Category: Maharashtra State Board Notes

By going through these Maharashtra State Board Class 12 Geography Notes Chapter 3 Human Settlements and Land Use students can recall all the concepts quickly.

Maharashtra State Board Class 12 Geography Notes Chapter 3 Human Settlements and Land Use

→ Man being a social animal, likes living in groups.

→ Due to social bonding and social needs many people come together and construct houses, which is known as settlement.

→ Development of settlement have co-relation between man and environment.

→ Type and spacing of settlements depend upon many physical factors like relief, soil, climate, drainage, groundwater level etc.

→ Social factors, sometimes are responsible for fragmentation of settlements.

Types of Settlement:

→ Settlements vary in their size and types ranging from hamlets to metropolitan city.

→ Type of settlement refers to some common features of the settlement.

→ Pattern of settlements refers to regular form in which series of things occur.

→ The term settlement pattern is strictly applied to the spatial arrangement or distribution of settlement within the given area.

→ On the basis of functions, there are two types of settlement – rural and urban.

→ Cities can be divided on the basis of their function.

→ Some cities specialise in certain functions, activities, products or services.

→ On the basis of specialisation of some important functions, Indian cities can be classified as follows:
Pimpri – Chinchwad as industrial town, Khadki as cantonment town, Pune as educational centre and Kolhapur, Pandharpur as religious town etc.

→ As town becomes city and city becomes metro cities, lots of changes can be seen in them in their form, land uses and structure.

→ As cities grow in their size, there is change in their skyline.

Land Use Classification:

→ Land use in rural areas is different from urban areas.

Land use and Landcover:

→ Land cover describes the physical surface covering the land like forest, water, sand, ice, rocks, etc.

→ Land use describes the use of the land; use might be recreational, but land cover might be forest or vegetation.

→ Land cover can be determined by analysis of satellite imagery, but the land use cannot be determined from the satellite imagery.

Urban-Rural Fringe:

→ The area between urban and rural area is called urban-rural fringe. It has both the urban and rural characteristics.

→ It is a transition zone between urban and rural area.

→ People from this area daily travel to central area for their work.

→ Here, we have a mixture of rural and urban land use.

→ The city and the surrounding areas consist of two administrative areas – Municipal Councils and Gram Panchayats.

→ Smaller municipal towns lose their identity, though they are geographical part of the city.

→ Town far from the main city maintain its distinct identity and have problems relating to the urban amenities and transportation.

→ The quality of available services is generally inferior.

→ Agricultural land may have been converted to residential or industrial areas or entire area may be rural.

→ Beyond urban fringe, there is a rural fringe. Rural fringe consists of only villages partly affected by the urbanisation.

Suburbs:

→ Outside metropolitan cities, there might be small towns or number of well-developed cities or towns. Such cities or towns are suburbs of Mumbai.

→ Andheri, Goregaon, Bhandup, Mulund, Thane, Kalyan etc., are suburbs of Mumbai.

→ All these suburbs developed as a result of the growth and development of Mumbai.

By going through these Maharashtra State Board Class 12 Geography Notes Chapter 2 Population Part 2 students can recall all the concepts quickly.

Maharashtra State Board Class 12 Geography Notes Chapter 2 Population Part 2

→ The population is considered a human resource. Its physical and intellectual characteristics affect the development of any region/country.

→ Economic activities develop only with reference to human resources. In the absence of proper use of human resources, other resources are not developed effectively.

→ While studying population composition, we study, age structure, sex, literacy, education, and occupational structure.

Population Composition:

Age Structure

→ Age structure refers to the number of people in different age groups such as infants, children, teenagers, young, adult and old people.

→ Share of each age group in population varies from country to country.

→ Age structure of population can be studied with the help of population pyramid.

→ While drawing population pyramid, age group is taken on Y-axis in the centre and on X-axis population or percentage of population in different age group. On left side of graph is male population and right-side female population.

→ The base of the graph shows children population and apex shows old population.

→ Population in the age group 15-59 years indicate group of working population i.e., economically active population.

→ Population in the age group 0-15 years indicate dependent population or economically inactive population.

→ Population in the age group above 60 years, indicates greater expenditure on medical and health facilities since population in this age group is economically dependent.

Types of population pyramid

→ Expansive – Broad base with tapering top. This shows high birth rate and high death rates.

→ Constructive – This pyramid has narrower base and broader apex. It indicates lower percentages of younger population and more elderly population. It also shows lower birth rates and lower death rates.

→ Stationary – Population in almost all age groups is same. Very low birth and death rates. There is hardly any population growth.

Sex Composition:

→ Population pyramid gives us idea about number of men and women in different age groups.

→ The ratio between number of men and women in population is called sex ratio.
Sex Ratio = \(\frac{\text { Total Female Population }}{\text { Total Male Population }}\) ×1000

→ The sex ratio gives us important information about the status of women in a country.

→ Average sex ratio of the world population is 990 females per 1000 males.

→ Countries like Latvia, Estonia, Russia and Ukraine have the highest sex ratio in the world. (1162 females per 1000 males)

→ On the other hand, in Saudi Arabia, there are 667 females per 1000 males.

Demographic Dividend:

→ The growth in an economy as a result of a change in the age structure of a country’s population is known as Demographic Dividend.

→ The change in demographic dividend comes because of a decline in birth and death rates.

→ As birth rate decreases, the number of young dependent population decreases.

→ Economic productivity of a country depends upon the ratio between working and dependant (non-working) population.

→ Higher the ratio, higher is the contribution of working population in the economy.

→ With fewer people to support and more people working, economy’s resources are invested in other areas to accelerate a country’s economic development.

→ Per capita income increases.

→ Demographic dividend depends on the proper implementation of policies in the areas such as education, health, research, etc.

→ It also depends on the level of schooling, employment, frequency of childbearing, economic policy on tax incentives, health, pension, and retirement policies.

Literacy and Education

→ An important indicator of socio-economic development is the proportion of literate population of a country.

→ The standard of living, social status of females, education facilities, government policies reveal socio-economic development of a country.

→ Population above 7 years of age, who can read, write and have the ability to do simple arithmetic calculations with understanding is considered as a literate person in India.

Occupational Structure:

→ Population of men and women in the age group 15-59 years are considered as working population.

→ Working population take part in primary, secondary, tertiary and quaternary occupations.

 

Rural and Urban Composition:

→ On the basis of residence, population is divided into Rural and Urban.

→ Lifestyles of people living in rural and urban areas is different, which is based upon their livelihood and social conditions.

→ Age and sex composition, occupational structure, density and level of economic development are different in rural and urban areas.

→ The areas in which very large proportion of population engaged in primary occupations are considered as rural.

→ The areas in which large proportion and working population engaged other than primary occupations are considered as urban.

Migration:

→ Movement of people from one place to another, from one country to another, for lesser or longer period or permanently is called migration.

→ Migration also can be voluntary or non-voluntary.

→ Migration changes density patterns and structure of population in both donor as well as recipient region.

 

Impact of migration on population :
Donor region:

→ Out migration from donor region causes no utilization of existing facilities/services like housing, water supply, transportation, health facilities, education, recreation etc.

→ Expenditure incurred to develop these facilities goes to waste.

→ Age and sex structure changes tremendously. For example, in Kerala, sex ratio of 1,084 female per 1000 male population in working-age group.

Recipient regions

• Recipient region experiences tremendous pressure on the available facilities.
• In this region housing, water supply, transportation, medical, education facilities are becoming insufficient due to increasing population.
• Agricultural land is converted into non – agricultural activities, such as housing.
• Land prices increase tremendously. Lack of housing leads to the development of slums.
• There is a shortage of public services, increased economic inequality and crime rate.
• There will be unfavourable sex ratio e.g., Mumbai 832 and Pune 948.
• Working-age population higher than non-working age group population.

By going through these Maharashtra State Board Class 12 Geography Notes Chapter 1 Population Part 1 students can recall all the concepts quickly.

Maharashtra State Board 12th Geography Notes Chapter 1 Population Part 1

→ Population Geography is a branch of Human Geography.

→ In this branch, we study quantitative and qualitative composition of population, how population influences the economy and development and much more.

→ The distribution of population in the world is uneven.

→ Asia has 30% landmass and supports 60% of the world’s population.

→ Number of people living in a unit area is called density of population.

→ Density of population = \(\frac{\text { Total population }}{\text { Total area (sq. km) }}\)

Components of population change:

→ People from one region differ from another region. They can be distinguished from one another on the basis of age, sex, place of residence, occupation and life expectancy.
Population growth :

→ Population growth is the change in number of inhabitants of a territory during specific period of time.

→ Growth of population can be expressed either in terms of absolute number or in percentage.

→ Change of population is an economic indicator of development and social upliftment.

→ Birth rate (BR), Death rate (DR) and Migration are three components of change of population.

Crude birth rate:

Number of live births in a year per thousand population is known as crude birth rate (CBR).
CBR = \(\frac{\text { Total number of live births in a year }}{\text { Total population in that year }}\) × 1000

Crude death rate

→ Number of deaths in particular year per 1000 population is known as crude death rate.
CDR =\(\frac{\text { Total number of deaths in a year }}{\text { Total population in that year }}\) × 1000

→ Population growth in any region occurs not only by increasing birth rate but also because of decreasing death rate

The Theory of Demographic Transition:

→ No country experiences the same rate of growth or decline of population.

→ Population growth or decline changes with the economic development, tendencies of birth rate and death rate.

→ The theory of demographic transition is based on the population trends of a country with time.

→ Any country passes through different stages of population growth.

Stages of Population Growth :

Stage 1 High stationary stage :

• High birth and death rates
• Stable population
• Poor financial position
• People engage in primary activities like agriculture
• Limited educational opportunities
• Big families
• Poor science and technological development
• Poor sanitation facilities, malnutrition and high death rate.

Stage 2 Early expanding stage

• Development of medical and health care services
• Control and combat diseases
• Reduction in mortality rate
• Constant birth rates
• Rapidly growing population
• Efforts to control population
• Increase in agricultural and industrial production.

Stage 3 Late expanding stage

• Decreasing death rates
• Decreasing birth rates
• Reduction in population
• Income of the people is slightly above subsistence level
• Slight increase in the standard of living hence, decreasing poverty
• Rise in technological growth
• Expansion of secondary and tertiary activities
• Increased education facilities, awareness of family planning

Stage 4 Low stationary stage

• Decrease in birth rate
• High standard of living
• Improved economic condition of the country
• Improved economic status of the people
• Increased engagement in secondary and tertiary activities
• Better medical facilitates, hence, low death rates
• Epidemics under control
• Health-conscious

Stage 5 Declining stage

• Equal birth rate and death rate
• Minimum population growth and negative in some countries
• Reduced population due to higher mortality
• Percentage of children is lower than elders
• Most of the country’s income comes from tertiary activities
• Best quality education and health facilities
• Healthy environment and pleasant life

By going through these Maharashtra State Board Class 12 Economics Notes Chapter 2 Utility Analysis students can recall all the concepts quickly.

Maharashtra State Board Class 12 Economics Notes Chapter 2 Utility Analysis

Meaning of Utility:
Utility means want satisfying power of a commodity. It is a capacity of a good to satisfy human want.

Features of Utility:

• Utility is a subjective concept.
• Utility is a relative concept.
• Utility differs from usefulness.
• Utility differs from pleasure.
• Utility and Satisfaction are interrelated but they are not same.
• Utility depends upon intensity (urgency) of want.
• Utility is the basis of Demand.
• Utility is morally colourless.
• Utility is multi-purpose.
• Utility is not cardinally measurable.

Types of Utility:

Types of Utility	Example
(1) Form Utility	Furniture made of wood, toys from clay
(2) Place Utility	Woollen clothes in cold regions
(3) Service Utility	Teacher teaches to student, lawyer’s advice to client
(4) Knowledge Utility	Getting or acquiring knowledge about functions
(5) Possession Utility	Transfer of goods from sellers, to buyers.
(6) Time Utility	Books during examination

Concepts of Utility:

→ Marginal Utility (M.U.): It refers to an additional utility derived by a consumer from each unit of commodity consumed. It is the addition made by last unit.

→ Total Utility (T.U.): It refers to sum of utilities derived by a consumer from all units of commodity consumed. It is an aggregate of marginal utilities.

Relationship between M.U. & T.U.:

Law of Diminishing M.U:
It explains economic behaviour of a rational consumer. It was first proposed by Prof. Gossen, but later, it was explained in detail by Prof. Alfred Marshall in his book “Principles of economics” in 1890.

Statement of the Law of DMU:
“Other things remaining constant, the additional benefit, which a person derives from a given increase in his stock of a thing, diminishes with every increase in the stock that he already has.” In simple words, MU goes on diminishing with every successive unit of commodity consumed.

Assumptions of the Law:

• Cardinal measurement
• Homogeneity
• Rationality
• Continuity
• Reasonability
• Divisibility
• Constancy
• A single want

Tabular Presentation Schedule:

Units of Commodity	Marginal Utility (M.U.)
1	10
2	8
3	6
4	4
5	2
6	0
7	-2

Graphical Presentation Diagram:

Exceptions to the Law of DMU :

• Hobbies
• Miser
• Money
• power
• money
• Reading
• music

Criticisms of the Law of DMU:

• Unrealistic assumptions
• Cardinal measurement – not possible
• Not applicable to indivisible goods
• Constant MU of money
• Restricted to a single want

Significance of the Law of DMU:

• Useful to consumers to maximise satisfaction.
• Useful to Government in framing various policies.
• Helps us to understand the paradox of value.
• Basis of Law of Demand.

Relationship between MU & Price:

A rational consumer attains equilibrium where MU_x = P_x. So, a consumer will buy 3 units.

Two English Economists:
J. R . Hicks & R. G. D. Allen were the two main exponents of In difference Method. It adopts the concept of ordinal utility.

By going through these Maharashtra State Board Class 12 Economics Notes Chapter 1 Introduction to Micro and Macro Economics students can recall all the concepts quickly.

Maharashtra State Board Class 12 Economics Notes Chapter 1 Introduction to Micro and Macro Economics

Meaning of Micro Economics:
Microeconomics deals with small individual economic units such as an individual consumer, individual producer, the price of a particular commodity or factor, etc.

Definition of Micro Economics:

→ According to Maurice Dobb – “Microeconomics is in fact a microscopic study of the economy. ”

→ According to Prof. A.P.Lerner – “Microeconomics consists of looking at the economy through a microscope as it were, to see how the millions of cells in the body of economy – the individuals or households as consumers and individuals or firms as producers play their part in the working of the whole economic organism.”

Scope of Microeconomics:

→ Theory of Product Pricing: The price of each commodity is determined by the forces of demand and supply. Microeconomics is a study of demand analysis i.e. individual consumer behaviour and supply analysis i.e. individual producer behaviour.

→ Theory of Factor Pricing: There are four main factors contributing to the production process which are land, labour, capital and entrepreneur. Microeconomics helps in determining the factor rewards like land gets rent, labour gets wages, capital gets interest and entrepreneur gets profit.

→ Theory of Economic Welfare: This theory deals with efficiency in allocation of resources which aim at maximum satisfaction of people. Three economic efficiencies are as follows :

• Efficiency in production: It means producing maximum amount of goods and services from given amount of resources.
• Efficiency in consumption: It means distribution of produced goods and services to the society for consumption in such a way to have maximum total satisfaction of people.
• Overall economics efficiency: It means to produce those goods and services which are most desired by the people.

Features of Micro Economics:

→ Study of Individual Units: Microeconomics deals with the study of behaviour of small individual units of the economy such as individual consumer, individual firm, individual industries, individual prices, etc.

→ Price Theory: Micro economics is known as price theory because it determines the prices of goods and services as well as prices of factors of production.

→ Partial Equilibrium : Micro economics analysis deals with partial equilibrium which analyses equilibrium position of an individual economic unit i.e. individual consumer, individual firm, etc.

→ Based on Certain Assumptions: Micro economics is based on ‘ceteris paribus’ assumption i.e., other things remaining constant like full employment, laissez faire policy, perfect competition, pure capitalism, etc.

→ Slicing Method: It divides or slices the economy into small units and studies each unit in detail e.g. study of a particular household demand in detail.

→ Use of Marginalism Principle : The term ‘marginal’ means change brought in total by an additional unit. Marginal analysis helps to study a variable through the changes by which producers and consumers take economic decisions using this principle.

→ Analysis of Market Structure: Microeconomics analyses different market structures such as perfect competition, monopoly, monopolistic competition, oligopoly, etc.

→ Limited Scope: The study of microeconomics is limited to individual economic unit only. It does not deal with macro problems like unemployment, inflation, deflation, poverty, unemployment, population, etc.

Importance of Micro Economics :

→ Price Determination: Microeconomics explains how the prices of different products and various factors of production are determined.

→ Free Market Economy: A free market economy is that economy where the economic decisions are taken at individual levels without intervention by the government. Decisions are regarding production of goods such as What to produce? How much to produce? How to produce? etc.

→ Foreign Trade: Microeconomics also explains gains from foreign trade, effects of tariffs, factors affecting exchange rate, etc.

→ Economic Model Building: Microeconomics helps in understanding various complex economic situations with the help of economic models.

→ Business Decision: Microeconomic theories are helpful to businessmen for taking important business decision related to determination of cost of production and prices of goods, maximization of output and profit, etc.

→ Useful to Government: It is useful in formulating and evaluating economic policies including pricing and distribution policies that promote economic welfare. It is useful in determining tax policy, public expenditure policy, etc.

→ Basis of Welfare Economics: It explains how optimum use of resources can be made to increase the welfare of the society. It also studies how taxes affect social welfare.

Meaning of Macro Economics: Macroeconomics is the study of aggregates which analyses the entire economy, such as national income, total employment, total consumption, inflation, total savings, etc.

Definition of Macro Economics:

→ J. L. Hansen: “Màcro economics is that branch of economics which consider the relationship between large aggregates such as the volume of employment, total amount of savings, investment, national income, etc”

→ Prof. Carl Shapiro: ‘Macroeconomics deals with the functioning of the economy as a whole.”

Scope of Macro Economics:

→ Theory of Income and Employment: It explains which factors determine the level of national income and employment and what causes fluctuations in the level of income, output and employment.
By studying the consumption function and investment function, we can understand how the level of employment is determined in the economy.

→ Theory of General Price Level and Inflation: Macroeconomic analysis shows how the general price level is determined and explains the causes for fluctuations in it. This study is important for understanding the problems created by inflation and deflation.

→ Theory of Economic Growth and Development: Macroeconomics studies the causes of underdevelopment and poverty in poor countries and suggests strategies for accelerating the growth and development in the country.

→ Macro Theory of Distribution: Macro theory of distribution deals with the relative share of rent, wages, interest and profit in the total national income of various classes.

Features of Macro Economics:

→ Study of Aggregate: Macroeconomics deals with the study of entire economy. It studies the overall conditions in the economy such as National Income, National Output, Total Employment, General Price levels, etc.

→ Income Theory: Macroeconomics studies the concept of National Income and causes of fluctuations in the National Income that lead to business cycles i.e. inflation and deflation.

→ General Equilibrium AnalysÍs: Macro Economics analysis is based on general equilibrium which deals with the economic system as a whole and studies the interrelationship between the various macro variables in an economy. General equilibrium deals with the behaviour of demand, supply and prices in the whole economy.

→ Interdependence: There is an element of interdependence among the macroeconomic variables such as income, output, employment, investment, price level, etc.

→ Lumping Method: Lumping method is the study of the whole economy rather than in part. It considers aggregates like National Income, Total consumption, etc. instead of personal income, PCC, etc.

→ Growth Models: Macroeconomics studies various factors that contribute to economic growth
and development. These growth models are used for studying economic development.

→ General Price Level: Macroeconomic studies the determination and changes in general price level which is the average of all prices of goods and services currently being produced in the economy.

→ Policy-Oriented: Macroeconomics is a policy-oriented science which is useful in formulating economic policies to promote economic growth, to control inflation and depression, to generate employment, etc.

Importance of Macro Economics:

→ Functioning of an Economy: It given an idea of functioning of an economic system and help us to understand the behaviour pattern of aggregate variables.

→ Economic Fluctuations: It help to analyse the causes of fluctuation in Income, output and employment.

→ National Income: It helps to study about NI and made possible to formulate correct economic policies.

→ Economic Development: It helps us to understand the problems of the developing countries such as poverty, difference in the standards of living etc., and suggest important steps to achieve economic development.

→ Performance of an Economy: It helps us to analyse the performance of an economy where Ni estimates are used to measure the same.

→ Study of Macro Economic Variables: Study of macroeconomic variables are important to understand the working of the economy.

→ Level of Employment: Macroeconomics helps to analyse the general level of employment and output in an economy.

By going through these Maharashtra State Board 12th Science Biology Notes Chapter 3 Inheritance and Variation students can recall all the concepts quickly.

Maharashtra State Board 12th Biology Notes Chapter 3 Inheritance and Variation

Chromosomes and Mechanism of inheritance-

1. Heredity or inheritance : The transmission of genetic information from generation to generation.
2. Gregor Mendel : He used hybridization techniques and gave explanation for heredity.
He postulated principles of heredity.
3. Correns was other contemporary German botanist.

Note : Carl Correns discovered principles of heredity independently and verified work of Mendel by experimenting on other model organisms. He did not propose fundamental laws of heredity as mentioned in textbook. Laws of heredity were given by Mendel.

4. Mendel gave the term factors, which is now 5 known as genes.

5. Reasons for Mendel’s success :

• Carefully planned experiments.
• Large sample of study. Meticulous recordings which gave the ratios.
• Well-chosen contrasting characters which were recognizable.
• Each character controlled by single factor.
• Dominance and recessiveness among the pair of characters.

6. Seven pairs of contrasting characters of pea plant studied by Mendel were :

Character	Dominant	Recessive
Seed shape	Round	Wrinkled
Seed colour	Yellow	Green
Pod shape	Inflated	Constricted
Pod colour	Green	Yellow
Flower colour	Purple	White
Flower location	Axial	Terminal
Plant height	Tall	Dwarf/Short

Genetic Terminology-

• Character : Specific feature that an organism possesses.
• Trait : An inherited character with its variant form that can easily be seen. E.g. Tall or dwarf.
• Factor : Unit of heredity responsible for the inheritance and expression of a genetic character. Initially considered to be in a particulate form.
• Gene : Specific segment of DNA responsible for the inheritance and expression of that character.
• Alleles or Allelomorphs : The two or more alternative forms of a given gene (factor). They are present on the identical loci on homologous chromosomes.
• Dominant : An allele capable of expressing its trait even in the presence of an alternative allele is called a dominant allele. In heterozygous condition, dominant ones always show their expression. E.g. T allele.
• Recessive : An allele that is not expressed in the presence of an alternative allele is called recessive allele. In heterozygous condition, they are never expressed. They are expressed only when they are in homozygous condition. E.g. T allele.
• Phenotype : The external appearance of an organism which can be easily seen for any trait is called its phenotype. E.g. Tallness or dwarfness of pea plant. The ratio of phenotypes, i.e. external appearance of offspring produced in F₂ and subsequent generation. E.g. 3 Tall: 1 dwarf is phenotypic ratio in monohybrid cross.
• Genotype : Genetic constitution of an organism which decides the trait is called genotype. E.g. TT / Tt / tt are genotypes. The ratio of genotypes produced in the F₂ and subsequent generation is called genotypic ratio. E.g. 1 TT : 2Tt : 1 tt. (1:2:1 is genotypic ratio for monohybrid cross.)
• Homozygous (pure): In homozygous condition, there are identical alleles for a particular trait. Homozygous produces only one type of gametes. E.g. TT (tall) or tt (dwarf).
• Heterozygous: In heterozygous condition, there are pairs of contrasting alleles for a particular trait. Heterozygous or hybrid produces two types of gametes, E.g. Tt.
• Pure line: An individual or a population which is homozygous for one or more traits, is called pure line.
• Monohybrid: When one trait is considered during inheritance, it is called monohybrid. A cross considering only one heritable trait is called monohybrid cross. E.g. cross of pure tall and pure dwarf plants.
• Dihybrid: When two traits are considered during inheritance, it is called dihybrid.
  A cross between parents differing in two heritable traits, is called dihybrid cross.
• F1 generation / First filial generation: First generation formed by mating of pure parents having contrasting characters. E.g. Progeny of TT x tt.
• F₂ generation: Generation obtained by self¬breeding F₁ organisms, is called F₂ generation. E.g. Progeny of Tt x Tt.
• Punnett square/checker board: A probability table representing different permutations and combination of fertilization between gametes of the opposite mating types.
• Homologous Chromosomes: Identical chromosomes which are morphologically, genetically and structurally similar are homologous chromosomes.
• Back cross: A cross of F₁ progeny with any of the parents (e.g. F₁ tall x pure tall; F₁ tall x pure dwarf i.e. Tt x TT or Tt x tt).
• Test cross: A cross of F₁ progeny with homozygous recessive parent
  (e.g. F₁ tall x pure dwarf i.e. Tt x tt).

 Mendel’s Laws of Inheritance-

• Law of Dominance: When two homozygous individuals with one or more sets of contrasting characters are crossed, the alleles (characters) that appear in F₁ are dominant and those which do not appear in F₁ are recessive.
• Law of segregation or Law of purity of gametes: When ₁ hybrid forms gametes, the alleles segregate from each other and enter in different gametes. The gametes formed are pure because they carry only one allele each (either dominant one or recessive one.)
• Law of Independent Assortment: When hybrid possessing two (or more) pairs of contrasting factors or alleles forms gametes, the factors in each pair segregate independently of the other pair.

Back cross Test cross-

• Back cross: Back cross is the cross between F₁ individual with one of the parent. (Either recessive or dominant).
• Test cross: Test cross is the cross of F₁ hybrid with the homozygous recessive parent.

Deviations from Mendel’s findings-

I. Mendel’s experiments gave the following generalizations:

• Single trait due to single gene which has two alleles.
• Two alleles interact with each other in which one allele is completely dominant.
• Factors or genes for different traits are present on different chromosomes and they show independent assortment.

2. Later, different deviations were noted by the scientists who worked in post-Mendelian era. These findings form Neo-Mendelism.

3. The deviations from Mendel’s findings are of following types:

• Phenomena of co-dominance and incomplete dominance: Shown by single trait due to single gene but its two alleles show interactions.
• Multiple allelism: Single trait shown by single gene which has more than two alleles.
• Polygenic inheritance: Single trait due to more than one gene which show interactions which are either epistastic or additive effect.
• Pleiotropy: Many traits which are influenced by a single gene.

4. Gene interactions: When phenotypic expression of a gene is modified or influenced by the other gene, then it is called gene interactions.

• Intragenic interactions: Interactions between the alleles of same gene. E.g. incomplete dominance and co-dominance. Also seen in the multiple allele series of a gene.
• Intergenic (non-allelic) interactions: Interactions between the alleles of different genes present on the same or different chromosomes E.g., Pleiotropy, polygenes, supplementary and complementary genes.

5. Incomplete dominance: When both the alleles express themselves partially then it is called the incomplete dominance. Unlike as in complete dominance, here one allele cannot completely suppress the expression of the other allele. Thus there is formation of an intermediate expression in the F₁ hybrid.
E.g. the flower colour of Mirabilis jalapa.

• Red-flowered (RR) plant x White-flowered (rr) plant,
• F₁ offspring: Pink (Rr) flowers.
  Genotypic ratio – 1 RR : 2 Rr : 1 rr
  Phenotypic ratio – 1 Red : 2 Pink : 1 White

6. Co-dominance: When both the alleles of an allelomorphic pair express themselves equally in F₁ hybrids then it is called co-dominance. Alleles that express themselves equally independently in hybrids, are co-dominant alleles.
E.g. Coat colour in cattle.

• Red coat (RR) x white coat (W W).
• F₁ hybrids (RW) : Roan, (mixture of red and white). Both traits expressed equally.
  In F₂ generation red (RR) : roans (RW) : white (WW) =1:2:1.
• Co-dominance shows the genotypic and phenotypic ratios identical.

7. Multiple alleles :

• When more than two alleles of a gene in a population occupy the same locus on a chromosome or its homologue, then such alleles are called multiple alleles.
• Wild and original gene is mutated to form multiple alleles. There is a series of alleles which show dominance, co-dominance or incomplete dominance with the other recessive alleles among them. The most dominant is the wild type.

E.g. (1) Size of wings in Drosophila. From normal wings to vestigial wings (vg) in homozygous condition. (2) A, B, O blood groups in human beings.

8. Pleiotropy:

• Pleiotropic gene is the single gene that controls two {or more) different traits.
  This phenomenon is called pleiotropy or pleiotropism.
• Phenotypic ratio : 1 : 2 instead of 3:1 because of the death of recessive homozygote.
• E.g. Sickle-cell anaemia, is caused by a gene Hbs.

Normal or healthy gene is dominant : HbA
Heterozygotes are carriers (HbA/Hbs). They show signs of mild anaemia.
Homozygotes with recessive gene Hbs die due to severe anaemia.
Thus, the gene for sickle-cell anaemia is lethal in homozygous condition and produces sickle-cell trait in heterozygous carrier.

(4) TWo different expressions are produced by a single gene. A marriage between two carriers will produce normal carriers and sickle-cell anaemic children in 1 : 2 : 1 ratio.

Chromosomal Theory of Inheritance

• Hugo de Vries, Correns and von Tschermak, independently rediscovered Mendel’s work on the inheritance of traits in 1900.
• Walter Sutton and Theodore Boveri (1903) put forth theory of chromosomal theory of inheritance after studying behaviour of meiotic chromosomes.

Chromosomes
(Chromo = colour, soma = body)

1. Carriers of heredity, chemically they are made up of DNA, histone and non-histone proteins.

• The term ‘Chromosome’ was coined by W. Waldeyer (1888).
• Chromosome number is specific for every species.

2. Ploidy: The degree of repetition of the primary basic number of chromosomes (i.e. ‘x’) in a cell.

•  Euploidy : Euploidy is the condition in which the chromosome number in a cell is the exact multiple of the primary basic number.
• Euploids are further divided into monoploid/haploid (n), diploids (2n), triploids (3n), tetraploid (4n), etc.
• Aneuploidy : Aneuploidy is the condition in which the chromosome number shows either addition or deletion by one or more.

3. Structure of chromosome :
Parts of a typical chromosome :

• Two chromatids arms joined together at centromere. Chromatid arm bears long, unbranched, slender, highly coiled DNA thread called chromonema.
• Centromere or primary constriction : Has kinetochore. (Disk shaped structure at which i spindle fibres are attached during cell division.)
• Secondary constriction : At secondary constriction I, nucleolus becomes organized during interphase.
• A satellite body (SAT body) attached at secondary constriction II.
• Telomeres : The ends of chromosomes.

4. Types of chromosomes : Classified as per 5 the position of centromere :

• Acrocentric (j-shaped),
• Telocentric (i-shaped),
• Submetacentric (L-shaped) and
• Metacentric (V-shaped).

5. Sex chromosomes : Sex chromosomes or allosomes are responsible for the determination of sex.

Linkage and Crossing Over

1. Linkage :

• Tendency of two or more genes to be inherited together is called linkage. The genes showing linkage are called linked genes.
• Bateson and Punnett discovered linkage in ; plants.
• T. H. Morgan discovered linkage in animals.
• Types of linkage : Complete linkage and Incomplete linkage :
  (i) Complete linkage : E.g. seen in X chromosome of Drosophila males.
  (ii) Incomplete linkage : E.g. seen in colour : and shape of grain of Zea mays.
• Linkage Groups : All the linked genes in a particular chromosome.
• The number of linkage groups of a particular species is equal to its haploid number of chromosomes.

2. Sex – linkage and Sex – linked inheritance

3. Crossing Over:

• Process of formation of recombinations of genes by interchanging and exchanging the segments of non-sister chromatids of homologous chromosomes is called crossing over. Crossing over takes place in pachytene of prophase-I of meiosis.
• Morgan coined the term crossing over.
• The mechanism of crossing over : There are four sequential steps such as synapsis, tetrad formation, crossing over and terminalisation.
• Due to crossing over, variations are produced which act as raw material for natural selection and thus helps in evolution.

4. Morgan’s Experiments showing linkage and crossing over :

• (1) Drosophila melanogaster used for genetic experiments because :
  • Easily cultured in laboratory.
  • Life span is short of about two weeks.
  • High rate of reproduction.
• Morgan explained the principle of linkage, sex linkage and crossing over.
• According to his experiments :
  • Genes grouped on the same chromosome are strongly linked. Recombinations among them are only 1.3%.
  • Genes present far away from each other on chromosome are loosely linked and hence show more 37.2% recombinations.

Autosomal Inheritance-

• Somatic cells of humans have 23 pairs of ; chromosomes. (2n)
• 22 pairs are autosomes and 1 pair is sex chromosome.
• Autosomes are concerned with bodily characters while sex chromosomes decide the sex of the individual.
• Autosome linked traits show autosomal i inheritance. TWo types : (1) Dominant (Widow’s peak and Huntington’s disease) : (2) Recessive [Phenylketonuria (PKU), Cystic I fibrosis and Sickle-cell anaemia].

Sex-Linked Inheritance-

1. Sex-linked genes are present on non-homologous region of sex chromosomes.
2. Their inheritance is called sex-linked inheritance.
3. Types of sex-linked genes : X-linked genes, Y-linked genes and X-Y linked genes.

• X-linked (sex-linked) genes : Located on non-homologous region of X chromosome. X-linked recessive genes show criss-cross i inheritance. E.g. Haemophilia, colour ; blindness, night blindness, myopia, muscular : dystrophy, etc.
• Y-linked (Holandric) genes : Located on non- homologous region of Y chromosome. E.g. Hypertrichosis.
• X-Y-linked genes : Located on homologous : region of X and Y chromosome and hence : called incompletely sex linked genes. E.g.
  Total colour blindness, nephritis and retinitis pigmentosa.
• Red green Colour blindness : X-linked recessive disorder. Inability to distinguish red and green colours.
  Genotypes of male and female individuals for colour blindness are as follows :

4. Haemophilia (Bleeder’s disease): X-linked recessive disorder. Blood clotting does not take place due to lack of (VIII or IX) clotting factors in blood.
Genotypes of male and female individuals for haemophilia are as follows :

Remember : X^hX^h combination is lethal, such females do not survive.

Sex Determination-

1. Bisexual or hermaphrodite or monoecious : The organisms in which both types of sex organs exist in the same body.
2. Dioecious or unisexual : Organism has either male or female reproductive organs.
3. German biologist, Henking in 1891, gave the concept of “X-body”. It was later understood that it is X chromosome.
4. Sex Determination :

(1) Chromosomal :

Note : The diploid autosomal number may be different for different birds. It should be remembered as AA and not 2n (as given in Textbook page no. 65, Fig. 3.15). Because 2n will be diploid chromosome number including autosomes and sex chromosomes.

(2) Environmental : Seen in Bonellia viridis

• Larva grown in vicinity of adult female grows into male.
• Larva which drifts away from adult female grows into female.

Genetic Disorders-

Know your scientist :
Thomas Hunt Morgan

Contributions :

• Chromosomal theory of heredity
• Introduction of Drosophila in genetic research.
• Principle of linkage, sex linkage and crossing over.
• Key role in the field of genetics.
• Nobel prize for Physiology and medicine (1933)

By going through these Maharashtra State Board Class 11 Political Science Notes Chapter 7 Public Administration students can recall all the concepts quickly.

Maharashtra State Board Class 11 Political Science Notes Chapter 7 Public Administration

Introduction

In this chapter, we will deal with the meaning, scope and evolution of Public Administration. We will also study about the administrative system in India. Public administration implements policy. The administration of national, state and local government institutions is called public administration.
There are two aspects to public administration.

1. One is a general aspect. It focuses on the following:

• Planning the outline of things to be done.
• Creating a structure of organisation to implement the decisions.
• Appointing people to do the work.
• Coordinating the work to ensure that it is done properly.
• Provide the finance to do the activity.

2. The second is a specialised aspect. There are many specialised functions like maintaining law and order, providing education, ensuring public health, promoting agriculture, providing social security, etc. Each of these is a specialised activity requiring special skills for example, public health requires doctors, law and order requires police.

When the administration of these activities is carried out by the government, it is called public administration. Public Administration as a discipline was born in the United States. Woodrow Wilson was the first to emphasise the need for the study of public administration as a subject.

Public Administration

Meaning : Public Administration is a sub-discipline of Political Science. It focuses on ‘government in action’ i.e., implementation of government decisions, policies and programmes in the fields of social security and welfare, law and order, transport and communication, health and sanitation, etc.

The executive branch of government consists of the Political Executive (Council of Ministers) and Permanent or Non-political Executive or Bureaucracy.

Public Administration as a subject studies the activity and process of the government.
According to Dwight Waldo, ‘Public administration is the art and science of management as applied to the affairs of the State’.

Public Administration broadly includes the following –

• Activities of all three branches of government, especially that of the executive branch.
• Non-political public bureaucracy operating in a political system.
• Management of public affairs and policy execution.
• Concerned with public welfare and hence provides service and regulatory functions to the people to attain a good life.

Scope Of Public Administration
The scope of Public Administration can be studied as two categories.

(A) Narrow Perspective – It focuses on aspects related only with the executive branch of government. Gullick and Urwick sum up this view in the acronym POSDCORB to denote Planning, Organisation, Staffing, Directing, Coordinating. Reporting and Budgeting.

• Planning – Working out in broad outline or a blueprint of what is to be done and methods to be adopted for it e.g., NITI Aayog has adopted the approach of grassroots to national level for development.
• Organisation – Establishing the formal structure of authority through which work is delegated, defined and coordinated e.g., All India Services like IAS, I.P.S., etc.
• Staffing – Recruitment, training and working conditions of personnel e.g., in India this is through Union Public Service Commission (UPSC).
• Directing: Making decisions and issuing instructions and orders as administration is a continuous
  activity.
• Coordinating – Interrelating the work of various sections and parts of the organisation to eliminate overlapping of work or conflict over responsibility.
• Reporting – Reporting to superiors and higher authorities any information about on-going and /or completed tasks. This ensures responsibility and accountability.
• Budgeting – Refers to fiscal planning, control and accounting.

(B) Broad Perspective – This differs from the narrow, managerial view of public administration. It includes activities of all three branches of the government, their interrelationships; specialized government functions such as defence, finance, health care, etc., as well as collaborations with private groups e.g., NGO’s in providing services to the community. This view is concerned with techniques of administration (POSDCORB) as well as with substantive matters of administration.

According to Woodrow Wilson, ‘Administration is the most obvious part of the government — it is government in action, the most visible, operative side of the government.’

Evolution Of Public Administration

Since ancient times, various thinkers have contributed to administrative thought and practice for e.g., Kautilya’s — ‘Arthashastra’(a text on administration and political economy), Aristotle’s ‘Politics’ (in ancient Greece) and Machiavelli’s ‘The Prince’ (in medieval Italy)

In the 18th century, Cameralism in Germany and Austria was concerned with the systematic management of governmental affairs. It stressed on descriptive studies of the structure and procedures of public administration as well as professional training of public officials. George Zincke was the most distinguished scholar of this group.
Public administration as a separate subject of study originated in the USA mainly due to factors like.

1. Large scale organisations which arose due to industrialization.
2. Scientific Management Movement by Taylor.
3. Emergence of Welfare State where the government had to perform a variety of functions.

Woodrow Wilson’s celebrated essay ‘The Study of Administration’ (1887) laid the foundation for the systematic, separate study of public administration. He is regarded as ‘The Father of Public Administration’. He advocated politics – administration dichotomy i.e., separation of administration from politics. According to him politics is concerned with policy making while administration in concerned with implementation of policy decisions Wilson emphasized the need to increase government efficiency.

Today, the subject matter of public administration has expanded to include areas like comparitive studies, public policy, new public management and good governance.

Public Policy

Public policy refers to the new approach to understand aspects of government activities for public welfare that is beyond simple administrative activities e.g., Ayushman Bharat which aims to provide universal access to good quality health care in India.

Public policy can be understood in three steps.

• Policy Choice – Elected representatives, bureaucrats and others decide on which concerns of citizens to deal with. Various options available about how to deal with it and the formulation of a programme is also decided e.g., anti-malaria programme (its objectives and implementation).
• Policy Output – Actual implementation of the policy takes place and policy output is determined.
• Policy Impact (evaluation stage) – This involves assessment of the objectives to determine policy impact and any improvements if required.

Administrative System In India

The Indian Administrative System is a legacy of the British rule in terms of structural and functional aspects like centrally controlled administrative system, police and revenue administration, training procedures, etc. However, even before this, India had many instances of good administrative systems such as during the reign of Chandragupta Maurya, of Emperor Akbar and of Chhatrapati Shivaji Maharaj. The British implemented administrative measures through various acts like Indian Councils Act 1909, Government of India Acts (1919, 1935), Indian Police Act (1861) Local Self Government set up by Lord Ripon, establishment of Reserve Bank (1935), etc.

After Independence, the administrative system in India has been guided by constitutional ideals such ars Liberty, Justice and Equality.

The broad framework of the administrative system in India includes –

• Three level administrative structures i.e., at the National level, State level, Local level.
• Three branches of government i.e., Legislature, Executive, Judiciary.

At the National level: Work of the Central (Union) government is done by various ministries, headed by a Minister, below which is the administrative machinery e.g., Departments of Home, Finance, Defence, Health, etc. There are also institutions like NITI Aayog, U.P.S.C., N.H.R.C, Election Commission, etc., which require administrative staff.

At the State level : Here also, there are various ministries, commissions, institutions to carry out government work. So administrative staff is involved here too.

At the local level: This may be urban or rural types of administration.

Recruitment for all posts, at all levels is through competitive exams, conducted by various government bodies e.g., U.P.S.C. and Staff Selection Commission (at union level) public service commission in states e.g., M.P.S.C. All bureaucrats owe allegiance to the constitution and not to any political party. This is the principle of political neutrality.