Forest Tree improvement | Forest Genetics Resources

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Forest Tree improvement | Forest Genetics Resources

Forest Tree Improvement: Intro

As the size of the population increasing at very high pace day by day. The basic needs of human being are also increase on higher pace. To fulfill these need we can’t rely only on natural resources, or we need to improve the productivity of these natural resources. With the increase of population high pressure is generated on the forest ecosystem. Continuously, during  the second world war forests are exploited at very high pace with improved techniques but other technique to regenerate the forest are not invented as required. One of the step to increase the productivity of particular tree species or forest is Forest tree improvement. In this way we can select the desirable species which will fulfill the requirement of high wood and other forest resources and reduce the pressure on forests.

Mainly 3 terms are used in Tree breeding: Forest Genetics, Forest Tree Breeding and Forest Tree Improvement

  1. Forest Genetics: It is the Study of heredity and variation in the forest plant species.
  2. Forest Tree breeding: It is the Study of improving economically important characters in forest tree species.
  3. Forest tree Improvement: Application of genetics principles to the improvement and management of fores tree species. it is combination of silviculture and tree parentage to obtain or develop the characters for which we can get greatest overall return.

Major Problem which occurs in the Tree Improvement

  1. Time: When trees are compared with other crops or small plants, tree are long-living organism, which may require years to produce the desired traits. So, they take years to bear flower and seed. The tree breeder must adjust his procedure to compansate for this fact
  2. Use of Indirect Evidence: The characteristics of a trees are controlled by the gene of trees and with interaction of particular environment. Genetic Material can’t give information directly about the expression, it must be assessed by indirect means, i.e. by growing the offspring of the tree and observing the characteristics. Again long time of rotation of tree make the problem more complicated.
  3. Uncertainly and Need for Continuous Experimentation: Most of the tree improvement experiment follows the general rules. But if breeder or forester have to obtain additional gain, then he have to continuous Experimentation.
  4. Necessity of Seed Production: Reproduction by seed is a necessary part of any tree improvement work. Some trees are not grown their own seeds. Thus, a tree breeder needs to be concerned with seed production, and must often devote a part of his efforts to experiments on the stimulation of flowering and Fruiting.
  5. No come Back: If we grow a tree plantation we can’t replaced it in midway by other seeds because it leads to the high economic loss.
  6. Scarcity of Basic Genetic Information about Trees: Trees are not drawn under plantation as old as normal crop plants. So, in the crops we can get the highly improved narrow genetic base. But, in tree breeding we can get unimproved wild types that have a very broad genetic base, or with trees that have been selected for two or three generations at most.
General Steps in Tree Improvement Program:
  1. A determination of the species, or geographic source within a species, that should be used in a given area.
  2. A determination of the amount, kind and cause of variability within the species All variations among trees are result of 3 things
    1. the differing environment in which the trees are growing
    2. the genetic differences among trees and
    3. the interactions between tree genotypes and the environments in which they grow.
  3. A packaging of the desired qualities into improved individuals, such as to develop trees with combinations of desired characteristics.
  4. Mass producing improved individuals for reforestation purposes.
  5. Developing and maintaining a genetic base population broad enough for needs in advanced generations.
Other words about Tree improvement will comes in our next articles

Pine Tree

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Pine Tree

Pine :- General Introduction

Pine is any conifer in genus Pinus. The genus Pinus if of great ecological and commercial importance. It is very large genus with almost 126 species. Some othe tree genera contain even more species, but Pinus stands out on account of its geographical range and other characteristics.

Pine:- Etymology

The modern English name pine derives from Latin pinus, which some have traced to the Indo-European base pīt- ‘resin’ (source of English pituitary). Before the 19th century, pines were often referred to as firs (from Old Norse fura, by way of Middle English firre).

Pine:- Taxonomy

Family:- Pinaaceae, which in turn is the largest family with in the coniferales. Pines are the gymnosperms The Pine or Pinus having two main subdivision
  1. Diploxylon (hard Species): The Diploxylon includes species with 2, 3 or 5 needles per fascicles.
  2. Haploxylon (Soft Species): In Haploxylon all species contains the almost 5 needles. In Haploxylon cones are generally soft and elongated. Presence of single vascular bundles in needles.
The distinguishing features of pines are combination of cone characteristics (bract scales and ovuliferous scales becoming closely fused during cone development) and the secondary foliage comprising grouping of two, three or five needles into short shoots called  fascicles, with sheaths of soft scales at the bases (Exceptions: P. monophylla, P. krempfii).  Pine tree Branches are occurs in discrete clusters. Some species are monocyclic and some are polycyclic. Monocyclic produce only one cluster of branches on the bole per years, and polycyclic produce more than one cluster on bole per year. All the species are evergreen, although the longevity of foliage can range from under 2 years to well over 5 years. Pine Tree

Pine: Evolutionary History

Pinus or pine is quite an ancient genus. It is now thought to have evolved in the early-middle Mesozoic era, in the region that has now split, through plate tectonic movements, into eastern North America and western Europe.
Pine: General Ecology
  1. Site Requirement:
  2. Fire Ecology
  3. Human Impacts
Site requirement: Pines of different species grow in a very wide range of climate range from rainforest to grassland steppe. Pines can survive in some high mountain areas with low precipitation. In the northern hemisphere latitudinal range is extremely high which range from the equator to arctic circle. Pines are generally found on medium to low fertility Ssoil, but species still vary widely in their edaphic requirements. Symboic association in pines are very important because these association helps to grow pines in infertile soils. If Pines are grown in very highly fertile soils this very degrade the wood quality or wooden properties of the pine (except P. elliotti and P. contorta). Fire Ecology: Their are many strategies whereby different pine species are ecologically adapted to fires. Most pine species depend in some measure on fire for maintaining their ecological status. Fires are important for killing the weeds which competing the woody plants and retard their growth in some cases.  A Few pine species have a very different mechanism of fire resistance, which is more typical of certain hardwoods. this is based on an ability to resprout from the stem or lower bole after crown are killed by fire (P. canariensis, P. oocarpa and p. rigida). Human Impact Human impacts have been widespread and varied Many pine specie have been subject to largely uncontrolled exploitation. Clearig forest for agriculture has reduced many natural stands but sometimes only temporarily. Other indirect human impact is through introduction of browsing animals. Pine tree

Pine : Uses

  1. Wood: easy to use, as wawn timber, various panel productss, round produce, and pulp for paper and board products. Wood is easy to saw, work and nail and is usually easy to dry without serious degrade.
  2. Farming: In some cases pine are also used in farming. General rotational period of pine is 30 year
  3. Food: large seeds also called pine nuts, that are harvested and sold for cooking and baking. They are an essential ingredient of Pesto alla genovese.
  4. Medicine: Some pine species are used to make some important ingredients which are used in medicines.
 

What is Weather Forecasting and its importance

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What is Weather Forecasting and its importance

Weather Forecasting, its importance and components

Weather forecasting or Weather forecast is to predict the atmospheric conditions at a given site. With increase in the observatories and synoptic weather stations record more data of rainfall, temperature, radiation and wind helps to predict weather more accurately. Various organization across the world predict weather elements and forecast weather conditions. Accepted standards are developed for measuring, assigining values and codes for different nations. Observatories records information of different weather element on the basis of daily forcast, warning and weather report are prepared by regional forecasting centres. Regional centers also forecast weather which are known as weather bulletins. These bulletins provide information of onset of monsoon, duration, intensity and other adverse weather conditions.

Weather Forecasting Features

The features of weather forecasting are
  1. Proper recording of data
  2. Careful study of synoptic charts
  3. Search for similar situation from the historical data
  4. preparation of the weather condition charts
  5. drawing quick, correct and definite conclusions regarding future weather phenomenon.

Weather Components

Sunshine: Sunshine information is helps the farmers and other sector peoples to plan their future activites on basis of sunshine duration and intensity on a particular location. Eg. Farmers takes decision like harvesting of crops and drying the farm produce according to weather forecasting report of Sunshine. Precipitation: It is falling of water from sky in any form (Solid, liquid) with force of gravity. Rainfall is predicts in the forecast at a particular location when less than 1/3 of the specified area is expected to receive rain. Precipitation comprise of Rainfall, Fog, Snow fall and mist. Weather Forecasting Types
  1. Short Range: Duration of this forecasting is 1-2 days.
  2. Medium Range: Duration of Medium Range forecasting is 3-4 days to 2 weeks.
  3. Long Range: This forecasting are for periods of more than 4 weeks.
Methods of Forecasting
  1. Synoptic Method: In this method of Weather forecasting, detailed analysis of current weather reports from a large Area. The Current weather patterns are related with the past analogous situations and forecasts are prepared on the assumption that a current situation will behave on the lines of the past analogous situation.
  2. Statistical Method: In this Method of Weather forecasting, regression equations or other sophisticated relationships are established between different weather elements and the resulting climate. Normally, selection of predictions or weather parameters are based on a possible physical relationship with the predictants.
  3. Numerical Weather prediction Techniques: In this method atmosphere behavior is represented by a set of equations which based on physical laws governing air movement, air pressure and other information. Method is found suitable for medium range forecasts.
 

Forest Management | Notes of Forestry for IFoS Mains

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Forest Management | Notes of Forestry for IFoS Mains

What is Forest management

It is the practical application of the scientific technical and economics principles of forestry. Definition of Different types of yield
  1. Intermediate Yield: It is the material or cash returns obtained from time to time from a forest not organized for continuous production.
  2. Final Yield: All the material that counts against the prescribed yield and which is derived from the main felling in a regular forest
  3. Total yield: Sum of the standing volume of a crop plus the total volume removed in thinning.
  4. Normal yield: Yield obtained from normal forest.
  5. Sustained Yield: It is the regular, continuous supply of the produce to the fullest capacity of forest from a unit area.
  6. Progressive Yield: Productivity of soil and of the crop by silvicultural treatments, judicious tending and enrichment of forest by changing the crop composition and by replacement of original inferior forest by valuable forest Species.
  What is Rotation? It is the planned number of years between the formation or regeneration of a crop and its final felling. it is the age of the plant beyond which deterioration of quality occurs. The length of Rotation is Depends upon the following
  1. Rate of growth of species: Generally fast growing species have shorter rotation period and vice versa.
  2. Silvicultural characteristics of the species: Some species are fast grower and some are slow grower.
  3. Soil types: Fertile soil will produce better crop in shorter period and vice versa.
  4. Economic considerations: Rotation period will vary according to the money value and changes in wood prices.
  5. Social Conditions: Market price, Personal needs and others factors.
  Types of Rotation
  1. Physical rotation: It is the rotation which coincides with the natural lease of life of a species on a given site. It is applicable to protection and amenity forest, park lands and road side avenues.
  2. Silvicultural rotation: it is the rotation through which a species is retained until satisfactory vigour of growth and reproduction on a given site.
  3. Technical Rotation: It is rotation in which a species yield the maximum material of a desired size for economic conversion or for special use.
  4. Rotation of Maximum volume production: It is the rotation that yields the maximum annual or net revenue irrespective of the value of the forest.
  5. Rotation of highest income: It is the rotation which yields the highest average annual gross or net revenue irrespective of the value of the forest.
  6. Financial rotation: It is rotation which yield the highest net return on the capital invested.
 

What is Normal Forest?

A forest which have Normal series of age gradation, Normal growing stock and Normal increment. Normal series of age gradation: it is the presence of tree of all ages from one year old to rotation age in forest. Normal growing stock: It is the volume of stands in a forest with normal age gradations or age gradation and normal increment. Normal Increment: It is best or maximum increment attainable by a given species and for a given rotation. How we can obtain the Normal Forest under different Silvicultural system?
  1. Clear felling system: In it, the total area is divided into number of coupes which is equal to A/R. The number of the coupe is equal to number of years in rotation (R). Here A is Area and R is Rotation years.
  2. Shelter wood systems: In it Total area is divided into number of regeneration blocks. The number of periodic block is equal to rotation divided by regeneration period (R/P). Each block will have single age class because each regeneration block is harvested and regenerated within the regeneration period.
  3. Irregular forest: In it, age class distinction is difficult because each unit area have trees of all the age classes. In this exploitable diameter is used instead of rotation age. So it is essential that every year we have to harvest all trees which attained the exploitable diameter all over the area.

Silviculture, its definition and Significant in Forest

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What is Silviculture

First, a question is comes in our mind, in actual what is silviculture. Different definition gives different definition about the silviculture some of them are given below

Difinition of silviculture By, Champion and Seth, 1968

The term silviculture refers to certain aspects of theory and practice of raising forest crops.

Difinition of silviculture By, Anon 1966

It is defined as the art and science of cultivation forest crops.

Difinition of silviculture Smith 1976

It is concerned with the technical details of crop production and defined as the art of producing and tending a forest or the theory and practice of controlling forest establishment, composition and growth. Silviculture contains two words silvics and culture. Silvics has been defined as the study of life history and generally characteristics of forest trees and crops with particular reference to environmental factors (Anon, 1966). Culture means its practical application or cultivation. So, Full means of Silviculture is Cultivation of Trees if we say it in simple words.

Objective of Silviculture

The study of silviculture is very important. Silviculture is improved limitation of nature. In nature, we find a large number of species coming up at one place. Some individuals die out of competition, some attain top canopy while others remain at lower levels. Silvicultural factors are usually controlled by economic considerations. 1. Produce High-Quality Timber If the Forest is not properly managed then the timber produced, is malformed and up to the quality match which in market required. By using the Silvicultural techniques the Forest land is protected from diseases, Insect-pest attacks, and major damaging agencies. 2. Increase productivity Productivity is the production of crop per unit area of land. If the productivity of the forest is low then revenue from that forest will also decrease. So, some silviculture techniques are used to increase the productivity of forest or tree land. 3. Reducing the Rotation of Trees species The major concern in the tree cultivation is rotational period. The time period required to properly mature the timber is very high as compared to other agriculture crops. With the adjustment in the density of forest trees, we can manage the rotational period of the trees. 4. Help in improvement of Afforestation programs There is a large area of forests which is blank or under stocked due to fire, encroachments, illicit fillings, or some natural causes. These areas are, however, suitable to bear tree growth. Silviculture helps us to afforest these areas with suitable trees by planting or by seedling. Silviculture guides to know the best period of seed collection, nursery technique, plantation details, etc. to complete afforestation. 5. Protection of Sites The main object of silviculture is to provide maximum protection to the site so that intangible returns from the forests are ensured. Important intangible returns include moderating climate, increasing precipitation, reducing soil erosion and floods conserving soil and water increasing water yields providing shelter to a large number of wild animals, etc. Silviculture helps to understand the requirement of a tree and its effect on the site. The species, which are likely to deteriorate the site, are discarded. Only such species which afford complete protection to the site and ensure a continuous flow of intangible benefits are preferred. 6. Facilitate Management and Use of Forests In unmanaged forests, good forests exist in difficult areas, where it is difficult to manage and harvest the timber. In managed forests, it is easy to plant the growth and distribution of forests so that the produce is used efficiency and economically. It is possible to arrange the forest in different localities in such age classes and species composition that management becomes easy. Practices of Silviculture There are many practices are done in lifetime of tree for improvement. Some of them are given only in short below
  • Tending operation
  • Pruning
  • Thining
  • Tending operation
  • Weeding
These all the operation will be given in details in our next Articles.

How to Score 7+ in IELTS | #1

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In this Series of Score 7+ we will publish tips and tricks with study resource to Score higher in the IELTS Exam. The Most Important Thing Before Start is to know the Pattern of the Exam. Below is given pattern of Exam.

IELTS Exam Structure

  1. Listening (Number of Question : 40, Time: 30 min) (Easy, Student can easily get 7+ Score)
  2. Writing (Medium)
  3. Reading (Number of Question : 40, Time: 60 min) (Easy)
  4. Speaking : (Time (10-15) (Difficult)
Details About these Four Sections of IELTS

  1. Listening

There are 6 types of Task in Listening part of Paper Task 1. In multiple choice tasks, there is a question followed by three possible answers, or the beginning of a sentence followed by three possible ways to complete the sentence. Test takers are required to choose the one correct answer – A, B or C. Sometimes, test takers are given a longer list of possible answers and told that they have to choose more than one. In this case, they should read the question carefully to check how many answers are required. Task 2 Test takers are required to match a numbered list of items from the listening text to a set of options on the question paper. The set of options may be criteria of some kind. Task 3 Test takers are required to complete labels on a plan (eg of a building), map (eg of part of a town) or diagram (e.g. of a piece of equipment). The answers are usually selected from a list on the question paper. Task 4 Test takers are required to fill in the gaps in an outline of part or of all of the listening text. The outline will focus on the main ideas/facts in the text. It may be: 1. a form: often used to record factual details such as names 2. a set of notes: used to summarise any type of information using the layout to show how different items relate to one another 3. a table: used as a way of summarising information which relates to clear categories – e.g. place/time/price, 4. a flow-chart: used to summarise a process which has clear stages, with the direction of the process shown by arrows. Test takers may have to select their answers from a list on the question paper or identify the missing words from the recording, keeping to the word limit stated in the instructions. Test takers do not have to change the words from the recording in any way. Test takers should read the instructions very carefully as the number of words or numbers they should use to fill the gaps will vary. A word limit is given, for example, ‘NO MORE THAN TWO WORDS AND/OR A NUMBER’. Test takers are penalised for writing more than the stated number of words, and test takers should check this word limit carefully for each task. Contracted words will not be tested. Hyphenated words count as single words. Task 5 Test takers are required to read a set of sentences summarising key information from all the listening text or from one part of it. They then fill a gap in each sentence using information from the listening text. A word limit is given, for example, ‘NO MORE THAN ONE WORD AND/OR A NUMBER’. Test takers are penalised for writing more than the stated number of words. (Test takers should check this word limit carefully for each task: the limit is either ONE, TWO or THREE words). Contracted words will not be tested. Hyphenated words count as single words. Task 6 Test takers are required to read a question and then write a short answer using information from the listening text. A word limit is given, for example, ‘NO MORE THAN THREE WORDS AND/OR A NUMBER’. Test takers are penalised for writing more than the stated number of words. (Test takers should check this word limit carefully for each task.) Contracted words will not be tested. Hyphenated words count as single words. Sometimes test takers are given a question which asks them to list two or three points.

2. Writing

Task 1 In Writing Task 1, test takers may be asked to describe facts or figures presented in one or more graphs, charts or tables on a related topic; or they may be given a diagram of a machine, a device or a process and asked to explain how it works. They should write in an academic or semi-formal/neutral styles and include the most important and the most relevant points in the diagram. Some minor points or details may be left out. Test takers should spend no more than 20 minutes on this task. They are asked to write at least 150 words and will be penalised if their answer is too short. While test takers will not be penalised for writing more than 150 words, they should remember that a longer Task 1 answer may mean that they have less time to spend on Task 2, which contributes twice as much to the Writing band score. Test takers should also note that they will be penalised for irrelevance if the response is off-topic or is not written as full, connected text (e.g. using bullet points in any part of the response, or note form, etc.). They will be severely penalised for plagiarism (i.e. copying from another source). Number of Questions: 1 Task 2 In Writing Task 2, test takers are given a topic to write about an academic or semi-formal/neutral style. Answers should be a discursive consideration of the relevant issues. Test takers should make sure that they read the task carefully and provide a full and relevant response. For example, if the topic is a particular aspect of computers, they should focus on this aspect in their response. They should not simply write about computers in general. Test takers should spend no more than 40 minutes on this task. They are asked to write at least 250 words and will be penalised if their answer is too short. While test takers will not be penalised for writing more than 250 words, if they write a very long answer they may not have time for checking and correcting at the end and some ideas may not be directly relevant to the question. Task 2 contributes twice as much to the final Writing band score as Task 1. Therefore, test takers who fail to attempt to answer this task will greatly reduce their chance of achieving a good band. Test takers will be penalised for irrelevance if the response is off-topic or is not written as full, connected text (e.g. using bullet points in any part of the response, or note form, etc.). They will be severely penalised for plagiarism (i.e. copying from another source). Finally, test takers should make sure that they do not copy directly from the question paper because this will not be assessed. Number of Questions: 1 3. Reading Three reading passages with a variety of questions using a number of task types. Task 1 : Multiple choice Test takers are required to choose the best answer from four alternatives (A, B, C or D), or the best two answers from five alternatives (A, B, C, D or E), or the best three answers from seven alternatives (A, B, C, D, E, F or G). Test takers write the letter of the answer they have chosen on the answer sheet. The questions may involve completing a sentence, where they are given the first part of a sentence and then choose the best way to complete it from the options, or could involve complete questions; with the test takers choosing the option which best answers them. The questions are in the same order as the information in the text: that is, the answer to the first question in this group will be located in the text before the answer to the second question, and so on. This task type may be used with any type of text. Task 2 : Identifying information Test takers will be given a number of statements and asked: ‘Do the following statements agree with the information in the text?’ They are then required to write ‘true’, ‘false’ or ‘not given’ in the boxes on their answer sheets. It is important to understand the difference between ‘false’ and ‘not given’. ‘False’ means that the passage states the opposite of the statement in question; ‘not given’ means that the statement is neither confirmed nor contradicted by the information in the passage. Students need to understand that any knowledge they bring with them from outside the passage should not play a part when deciding on their answers. Task 3: Identifying writer’s views/claims Test takers will be given a number of statements and asked: ‘Do the following statements agree with the views/claims of the writer?’ They are required to write ‘yes’, ‘no’ or ‘not given’ in the boxes on their answer sheet. It is important to understand the difference between ‘no’ and ‘not given’. ‘No’ means that the views or claims of the writer explicitly disagree with the statement, i.e. the writer somewhere expresses the view or makes a claim which is opposite to the one given in the question; ‘not given’ means that the view or claim is neither confirmed nor contradicted. Students need to understand that any knowledge they bring with them from outside the passage should not play a part when deciding on their answers. Task 4: Matching information Test takers are required to locate specific information within the lettered paragraphs/sections of a text, and to write the letters of the correct paragraphs/sections in the boxes on their answer sheet. They may be asked to find: specific details, an example, a reason, a description, a comparison, a summary, an explanation. They will not necessarily need to find information in every paragraph/section of the text, but there may be more than one piece of information that test takers need to locate in a given paragraph/section. When this is the case, they will be told that they can use any letter more than once. This type of task can be used with any text as it tests a wide range of reading skills, from locating detail to recognising a summary or definition. Task 5: Matching headings Test takers are given a list of headings, usually identified with lower-case Roman numerals (i, ii, iii, etc,). A heading will refer to the main idea of the paragraph or section of the text. Test takers must match the heading to the correct paragraphs or sections, which are marked alphabetically. Test takers write the appropriate Roman numerals in the boxes on their answer sheets. There will always be more headings than there are paragraphs or sections, so that some headings will not be used. It is also possible that some paragraphs or sections may not be included in the task. One or more paragraphs or sections may already be matched with a heading as an example for test takers. This task type is used with texts that contain paragraphs or sections with clearly defined themes. Task 6: Matching features Test takers are required to match a set of statements or pieces of information to a list of options. The options are a group of features from the text, and are identified by letters. Test takers may, for example, be required to match different research findings to a list of researchers, or characteristics to age groups, events to historical periods, etc. It is possible that some options will not be used, and that others may be used more than once. The instructions will inform test takers if options may be used more than once. Task 7: Matching sentence endings Test takers are given the first half of a sentence based on the text and asked to choose the best way to complete it from a list of possible options. They will have more options to choose from than there are questions. Test takers must write the letter they have chosen on the answer sheet. The questions are in the same order as the information in the passage: that is, the answer to the first question in this group will be found before the answer to the second question, and so on. This task type may be used with any type of text. Task 8: Sentence completion Test takers complete sentences in a given number of words taken from the text. They must write their answers on the answer sheet. The instructions will make it clear how many words/numbers test takers should use in their answers, e.g. ‘NO MORE THAN THREE WORDS AND/OR A NUMBER from the passage’, ‘ONE WORD ONLY’ or ‘NO MORE THAN TWO WORDS’. If test takers write more than the number of words asked for, they will lose the mark. Numbers can be written using figures or words. Contracted words will not be tested. Hyphenated words count as single words. The questions are in the same order as the information in the passage: that is, the answer to the first question in this group will be found before the answer to the second question, and so on. This task type may be used with any type of text. Task 9: Summary, note, table, flow-chart completion Test takers are given a summary of a section of the text, and are required to complete it with information drawn from the text. The summary will usually be of only one part of the passage rather than the whole. The given information may be in the form of: several connected sentences of text (referred to as a summary), several notes (referred to as notes), a table with some of its cells empty or partially empty (referred to as a table), a series of boxes or steps linked by arrows to show a sequence of events, with some of the boxes or steps empty or partially empty (referred to as a flow-chart). The answers will not necessarily occur in the same order as in the text. However, they will usually come from one section rather than the entire text. There are two variations of this task type. Test takers may be asked either to select words from the text or to select from a list of answers. Where words have to be selected from the passage, the instructions will make it clear how many words/numbers test takers should use in their answers, e.g. ‘NO MORE THAN THREE WORDS AND/OR A NUMBER from the passage’, ‘ONE WORD ONLY’ or ‘NO MORE THAN TWO WORDS’. If test takers write more than the number of words asked for, they will lose the mark. Numbers can be written using figures or words. Contracted words are not tested. Hyphenated words count as single words. Where a list of answers is provided, they most frequently consist of a single word. Because this task type often relates to precise factual information, it is often used with descriptive texts. Task 10: Diagram label completion Test takers are required to complete labels on a diagram, which relates to a description contained in the text. The instructions will make it clear how many words/numbers test takers should use in their answers, e.g. ‘NO MORE THAN THREE WORDS AND/OR A NUMBER from the passage’, ‘ONE WORD ONLY’ or ‘NO MORE THAN TWO WORDS’. If test takers write more than the number of words asked for, they will lose the mark. Numbers can be written using figures or words. Contracted words will not be tested. Hyphenated words count as single words. The answers do not necessarily occur in order in the passage. However, they will usually come from one section rather than the entire text. The diagram may be of some type of machine, or of parts of a building or of any other element that can be represented pictorially. This task type is often used with texts describing processes or with descriptive texts. Task 11: Short-answer questions Test takers answer questions, which usually relate to factual information about details in the text. This is most likely to be used with a text that contains a lot of factual information and detail. Test takers must write their answers in words or numbers on the answer sheet. Test takers must write their answers using words from the text. The instructions will make it clear how many words/numbers test takers should use in their answers, e.g. ‘NO MORE THAN THREE WORDS AND/OR A NUMBER from the passage’, ‘ONE WORD ONLY’ or ‘NO MORE THAN TWO WORDS’. If test takers write more than the number of words asked for, they will lose the mark. Numbers can be written using figures or words. Contracted words are not tested. Hyphenated words count as single words. The questions are in the same order as the information in the text.  

What is Geomorphology? | Geography Notes

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What is Geomorphology? The word geomorphology derives from three Greek words: gew (the Earth), morfh (form), and logo~ (discourse). Geomorphology is therefore ‘a discourse on Earth forms’. The term was coined sometime in the 1870s and 1880s to describe the morphology of the Earth’s surface , was originally defined as ‘the genetic study of topographic forms’ and was used in popular parlance by 1896. Today, geomorphology is the study of Earth’s physical land-surface features, its land forms – rivers, hills, plains, beaches, sand dunes, and myriad others. Some also include the submarine landfors and other terrestrial type planets and satellites in the solar system. Geomorphology investigates landforms and the processes that fashion them. Form, process, and the interrelationships between them are central to understanding the origin and develop – ment of landforms. In geomorphology, form or morphology has three facets –
  • constitution (chemical and physical properties described by material property variables),
  • configuration (size and form described by geometry variables),
  • and mass flow (rates of flow described by such massflow variables as discharge, precipitation rate, and evaporation rate)
Origin of Geomorphology Ancient Greek and Roman philosophers wondered how mountains and other surface features in the natural landscape had formed. Aristotle, Herodotus, Seneca, Strabo, Xenophanes, and many others discoursed on topics such as the origin of river valleys and deltas, and the presence of seashells in mountains. Xenophanes of Colophon (c. 580–480 BC) speculated that, as seashells are found on the tops of mountains, the surface of the Earth must have risen and fallen. Herodotus (c. 484–420) thought that the lower part of Egypt was a former marine bay, reputedly saying ‘Egypt is the gift of the river’, referring to the year-by-year accumulation of river-borne silt in the Nile delta region. Aristotle (384–322 BC) conjectured that land and sea change places, with areas that are now dry land once being sea and areas that are now sea once being dry land. Strabo (64/63 BC–AD 23?) observed that the land rises and falls, and suggested that the size of a river delta depends on the nature of its catchment, the largest deltas being found where the catchment areas are large and the surface rocks within it are weak. Lucius Annaeus Seneca (4 BC–AD 65) appears to have appreciated that rivers possess the power to erode their valleys. About a millennium later, the illustrious Arab scholar ibn-Sina, also known as Avicenna (980–1037), who translated Aristotle, propounded the view that some mountains are produced by differential erosion, running water and wind hollowing out softer rocks. During the Renaissance, many scholars debated Earth history. Leonardo da Vinci (1452–1519) believed that changes in the levels of land and sea explained the presence of fossil marine shells in mountains. He also opined that valleys were cut by streams and that streams carried material from one place and deposited it elsewhere. In the eighteenth century, Giovanni Targioni-Tozzetti (1712–84) recognized evidence of stream erosion. He argued that rivers and floods resulting from the bursting of barrier lakes excavated the valleys of the Arno, Val di Chaina, and Ombrosa in Italy, and suggested that the irregular courses of streams relate to the differences in the rocks in which they cut, a process now called differential erosion. Jean-Étienne Guettard (1715–86) argued that streams destroy mountains and the sediment produced in the process builds floodplains before being carried to the sea. He also pointed to the efficacy of marine erosion, noting the rapid destruction of chalk cliffs in northern France by the sea, and the fact that the mountains of the Auvergne were extinct volcanoes. Horace-Bénédict de Saussure (1740–99) contended that valleys were produced by the streams that flow within them, and that glaciers may erode rocks. From these early ideas on the origin of landforms arose modern geomorphology.

Best Books for SBI PO exam 2017

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Best Books for SBI PO exam 2017
We will give you an idea about the SBI paper pattern and how to ace each section with best books for SBI PO Exam 2017 available in the market.  As one would expect, due to a combination of lucrative salary, attractive perks, and job stability, competition to gain entry in the banking sector is increasing rapidly. And for jobs in this sector, State Bank of India (SBI) is one of the most sought after bank in India. SBI conducts exams for the recruitment of Probationary Officers (PO) every year. Around 15 to 20 lakhs aspirants take this exam against 2000 posts. Therefore, the cut-offs are very high and the exam is considerably difficult as compared to other banking exams. This year, SBI has advertised 2313 Probationary Officer posts. Candidates had to apply online from 07-02-2017 to 06-03-2017.

SBI PO Exam Pattern

The SBI PO selection procedure includes three phases:
  1. In Phase I (preliminary exam), there will be an objective based online paper of 1 hour. This will include the following sections.
  • English Language — 30 Questions — 30 marks
  • Quantitative Aptitude — 35 Questions — 35 marks
  • Reasoning Ability — 35 Questions — 35 marks
  1. Phase II (main exam) will consist of two tests, an objective test for 200 marks and a descriptive test. Both in online mode. The descriptive test will be administered immediately after completion of the objective test. A. Objective Paper – Questions from the following Sections will be asked in the Objective Test which will be of 3-hour.
Sr. No. Name of test No. of Questions Marks Duration (in Minutes)
1 Reasoning and Computer Aptitude 45 60 60
2 Data Analysis and Interpretation 35 60 45
3 English 35 40 40
3 General / Economy / Banking Awareness 40 40 35
Total 155 200 3 hours
     B. Descriptive Paper  
  • The Descriptive Test will be of 30 minutes duration comprising of 50 marks.
  • The test will be of English Language (Letter Writing and Essay).
  • The candidates are required to qualify in the Descriptive Test by securing passing marks.
  • Descriptive Test paper of only those candidates will be evaluated who have scored qualifying marks in the Objective Tests and are placed adequately high as per total marks in Objective Test.
Negative Marking-  For each wrong answer, one fourth of the marks assigned to that question will be deducted as penalty. 3. Phase III- Group Discussion and Personal Interview The Group Discussion will carry 20 marks and Interview will carry 30 marks. Candidates who qualify the main examination will be called for GD & PI according to their ranks.

Books For SBI PO Exam 2017

To excel in any competitive exam, one needs a smart plan, good study material, focused hard work, and perseverance. I have compiled for you a list of the best books that can be used for the preparation of Part A and B of SBI PO Exam 2017. Section-wise preparation If you feel you are not fully prepared in a certain section, I would suggest you pick up a book for that section. First get your concepts right and understand the solved examples. Once you have understood the approach to these questions then you can try to learn the shortcuts as well. After you are well-versed with that section, go for model practice papers. I have prepared a comprehensive list of SBI PO books for each section and hope you will find them useful in your preparation. Also, I have included links for both English and Hindi medium books.

Books For Quantitative Aptitude For SBI PO Exam 2017 

For English medium candidates
Quantitative Aptitude by R.S. Agarwal Buy on Amazon Buy on Flipkart
Quicker Mathematics by M. Tyra Buy on Amazon Buy on Flipkart
Arihant’s Fast Track Objective Arithmetic Buy on Amazon Buy on Flipkart
Advance Maths for General Competitions by KD Publications Buy on Amazon Buy on Flipkart
For Hindi medium candidates
Quantitative Aptitude by R.S. Agarwal Buy on Amazon Buy on Flipkart
Quicker Mathematics by M. Tyra Buy on Amazon Buy on Flipkart
Arihant’s Fast Track Objective Arithmetic Buy on Amazon Buy on Flipkart

SBI PO Books For English Section

English Grammar by Wren and Martin Buy on Amazon Buy on Flipkart
Essential English Grammar by Raymond Murphy Buy on Amazon Buy on Flipkart
Word Power Made Easy by Norman Lewis Buy on Amazon Buy on Flipkart
Objective General English by S P Bakshi Buy on Amazon Buy on Flipkart
Quick learning Objective General English by RS Aggarwal &  Vikas Aggarwal Buy on Amazon Buy on Flipkart

SBI PO Books For General Intelligence & Reasoning Section

For candidates preparing SBI PO Exam 2017 in English medium.
Verbal and Non-Verbal Reasoning by R S Aggarwal Buy on Amazon Buy on Flipkart
Analytical Reasoning by M K Pandey Buy on Amazon Buy on Flipkart
A New Approach to Reasoning Verbal and Non-Verbal by B S Sijwali, Indu Sijwal Buy on Amazon Buy on Flipkart
Logical and Analytical Reasoning (English) by A.K Gupta Buy on Amazon Buy on Flipkart
Quick learning Objective General English by RS Aggarwal &  Vikas Aggarwal Buy on Amazon Buy on Flipkart
For Hindi medium aspirants, here is the book list for SBI  PO Reasoning
Master Reasoning Book Verbal, Non-Verbal & Analytical by Arihant Publications Buy on Amazon Buy on Flipkart
Reasoning Test: Verbal & Non-Verbal by RPH Editorial Board Buy on Amazon Buy on Flipkart
Tricky Approach To Competitive Reasoning Verbal & Non-Verbal (Fully Solved) by Kiran Publications Buy on Amazon Buy on Flipkart

SBI PO Books For General Awareness

These are the book in English for candidates giving their SBI PO 2017 exam in English medium.
Manorama Year Book 2017 Buy on Amazon Buy on Flipkart
Current Affairs Yearly 2017 by Arihant Publications Buy on Amazon Buy on Flipkart
India 2017 Buy on Amazon Buy on Flipkart
For aspirants giving their SBI PO Exam 2017 in Hindi 
Manorama Year Book 2017 Buy on Amazon Buy on Flipkart
Current Affairs Varshiki 2017 by Arihant Publications Buy on Amazon Buy on Flipkart
Bharat 2017 Buy on Amazon Buy on Flipkart

SBI PO Books For Marketing

For English Medium Candidates 
Marketing Aptitude (English) by Arihant Experts Buy on Amazon Buy on Flipkart
Marketing Aptitude/Knowledge For SBI PO & SBI Clerk And Other Banks & Insurance Exams by Kiran Prakashan Buy on Amazon Buy on Flipkart
For Hindi Medium Candidates 
Marketing Aptitude by RPH Editorial Buy on Amazon Buy on Flipkart
Marketing Aptitude/Knowledge For SBI PO & SBI Clerk And Other Banks & Insurance Exams by Kiran Prakashan Buy on Amazon Buy on Flipkart

SBI PO Books For Computer Awareness

For English Medium Candidates 

Objective Computer Awareness For General Competitive Exams: Arihant Publications Buy on Amazon Buy on Flipkart
Objective Computer Knowledge & Literacy: Kiran Prakashan Buy on Amazon Buy on Flipkart
For Hindi Medium Candidates 
Objective Computer Awareness by RPH Editorial Board Buy on Amazon Buy on Flipkart
Objective Computer Knowledge & Literacy: Kiran Prakashan Buy on Amazon Buy on Flipkart

SBI PO Previous year papers/ Model papers

Once you are done revising the syllabus of each section, it is important to practice previous years paper and mock papers to improve your speed and have an idea about the type of questions asked in the exams. After reviewing a lot of books, I have selected the following three books for practice. You need not buy all three! Just get any one.
 
30 Practice Sets for SBI PO Phase-1 2017 by Arihant Publications Buy on Amazon Buy on Flipkart
SBI: Probationary Officers-Previous Years Papers (Solved) by RPH Editorials Buy on Amazon Buy on Flipkart (Sold out)
SBI PO Phase – 1 Preliminary Exam Superfast Practice Sets by Kiran Publications Buy on Amazon Buy on Flipkart

SBI PO Descriptive Paper Books (English)

As I told you earlier, in the descriptive paper you will be judged on your knowledge of English through letter writing and essay writing. Any one of the following books would be sufficient if you need help with this section.
State Bank Of India & State Bank Associates PO  Exam – Descriptive English – Including Solved Papers Of 2010- 2014 by Kiran Prakashan  Buy on Amazon Buy on Flipkart
Descriptive General English by S.P. Bakshi  and Richa Sharma Buy on Amazon Buy on Flipkart
Descriptive English & Communication Skills by K. Kundan – Buy on Flipkart

Books For Preparation of SBI Interview

Guide To Bank Interviews by M.B.Sivaramakrishnan – Buy on Flipkart

Conclusion

Hope this list of books for SBI will help you in better preparation for the SBI PO Exam 2017. Feel free to use the comments section below for any questions, comments or suggestions you may have.

Best Books for SSC CGL Exam – Complete books list

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Best Books for SSC CGL Exam – Complete books list
In this post we will discuss books for SSC CGL Tier 1, if you came here looking for Tier 2 details – go to this link. Also, before reading this post, I hope you are aware of the basic SSC CGL notification details. Here we will discuss the important or Best books for SSC CGL Exam. Don’t Waste your time on internet free things Just buy these books and Start practice bcz only practice make you to score higher in the exam. A large number of candidates are preparing very diligently for it. You may be talented. But without hard work, you will go nowhere.

SSC CGL Paper Pattern

It is better to actually read and practice a few good books than to download several and read none. I take it that the only reason you are continuing to read this post is because you really want to know about SSC CGL Tier 1 books! But before you buy books, it is important that you know about the SSC CGL Exam syllabus and the SSC CGL exam paper pattern. In case you know it, very good. Otherwise, just go through those links. Let us proceed now. I’ll take you through a brief summary of SSC CGL books suggestions, and them we will look at the books section wise.

Safest SSC CGL Books — If You Are Confused

If you are really in a hurry and can’t read the whole post, I am providing a summary of the best books in one place. You can not go wrong with these books. But if you can read the sections, you will find a good comparison of multiple books. At the time of writing this post, Amazon had the best deals (zero shipping charges on a number of popular books). So be sure to compare the prices on Amazon and Flipkart before you order. I have provided links for both wherever available.
Section Books Flipkart  Amazon 
Math/Quant Arihant’s Fast Track Objective Arithmetic Buy Buy
English Objective General English by S P Bakshi (Arihant) Buy Buy
Reasoning Analytical Reasoning by M K Pandey Buy Buy
General Awareness Manorama Yearbook 2016 (English) Buy Buy
Previous Years Solved Papers Arihant’s SSC CGL Solved Papers (2010-2015) Buy Buy

Books for SSC CGL Quantitative aptitude section

  Math is not very easy as well as not a very tough task. If you practice a lot then it is easier than anything else. So, forget everything just practice.

What’s Your Level Book Recommended Flipkart Amazon
Superb fundas and need little practice NCERT books Download NCERT books from the links above
Okay fundas and need to practice Quantitative Aptitude for Competitive Examinations (R S Aggarwal) OR Buy Buy
Arihant’s Fast Track Objective Arithmetic Buy Buy
Need help with fundas Magical Book On Quicker Maths Buy Buy

Quantitative Aptitude Bonus Section — What To Study & From Where

We have also compiled this fantastic table for you which has details on how to study. NOTE: Use the NCERT book (link above) and the book you decided to buy. I have only written R S Aggarwal because more people use it. In case you are buying Arihant, use it wherever I have suggested Aggarwal.
Chapter Topics Books To Refer
Number System
  • Divisibility
  • LCM and HCF
  • Fractions & Decimal fractions
  • NCERT Class 7 Chapter 2, 9
  • NCERT Class 10 Chapter 1
  • M.Tyra Chapter 4,7,8, 9 and 12
Basic Mathematics
  • BODMAS
  • NCERT Class 8 Chapter 1
  • Surds and indices
  • NCERT Class 8 Chapter 12
  • NCERT Class 9 Chapter 1
  • M.Tyra Chapter 11
  • Square & Cube Root
  • NCERT Class 8 Chap 6 and 7
  • M.Tyra Chapter 5 & 6
Algebra
  • Linear equation
  • Graphs of Linear Equations
 
  • NCERT Class 8 Chap 2 and 9.
  • NCERT Class 9 Chap 4
  • NCERT Class 10 Chap 3
  • Quadratic equations
  • Polynomials
  • Basic algebraic identities
  • NCERT Class 8 Chap 14
  • NCERT Class 9 Chap 2
  • NCERT Class 10 Chap 4
Average, Ratio & Proportion
  • Alligation
  • M.Tyra Chapter 24
  • Quantitative Aptitude by R.S Aggarwal Chapter 20
  • Average
  • M.Tyra Chapter 19
  • Ratio & proportion
  • NCERT Class 8 Chap 13
  • M.Tyra Chapter 16
  • Partnership
  • M.Tyra Chapter 17
Percentage
  •  Percentage
  • NCERT Class 8 Chap 8
  • M.Tyra Chapter 18
Time & Distance
  • Time, speed & distance
  • Problems on trains
  • Boat & streams
  • Time, Work and Wages
  • Pipes and Cisterns
  • M.Tyra Chapter 25 to 30
  • Quantitative Aptitude by R.S Aggarwal Chapter 15 to 19
Profit & Loss & Interest
  • Profit & Loss
  • Simple Interest & Compound Interest
  • Discount
  • M.Tyra Chapter 21 to 24
Geometry
  • Triangle and its centres
  • Congruence and similarity of triangles
  • Circle and its chords
  • Tangents & angles subtended by chords of a circle
  • Common tangents to two or more circles
  • NCERT Class 9 Chapter 6, 7, 8 and 10.
  • Mensuration (Area and Volume)
  • NCERT Class 8 Chap 3 & 11.
  • NCERT Class 9 Chap 9, 12, 13.
  • NCERT Class 10 Chapter 13
  • M.Tyra Chapter 31& 32
  • Trigonometry – Trignometric ratios, Degree and Radian Measures, Standard Identities, Complementary angles, Heights and Distances
  • NCERT Class 10 Chapter 8 and 9
  • Quantitative Aptitude book
  • M.Tyra Chapter 36
Data interpretation
  • Data sufficiency & analysis
  • Histogram, Frequency polygon, Bar diagram & Pie chart
  • M.Tyra Chapter 34 & 35
  • Quantitative Aptitude by R.S Aggarwal Chapter 36-39
Miscellaneous
  • Progression (AP + GP)
  • NCERT Class 10 Chapter 5
  • Series
  • M.Tyra Chapter 33

Books For SSC CGL English Section

English section is quite easy, and should not take a lot of time to prepare. In the post linked above (the one I asked you to read), we have given a detailed breakup of the expected questions for English, as well as other sections. If your English is mediocre, just practice using the solved previous years question papers. If, however, you think that you need more focused practice, let me recommend you some books.

English Books For Exam Pattern Questions Practice

There are two good exam-oriented English books which adequately cover different types of questions. Choose any one and you are good to go — Objective General English by S P Bakshi (Arihant) OR Quick learning Objective General English by RS Aggarwal &  Vikas Aggarwal. Apart from these, there is another book which has great reviews — Objective English for Competitive Examinations by Hari Mohan Prasad, but I have not had a chance to try it. Are you confused, about which English book to choose? Well, I think all the three would be of a similar level. To be honest, if your basics are clear, all you need is practice. So choose anyone which is most recently updated and is also within your budget.
Book Flipkart Amazon
Objective General English by S P Bakshi (Arihant) Buy Buy
Quick learning Objective General English by RS Aggarwal & Vikas Aggarwal Buy Buy
Objective English for Competitive Examinations Buy Buy

Do You Also Need To Revise Grammar?

In case you need to work on your basics, then you HAVE to revise English grammar. There is no other option. And to revise grammar, there has never been a book better than Wren And Martin (it has remained the top seller in multiple categories on Amazon for as long as I can remember). The book is available in two editions – one has colorful illustrations the other one is the regular black and white. High School English Grammar and Composition by Wren and Martin – Buy on Flipkart (Old Version) or Buy on Amazon (New Version). For some weird reason, at the time of writing this post, Flipkart is only selling the new version in a pack of 3.

Need To Build Your Vocabulary?

Check out Word Power Made Easy on Amazon or Flipkart. Not much to say – nothing compares to this one!

Books For SSC CGL Tier 1 General Intelligence & Reasoning Section

There are two important factors which will decide how fast and accurately you can solve reasoning problems — a logical thought process, and exposure to different types of problems. If you are naturally good in mathematics, chances are high that you will do great with reasoning as well. Practice, as you will learn, is very important. Your brain’s capacity to solve reasoning questions increases exponentially when you try to solve different types of questions. R S Aggarwal is the highest selling book. It is a good choice if you don’t need a lot of explanations and are mainly looking for practice questions. If you need more explanations, I suggest you go with M K Pandey. Another book with rave reviews is Sijwali & Sijwali, available from Arihant Publishers.
Book Flipkart Amazon
Analytical Reasoning by M K Pandey Buy Buy
Verbal and Nonverbal Reasoning by R S Aggarwal Buy (NEW) Buy (OLD)
New Approach to Reasoning Verbal, Non-Verbal & Analytical by B S Sijwali, Indu Sijwali Buy Buy

Books Available For General Awareness

General awareness (more commonly called as General Knowledge or GK) is not something you can expect to master in a day. But from an exam point of view, if you spend time consistently, you will reach a good level in a month or so. But it is very important that you base your preparations around a good book. Otherwise, you will be wasting time here and there collecting a list of this, and an article on that.

Time-Saving Tip

Most aspirants are confused when it comes to preparing for the General Awareness section. They spend waste their time either for memorizing stupid lists or for collecting them. So we have put together an exhaustive post to prepare for SSC CGL General Awareness Section.
Among the options available here, nothing comes close to Manorama Yearbook. It is THE best book to prepare for GK section in competitive exams. Check out our detailed review of the book. If you are allergic to Manorama, then you can try Lucent’s GK Book.
Book Flipkart Amazon
Manorama Yearbook 2016 (English) Buy Buy
Manorama Yearbook 2016 (Hindi) Buy Buy
Lucent’s General Knowledge 2015 (English) Buy Buy
Lucent’s General Knowledge (Hindi) Buy (2013) Buy (2015)
IMPORTANT NOTE: Before buying GK book, carefully check the year of publication. And I don’t mean the year published in the name! For marketing purpose, publishers sell books with next years name in the current year. For example, a book may have its name as “General Knowledge 2016” even though it was published in 2015! . So look for the actual ‘year of publication’. Newpapers these days are not worth the paper they are printed on. So even though many people would advise you to read papers (even I have done in my several articles, but I’ll remove those when I get a chance to update those articles), it’s better that you use your time more efficiently elsewhere.

What About SSC CGL Solved And Practice Test Papers

CAUTION: Solved-papers books tend to have some errors and mistakes, higher as compared to sectional books. But people don’t complain because of the price at which these things sell. Just keep this at the back of your mind. If you are not buying ANY of the books above, you have to buy, study and thoroughly practice through solved papers. Questions that are asked in SSC CGL repeat from year to year – just like many other exams. So by practicing solved papers you will prepare yourself for exactly the type of questions which are asked in the exams. Kiran’s SSC CGL combined Graduate Level Exams Question Bank 1999-2014 (45 solved papers of previous year exams) is undoubtedly the best book for solved papers –  Best Deal On Amazon. However at the time of writing, the most updated book for solved papers is Arihant’s Solved Papers (upto 2015) – only available on Amazon. It cover’s 17 solved papers covering 2010-2015. Solved papers are available in two flavors – full length solved papers and solved questions from previous years papers which are categorized chapter wise. Which one you should use will depend on when you plan to solve previous years questions. Some people like to study all the sections individually and then they start practicing full-length previous years papers. The other kind of people, read the fundas of a chapter in a section, for eg. Algebra in Quantitative aptitude, and then they practice solving previous years questions from this topic. I would personally prefer the second method. But what really matters is that you actually practice solving previous years questions.

Full-Length SSC CGL Previous Years Solved Papers 

Arihant and Kiran, both provide a large number of solved papers. These are full length papers organized year wise.
Book Flipkart Amazon
Solved Papers SSC CGL Combined Graduate Level Pre Examination Tier-I by Arihant (2010-2015) – Buy
Kiran’s SSC CGL combined Graduate Level Exams Question Bank 1999-2014 Buy Buy
SSC CGL 50 Practice Papers Combined Graduate Level Tier-I Examination Buy Buy

SSC CGL Solved Papers – Organized section-wise

As I said earlier, some people (including me) prefer that previous years papers are arranged section wise – topic wise. Especially if your fundas are good, you are comfortable with the syllabus and you feel that all you need is practice – it makes sense to choose the books listed below. Of course, if you want solved questions from all the sections better stick to the options above (single book to buy).
Section Covered (Previous years solved questions arranged topic-wise) Book Flipkart Amazon
Only Quantitative Aptitude SSC Mathematics Chapterwise Solved Papers 1999 – Till Date by Kiran Prakashan – Buy
Only English Section SSC English Language Chapterwise Solved Papers 1997-Till Date by Kiran Prakashan Buy  Buy
Only General Awareness SSC General Awareness Chapterwise Solved Papers 1997 – Till Date by Kiran Prakashan Buy  Buy 
Only General Intelligence & Reasoning SSC Reasoning Chapterwise Solved Papers 1999 – Till Date by Kiran Prakashan Buy  Buy 

What Not To Do

If you want to know what to do, it is equally important to know what not to do. Even though I am suggesting you to buy books, I want to explicitly caution you to not buy “all in one” type of books (apart from solved papers). The problem with these all in ones is that they don’t cover the subject material properly. On the other hand, section/subject books will come handy for multiple exams. And you can pass them to your juniors, or keep them with you later reference. The other thing which you should not do is buy too many books and not study them at all. Be realistic.

Klosneuviruses (Giant Virus): Contradict the theory of virus as fourth domain of life alongside Bacteria, Eukaryotas and Archean

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Klosneuviruses (Giant Virus): Contradict the theory of virus as fourth domain of life alongside Bacteria, Eukaryotas and Archean

Klosneuviruses (Giant Virus): Contradict the theory of virus as fourth domain of life alongside Bacteria, Eukaryotas and Archean

Fourth domain of life :- Evolutionary biologists have never known what to make of viruses, arguing over their origins for decades. But a newly discovered group of giant viruses, called Klosneuviruses, could be a ‘missing link’ that helps to settle the debate — or provoke even more discord. It is Mystery for biologists that what to make of viruses, it main debate topic for decades. Newly discovery of Giant Virus group also called Klosneuviruses, could be help to know more about this mystery and help to settle the debate. Mimiviruses, a giant viruses group found by the researchers in 2003, with genes that suggested their anscestors could live outside of a host cell. The discovery split researchers into two camps. One group thinks viruses started out as self-sufficient organisms that became trapped inside other cells, eventually becoming parasitic and jettisoning genes they no longer needed. Another group views viruses as particles that snatched genetic material from host organisms over hundreds of millions of years. Latter idea supported by the latest study published on 6 April 2017 in Science, that viruses are made up a patchwork of stolen parts. But it has already sparked controversy and is unlikely to settle the raucous debate. After the Mimivirus discovery, some researchers developed a theory that put viruses near the root of the evolutionary tree. They proposed that viruses comprised a ‘fourth domain’ alongside bacteria, eukaryotes — organisms whose cells contain internal structures such as nuclei — and bacteria-sized organisms called archaea.
Mimiviruses, which at 400 nanometres across are about half the width of an E. coli cell and can be seen under a microscope, were unique in that they contain DNA encoding the molecules that translate RNA messages into proteins. Normal viruses make their host cells produce proteins for them. The team that discovered Mimiviruses thought the virus’ ability to make their own proteins suggested that these viral giants descended from ancient free-living cell type that may no longer exist2. “They reinitiated the debate about the living nature of viruses, and of their relationship with the ‘cellular’ world,” says evolutionary biologist Jean-Michel Claverie of Aix-Marseille University in France, a co-author of the original Mimivirus paper.

Filling in the gaps

The question could be resolved by comparing genome sequences from viruses with those of their eukaryotic hosts. Mimiviruses contain too few eukaryotic-like genes to perform a statistical analysis that could determine their evolutionary relationships. The difficulty is compounded by the fact that viral genomes mutate very quickly. Klosneuviruses may fill this gap. Their genomes contain code for dozens of enzymes and other molecular machinery used in making proteins. Some of these parts have never been seen before in any virus, including Mimiviruses.
“They’re kind of this missing link we haven’t had before,” says study co-author Tanja Woyke, a microbiologist at the Joint Genome Institute in Walnut Creek, California.
Woyke and her colleagues discovered the Klosneuviruses by accident while studying how bacteria break down sewage at a treatment plant in Austria. They sequenced the genomes in their samples to identify the organisms present, and found four genomes similar to those of Mimiviruses. Using sophisticated software to trace the evolutionary history of their mystery genomes, the researchers found that the translation genes seemed to have been picked up one by one over hundreds of millions of years. This evidence supports the idea that viruses stole parts of their genomes, they say. It’s possible, however, that Mimiviruses and Klosneuviruses originated in different ways, making both ideas on viral origins possible, says Frederik Schulz, a bioinformatician at the Joint Genome Institute and a co-author on the new study.

Debating domains

It’s unclear which eukaryotic organisms donated their genes to the Klosneuvirus group. And because they haven’t identified the host, the researchers can’t grow the virus yet. The viruses do not seem to infect the same type of amoeba as Mimivirus and other known giant viruses. Claverie points out that the majority of the Klosneuviruses’ translation machinery does not match that of any other known organism. And he worries that the computational model used to infer the viruses’ ancestry could pick up leftover pieces of DNA in the sample, potentially contaminating the data. “I am waiting to see a real virus isolated with its host in a tube, before I would believe any of their evolutionary interpretations,” he says. David Moreira, an evolutionary biologist at the University of Paris South, doesn’t think that’s necessary. He says that plenty of evolutionary work can be done on a genome alone, and he is glad to see more papers coming to the conclusion that viruses are not a fourth domain of life. Mimivirus co-discover Didier Raoult, a microbiologist at Aix-Marseille University, says this latest discovery won’t settle the debate, but it’s a nice find nevertheless. “We’re finding a part of the world that has been completely ignored and need to be patient.”
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