hybridisation
• The process of fusing protoplasts of somatic cells derived from two different varieties or species of plants on suitable nutrient culture medium is called somatic hybridisation.
93 Tissue culture
• Regeneration of whole plant from any cells or tissue of a plant on a suitable synthetic suitable mediumin vitro is called tissue culture.
94 Adventage of tissue culture
• A no.ofplants can be grown in a short period of time.
• Healthy plants are produced from virus infected plants.
• Where sexual hybridisation is not possible ,by tissue culture hybrid plants can be produced.
95 Clone
• A group of morphological and genetically similar organism is called clone.
96 Polyembryony
• The presence of more than one embryo in a seed is called polyembryony.
97 Electronic waste
• Irreparable computers and other electronic goods are called electronic waste.

98. Pollution :- Undesirable change in physical, chemical and biological properties of air, water and soil that adversely affect the organisms is called pollution.

99. Health :-   A state of complete physical, mental and social well-being is called health.

100. Neoplasm

A neoplasm is an abnormal growth of cells, also known as a tumor. Neoplastic diseases are conditions that cause tumor growth. Growth can be either benign (noncancerous) or malignant (cancerous).

102.congenital disease

Congenital diseases are those diseases which are present in the child from birth. Common examples include Cystic fibrosis, Down syndrome, Haemophilia, etc.

103.Role of lymphocytes in immunity

. Lymphocytes play a major role in adaptive immunity.

. B lymphocytes provides humoral immunity by synthesizing  antibodies whereas T lymphocytes providing cell mediated immunity by phagocytosis.

.NK cells destroy tumour cells.

104. DNA polymorphism

- The presence of two or more variant forms of a specific DNA sequence that can occur among different individuals or populations. In other words;  If an inheritable mutation appears in a population at high frequency, this is known as DNA polymorphism. Since inheritable mutations finally lead to evolution, hence study of DNA polymorphism is important from the evolutionary perspective.

-The most common type of polymorphism involves variation at a single nucleotide (also called a single-nucleotide polymorphism, or SNP).

105. Bioprospecting

- Bioprospecting is defined as a systematic and organized search for useful products derived from bioresources including plants, microorganisms, 

animals, etc., that can be developed further for commercialization and overall benefits of the society.

In a simple term - the investigation of living beings to see how they can be commercially useful to human.

106. Red Data Book

- The Red Data Book is a public document that records all rare and endangered species of plants, animals, and fungi existing within the boundary of the state or territory. 

- In simple terms, it is a catalogue of species facing the risk of extinction.

- The International Union and Conservation of Nature and Natural Resources (IUCN) maintains the Red Data Book.

107. Bhopal gas Tragedy

- Bhopal gas tragedy was a chemical accident on the night of 2–3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh, India. 

- The industrial disaster is considered the world's worst in history. Over 500,000 people were exposed to methyl isocyanate (MIC) gas that are highly toxic.

107. Biofortification 

Enrichment of nutritional quality of food crops by scientific methods to improve public health is called Biofortification.

Example:- 1. Golden rice( Vitamin A enriched variety of rice)

           2. Atlas 66 ( High Protein content variety of wheat)

108. Hidden hunger :- Many people are able to get food which contains only carbohydrates.These people do not get other nutrients like protein, vitamins and minerals. This condition is called ‘Hidden hunger’ i.e. consumption of food deficient in nutrients especially micronutrients, protein and vitamins is called Hidden hunger.

109. Plant Breeding:- The purposeful manipulation of plant species in order to create desired plant types that are better suited for cultivation,give better yield and are disease resistant is called plant breeding.