# Learn Plant Science > Explore the the green world with us ## Posts - [R for Phylogenetic](https://learnplantscience.com/phylogenetic/r-for-phylogentic/): Contract the UPGMA tree Neighbor Joining tree Maximum Parsimony Tree & Maximum Likelihood Tree - [Character based approach of phylogenetic analysis](https://learnplantscience.com/phylogenetic/character-based-approach-of-phylogenetic-analysis/): These approaches simultaneously compare all sequences in the alignment, considering a one character (a site in the alignment) at a time to calculate the tree score Tree score is a quantitative measurement of the particular phylogenetic tree fits the observed data. The tree score of the Maximum parsimony (MP) – minimum numbers of changes required ... Read More "" » - [Distance based approach of phylogenetic analysis](https://learnplantscience.com/phylogenetic/analysis-methods-of-molecular-phylogenetic-data/): The distance between every pairs of sequences are calculated, resulting data matrix is used for tree reconstruction. Clustering procedure of the distance base analysis is given below. Calculate distances and produce the matrix between all combination of taxa. Join the two closest clusters. Recalculate the distances between all the clusters. Repeat the above procedure until ... Read More "" » - [Phylogenetic Analysis data](https://learnplantscience.com/phylogenetic/phylogenetic-analysis-data/): Taxa – The group of organisms, that are classified based on the evolutionary relationships. Characters – specific traits or features that can be used to distinguish between different taxa. The characters that used for building the phylogenetic trees Classical phylogenetic analysis uses morphological features – number of legs, anatomy Modern phylogenetic analysis uses molecular information ... Read More "" » - [Applications of the phylogenetic Analysis.](https://learnplantscience.com/phylogenetic/applications-of-the-phylogenetic-analysis/): Evolutionary medicine Using positive selection to identify the pathogenic mechanisms of HIV in human. Using the evolutionary analyzes to identify new disease out breaks. Learn about the origin of the diseases. Identify the diseases resistance mechanisms in other hosts to identify the better treatments. Population studies – population structure and the subdivisions. Studying mating systems ... Read More "" » - [Connecting the Dots in Evolution: An Introduction to Phylogenetic Analysis :](https://learnplantscience.com/phylogenetic/introduction-to-phylogenetic-analysis/): Phylogenetic analysis is the finding of the genetic relationships among organisms. Phylogeny is the study of an organism’s evolutionary history; it includes time (when), mode (how), and place (where). Systematic is the classification and studying the diversity of organisms based on their phylogenetic relationships. Modern phylogenetics is highly revolutionized by molecular data. All life on ... Read More "" » - [Environmental Impact Assessments (EIAs)](https://learnplantscience.com/environment-science/environmental-impact-assessments-eias/): Environmental Impact Assessments (EIA) is an internationally accepted transparent process to predict and identify potentially significant environmental impacts of development proposals and to suggest mitigation measures to minimize the negative impacts and maximize the positive impacts. large-scale development projects that are likely to have significant impacts on the environment are listed as EIA prescribed projects ... Read More "" » - [Cleaner Production](https://learnplantscience.com/environment-science/cleaner-production/): Definitions of terminologies Wastes – Resources at wrong place in wrong form Environmental Pollution – It is throwing away of part of resources, introduction of harmful substances or pollutants into the natural environment. Cleaner production – Continuous application of an integrated preventive environmental strategy to processes, products and services to increase efficiency and reduce the ... Read More "" » - [Climate Change](https://learnplantscience.com/environment-science/climate-change/): Weather Vs Climate Weather Climate short term changes in the atmospheric variables in a given area over a short period of time (hours/days) Average weather conditions of particular area long over period time (3 decades or more) Example for the climate changes – Glacial and interglacial periods, earth is currently at the interglacial phase but ... Read More "" » - [Ecological Footprint & Biocapacity](https://learnplantscience.com/environment-science/ecological-footprint-biocapacity/): Ecological footprint Ecological footprint is measurement of how much land, water, and other natural resources are required to produce the resource consumed and to adsorb the waste generated by given population or activity. Ecological footprint = Population x Consumption x Impact factor / Biocapacity Population – Number of individuals in the population. Consumption – Amount ... Read More "" » - [Natural Resources](https://learnplantscience.com/environment-science/natural-resources/): Resources is a source or supply from which benefit is produced. A natural resource is replaced by natural process. Renewable resources is a resources that capable of natural regeneration within a time span relevant to human e.g. – freshwater,soil, plant and animals,clean air. Non-renewable resources – available only in limited quantities or their rate of ... Read More "" » - [Population](https://learnplantscience.com/environment-science/population/): Population is the group of organisms of same species living in in the particular habitat. forces that controlling the growth of a population are biotic potential (ability to reproduce at given rate and inherent the characteristic of a populations), environmental resistance (opposite to the growth (limited resources, pest, predators). Limiting factors population growth will be ... Read More "" » - [Evolution](https://learnplantscience.com/environment-science/evolution/): Evolution is the natural process of irreversible changes producing new forms with adaptive improvements. Cosmological evolution Chemical evolution Biological evolution Cultural evolution Cosmological evolution Cosmological evolution is explained by the big bang theory. 13.8 billion years ago created all the matters in the universe. Initially only protons and the neutrons, later 99% helium and hydrogen ... Read More "" » - [Introduction to Environment science](https://learnplantscience.com/environment-science/introduction-to-environment-science/): The Environment science is branch of science concerned with relation between organisms and their environment. it is a applied science that gives understanding of the nature of the problem and the helps ways to seek the solutions. It is a multidisciplinary approach including biology, chemistry,geology, physics, etc. Ecological principles of the environmental science. 1. Every ... Read More "" » - [Vectors for Gene Cloning](https://learnplantscience.com/molecular-biology/vectors-for-gene-cloning/): Gene cloning is a process in which multiple copies of genetic material, such as genes, are created. To do this, scientists utilize vectors – specific strands of DNA that can be inserted into cells and transport the desired genes with them. Through gene cloning, researchers have been able to gain valuable insight into genetics and ... Read More "" » - [Manipulation of Purified DNA](https://learnplantscience.com/molecular-biology/manipulation-of-purified-dna/): Performing a restriction digest in the laboratory Digest a sample of λ DNA (concentration 125 μg ml−1) with HindIII DNA – The amount of DNA required for restriction digestion varies depending on the experiment and its desired results. – To digest 2 μg of λ DNA -16 μl of the DNA sample is needed Buffer ... Read More "" » - [Plasmid Vectors for plant cells](https://learnplantscience.com/molecular-biology/plasmid-vectors-for-plant-cells/): Ti-plasmid are widely utilized to introduce DNA into plant cells. but natural form of Ti plasmids are not suitable for as cloning vector because The size of the Ti plasmids is 150kb-200kb, it is extremely difficult to manipulation. Binary vector Consist a helper plasmid and a donor plasmid. Helper plasmid (binary cloning vector)contains disarmed Ti ... Read More "" » - [Recombinant DNA Technology](https://learnplantscience.com/molecular-biology/recombinant-dna-technology/): Recombinant DNA Technology is the process that isolation and manipulation of DNA sequences. it involves cutting, combining of DNA from different sources and create new DNA combination/genes. Gene Cloning Gene cloning is the process of generation of genetically identical copy of cell or an organism. A fragment of DNA, that gene of interest on cloning ... Read More "" » - [Hierarchical Cluster Analysis in R studio](https://learnplantscience.com/statistics-experimental-design-data-analysis-using-r/hierarchical-cluster-analysis-in-r-studio/): ############view first six rows of dataset############### Output: Output: - [Principal component analysis (PCA) in R studio](https://learnplantscience.com/statistics-experimental-design-data-analysis-using-r/principal-component-analysis-pca-in-r-studio/): Output: According to this petal length and petal width, sepal length and petal length , Sepal length, and petal width are highly correlated. This leads to multicollinearity. This issue can be reduce using PCA analysis. Now there is no correlation between multiple variables therefore there is no  multicollinearity issue. Output: BIPLOT is useful to understand what is ... Read More "" » - [Multivariate Analysis](https://learnplantscience.com/statistics-experimental-design-data-analysis-using-r/multivariate-analysis/): Multivariate analysis is a statistical methods that perform simultaneous analysis of multiple variables. identify the relationships among variables and identify the patterns and trends of the information. Types of multivariate analysis Factor Analysis Principal component analysis Cluster analysis Discriminant analysis Canonical correlation analysis. Factor Analysis Factor analysis is used to identify the factors or dimensions ... Read More "" » - [Fertilizers](https://learnplantscience.com/horticulture/fertilizers/): Primary aim of the fertilization is obtain the optimum yield from the crops. Fertilizers contains soil, organic matters, macro nutrient, micro nutrients. it has relatively low pH. Fertilizers are mainly three types Chemical Organic – natural or biological origin compost, crop residue, goat dung, cattle dung, green manure, leaf litter, rice husks Organic fertilizers advantages ... Read More "" » - [Soil treatments](https://learnplantscience.com/horticulture/soil-treatments/): There are many disease causing organisms are present in the soil. e.g – Insect, microorganisms, Nematodes, fungi, bacteria. therefore soil treatments are essential Mainly there are two treatments methods. Heat treatments Chemical treatments Heat treatment methods Electric current Microwaves Solar heat Heat treatment methods – Solar heat Beds must be prepared 3-10 weeks before the ... Read More "" » - [Container growth plants.](https://learnplantscience.com/horticulture/container-growth-plants/): Growth media mainly two types base on the amount of the media; field media that unrestricted the root growth, container growth plants roots are restricted to small volume of the growth medium. therefore these media must be ideal to obtain proper results. Potting media are mainly two parts Soil/loam less media Soil media Soil media ... Read More "" » - [Anthurium Cultivation.](https://learnplantscience.com/horticulture/anthurium-cultivation/): Anthuriums are flowering plants and belongs to family Araceae. inflorescence is cup shape and it consists of spathe and spadix. Anthurium are evergreen plants. flowering any time of the year. In the certain year anthurium can produce flowers in every leaf axial. Anthurium Cultivation – Media Can grown on various media charcoal, coco husk, leaf ... Read More "" » - [Breeding of asexual propagated crops](https://learnplantscience.com/plant-breeding/breeding-of-asexual-propagated-crops/): Breeding of asexual propagated crops are divided into four main groups. Flowerless or sterile Flowers but rarely set seed Normally seeds produce but propagated vegetatively Apomicts – reproduce asexually through the process of apomixis. Breeding methods of asexual propagated plants. Clone selection Hybridization and Clonal selection. Mutation breeding Clone selection Clones are always propagated and ... Read More "" » - [Seed Certification](https://learnplantscience.com/plant-breeding/seed-certification/): Seed certification is the process that ensure seeds that produce by plant breeders are having high quality, original genetic identity, highest genetic purity. All these qualities are retained as throughout a number of specific number of generations. Benefits of using certified seeds Development of seeds contains improved characters – herbicide tolerance, resistance to pests, improved ... Read More "" » - [Breeding of cross pollination crops](https://learnplantscience.com/plant-breeding/breeding-of-cross-pollination-crops/): Cross pollinated plants species have different gene pool structure and extent of genetic recombination. genes are shuffled every generation, in self pollinated crops variety developed as improved population. (inbred lines),in cross pollination plants are developed as hybrid varieties (HYB). There are two methods for breeding of cross pollinated plants. Selection methods – develop open pollination ... Read More "" » - [Marker Assisted Selection](https://learnplantscience.com/plant-breeding/marker-assisted-selection/): Plant breeding improves the genetic performance of the plants. Creation of the plant variety better than previous plants. Conventional breeding is based on the phenotype and marker assisted selection breeding is based on the genotype. Limitation of the conventional breeding Genotype is often interact with the environmental condition. phenotyping procedure is expensive and time consuming ... Read More "" » - [Post harvest Technology](https://learnplantscience.com/horticulture/post-harvest-technology/): Definition of the post harvest technology is preservation, conservation, quality control, processing, packaging, storage, distribution,marketing and utilization to meet the food and nutritional requirements consumers. Durable crops VS Perishable crops Durable crops Perishable crops Low moisture content High moisture content low rate respiration high respiration rate small unit size large unit size small rate of ... Read More "" » - [Growth control of horticultural crops](https://learnplantscience.com/horticulture/growth-control-of-horticultural-crops/): Methods of growth control of horticultural crops. Physical method Chemical method Biological method Physical methods Pruning Shoot tip and some other branches are removed allow room for new growth, healthier plants. it increases the productivity and make plants more manageable. Pruning methods Heading back – Removal of the shoot apex eliminates the effect of auxins, ... Read More "" » - [Organic farming](https://learnplantscience.com/horticulture/organic-farming/): Organic farming is an agricultural system that provide fresh, tasty, authentic foods while respecting the natural life cycle systems. Codex Alimentarius guidelines. (food law) Organic farming is regulated internationally by Codex Alimentarius Guidelines This guidelines are established by The united nations Food and Agricultural Organization (FAO) World Health Organization (WHO) International Federation of the Organic ... Read More "" » - [Soil water](https://learnplantscience.com/horticulture/soil-water/): some important terminologies with related soil water. Saturation capacity – Soil is at its maximum retain capacity. Field capacity – A measure of the maximum amount of the water that soil can hold. Permanent wilting point – The minimum soil moisture at which a plant wilt and no longer recover its turgidity. Available water content ... Read More "" » - [Chemical properties of soil.](https://learnplantscience.com/horticulture/chemical-properties-of-soil/): Main considering chemical properties of soil are given below. Cation exchange capacity (CEC) pH Salinity C:N ratio (Carbon to Nitrogen) Soil colloids – Finest clay and SOM (Soli Organic Matters) particles. The location for most physical and chemical activity. Soil colloids have larger surface areas due to their small size. Colloids has many negative charge ... Read More "" » - [Experimental Design Models](https://learnplantscience.com/statistics-experimental-design-data-analysis-using-r/experimental-design-models/): Mainly there are four experimental design models. Completely Randomized Design (CRD) Random Completely Block Design (RCBD) Split Plot Design Latin Square Design (LSD) Completely Randomized Design (CRD) Experimental unit in the population has an equal equally treated with the treatments/randomly treated. E.g. – Effect of the fertilizer is monitored of crop cultivation, plants (Experimental unit) ... Read More "" » - [Statistical Sampling Methods.](https://learnplantscience.com/statistics-experimental-design-data-analysis-using-r/statistical-sampling-methods/): Most commonly used statistical sampling methods are shown below. Random sampling Stratified sampling Cluster sampling Systematic sampling Random sampling Each member in the population has equal chance to being selected. This can be used when the population is homogeneous. E.g. – Select the plant leaves randomly for the measure the photosynthetic rate E.g – Plant ... Read More "" » - [Cultivation of Orchids](https://learnplantscience.com/horticulture/cultivation-of-orchids/): Categories Terrestrial – Bamboo Orchid Epiphytic Lithophytic Subterranean Horticultural classification Phalaenopsis type – Petals are broad and overlap on each other Cane type – Petals are thin and sometimes twisted Intermediate type – intermediate in size and shape between Phalaenopsis and cane type Orchid Hybridization Ascocenda (Ascocentrum x Vanda) The structure of Orchids, conform to ... Read More "" » - [Microorganisms in N2 cycle.](https://learnplantscience.com/uncategorized/microorganisms-in-n2-cycle/): This content is password-protected. To view it, please enter the password below. Password: - [Soil](https://learnplantscience.com/horticulture/soil/): Soil definition: Naturally weathered part of the earth, including organic matters affect on plant growth and plant performances. Soil genesis Soil is generated from the mother rocks and further developed from the natural and anthropogenic activities. Five major factors influencing soil formation Type of rock Climate Topography Organisms Time Soil formation comprises of two different ... Read More "" » - [Hydroponics](https://learnplantscience.com/horticulture/hydroponics/): Hydroponics is a technique used for growing plants in nutrient solutions with or without an artificial medium A major problems in growing crops in soil Presence of disease causing organisms Unsuitable soil reactions Compaction of soil Poor drainage Soil erosion Continuous cultivation cause soil infertility  Advantages of Hydroponic cultivation Maximum crop yield Crop production where ... Read More "" » - [Blotting Techniques](https://learnplantscience.com/molecular-biology/blotting-techniques/): Blotting Techniques mainly have four main steps Electrophoretic separation of protein/nucleic acid fragments in the sample Transfer to and immobilization on a solid support Binding of probe to the target molecule on membrane Visualization of bound probe Southern blotting – Allows DNA fragments to be identified Northern blotting – Allows RNA fragments to be identified ... Read More "" » - [Electrophoresis of Nucleic Acids.](https://learnplantscience.com/molecular-biology/electrophoresis-of-nucleic-acids/): Electrophoresis − the migration of a charged particle under the of an electric field. Migration rate/separation depends on: size, shape, charge The charge per unit length in any given fragment of DNA is the same since mobility of DNA molecules during gel electrophoresis The small DNA fragments move more easily through the gel pores. Requirements ... Read More "" » - [DNA/RNA QUANTIFICATION](https://learnplantscience.com/molecular-biology/dna-rna-quantification/): DNA and RNA quantitation is performed using various methods. Absorbance/spectrophotometric methods Gel electrophoresis – Agarose gel electrophoresis Fluorometric methods Absorbance method (UV spectrophotometer, NanoDrop) At 260 nm nucleic acids absorbs light most strongly At 280 nm proteins are absorbs light most strongly At 230 nm other chemical contamination absorbs light most strongly. DNA purity (protein ... Read More "" » - [Plasmid DNA extraction.](https://learnplantscience.com/molecular-biology/plasmid-dna-extraction/): Plasmid DNA may appear in several conformations. Covalently closed circular DNA (cccDNA) – both strands of the plasmids DNA are intact. (Supercoiled DNA, Relaxed circular DNA) Open circular DNA – One nucleotide stand is broken Super coiled DNA is move faster than open circular and genomic DNA because it compact conformation. Plasmid DNA extraction methods. ... Read More "" » - [RNA Extraction.](https://learnplantscience.com/molecular-biology/rna-extraction/): RNases enzyme is one of the main problem of the RNA extraction. that degraded the RNA because RNases is very stable, found every everywhere, active enzyme that do not required any co-factors and maintain activity even during the autoclaving. Avoiding RNase Contamination RNase inhibitors are added to the extraction buffer to inhibit the endogenous RNase: ... Read More "" » - [DNA extraction](https://learnplantscience.com/molecular-biology/dna-extraction/): The key steps of DNA extraction is give below. Sample disruption Clearing cell debris Purification Concentration DNA Sample disruption. rapid and complete disruption of cells in sample releasing DNA into lysate. there are several methods to disruption of the cell wall. Physical methods – grinding with mortar and pestle under liquid nitrogen. Chemical methods – ... Read More "" » - [Plant Improvement.](https://learnplantscience.com/horticulture/plant-improvement/): The goal of plant improvement is to create superior plants from existing ones (higher yield, improved quality, resistance to abiotic and biotic stress). Ability of a particular trait to be manipulated is determined by environment and the genotype. Heritability is the one of the most important concept in the plant breeding heritability is the ratio ... Read More "" » - [Plant Propagation.](https://learnplantscience.com/horticulture/plant-propagation/): Plant propagation is the creation of new plants from existing ones. There are two main types of plant propagation: asexual (vegetative propagation), sexual (seed propagation). Genetic control in propagation – in vegetative propagation plants are genetically similar to their parents. this does not improve the genetic diversity. In sexual propagation plants offspring plants are genetically ... Read More "" » - [Germplasm Conservation.](https://learnplantscience.com/plant-breeding/germplasm-conservation/): Germplasm is the living resource for genetic information in a plant. pass from one generation to another. Germplasm conservation is the preservation of these genetic information. Genetic erosion – Decline in the genetic variation in cultivation or natural population. Causes of genetic erosion. Crop domestication and spread of superior variations. Exploitation of the natural environment: ... Read More "" » - [Breeding methods for self pollinating plants.](https://learnplantscience.com/plant-breeding/breeding-methods-for-self-pollinating-plants/): The following are the main breeding methods for self pollinating plants: Mass selection Pure – line selection Hybridization Marker assisted selection synthetic populations Mass selection Mass selection is the process of selection of the crops breeding based on their overall phenotype rather than based on specific traits. Mass selection will improve the frequency of the ... Read More "" » - [Traits in the Plant Breeding](https://learnplantscience.com/plant-breeding/traits-in-the-plant-breeding/): Qualitative traits vs Quantitative traits Qualitative traits Quantitative traits Traits can be grouped Traits can be measured Determine by few gene Determine by many genes Each gene has a large contribution on traits Each gene has small contribution on phenotype Expression of the trait does not influence by the environment Expression of the trait influenced ... Read More "" » - [Evolution favors outcross breeding](https://learnplantscience.com/plant-breeding/evolution-favors-outcross-breeding/): Plants have mechanisms to avoid inbreeding mechanisms to favor out-cross breading Pre – pollination mechanisms – based on the floral biology Post – pollination mechanisms – self incompatibility Post – fertilization mechanisms. – Embryo abortion, inbreeding depression. Pre – pollination mechanisms Degree of the separation of male and female organs. Temporal separation of male and ... Read More "" » - [Introduction to Plant Breeding](https://learnplantscience.com/plant-breeding/introduction-to-plant-breeding/): Plant Breeding The application of art and science to improve plants for human benefit, such as increasing yield, making them more disease-resistant, and improving flavor. this is achieve by control through crossbreeding, genetic engineering, and so many methods. Crop domestication Crop domestication is the process that select the wild plant species that contains better suited ... Read More "" » - [Plant Microbiome](https://learnplantscience.com/microbiology/plant-microbiome/): The term “plant microbiome” refers to the collective community of microorganisms that live on and within plants. Microbial diversity is a trait that forms part of the extended phenotype of the host, and important on the health, fitness and the evolution Phyllosphere The phyllosphere is the aerial portion of the plant’s surface. It includes leaves, ... Read More "" » - [Sulfur Cycle](https://learnplantscience.com/microbiology/sulfur-cycle/): Major steps in the sulfur cycle. Sulfur deposition – Sulfate and elemental sulfur in are deposited in the atmosphere, plants, and other organisms. Sulfur oxidation – sulfur oxidizing bacteria convert hydrogen sulfide into elemental sulfur and sulfate. The green and purple sulfur bacteria oxidized the hydrogen sulfide for the photosynthesis; they live in the light. ... Read More "" » - [Nitrogen Cycle](https://learnplantscience.com/microbiology/nitrogen-cycle/): Main steps of nitrogen cycle Nitrogen fixation. Nitrification. Denitrification. Ammonification. Nitrogen assimilation. Nitrogen fixation Mainly two steps in nitrogen fixation; Biological N2 fixation (BNF) and Non-biological N2 fixation (NBNF). Biological N2 fixation is mainly done by prokaryotes using nitrogenase enzyme complex; it catalyzes the N2 to NH3 and this process is energy consuming reaction. These ... Read More "" » - [Carbon Cycle](https://learnplantscience.com/microbiology/carbon-cycle/): General major steps of the carbon cycle. Photosynthesis Respiration Decomposition Fossil fuel formation Fossil fuel burning Absorption into ocean Up taken by the plants Rock Weathering Methanogenesis The production of Methane Hydrogen, Carbon dioxide production – broken down the organic material and releasing hydrogen, carbon dioxide. Acetate production – carbon dioxide and hydrogen are converted ... Read More "" » - [QUORUM SENSING](https://learnplantscience.com/microbiology/quorum-sensing/): Quorum sensing is a type of cell-to-cell communication mechanism used by bacteria and other microorganisms to coordinate their behavior and activities. It involves the production and detection of signaling molecules called autoinducers, Which allow for the regulation of gene expression, allow bacteria to sense the density of the population, and enable bacteria to coordinate collective ... Read More "" » - [FACTORS AFFECTING BIOLOGICAL
RISK OF MICROORGANISMS](https://learnplantscience.com/microbiology/factors-affecting-biologicalrisk-of-microorganisms/): Mainly there are five factors that affecting the biological risk of the microorganisms nature of the microorganisms number of the microorganisms nature the route of the infection. Susceptibility of the microorganisms to treatments Susceptibility of the host Nature of the microorganisms base on the hazardous level there are 4 categories BSL – Bio Safety Level ... Read More "" » - [Spearman Correlation](https://learnplantscience.com/statistics-experimental-design-data-analysis-using-r/spearman-correlation/): The Spearman correlation is a non-parametric alternative to the linear correlation coefficient. Assumptions of Spearman Correlation Random sampling Independent measurements Data should be measurements counts or ordinal Steps in Spearman Correlation - [Mann Whitney U Test](https://learnplantscience.com/statistics-experimental-design-data-analysis-using-r/mann-whitney-u-test/): Mann Whitney U test is the alternative for the two independent sample t-test Assumption for Mann Whitney u test Random sampling Independent measurement Two population should same shape of distribution. Steps for Mann Whitney U test. - [Sign Test](https://learnplantscience.com/statistics-experimental-design-data-analysis-using-r/sign-test/): The sign test is used for hypothesis testing by concerning the value of the median for one population, and comparing the median differences for two variables for two dependent samples. Assumptions of the sign test. Random sampling Independent measurements Data should be measurement, counts or scores. Sign test for one population in Excel Step 1: ... Read More "" » - [Nonparametric Statistics.](https://learnplantscience.com/statistics-experimental-design-data-analysis-using-r/nonparametricstatistics/): Nonparametric statistics deals with median rather than mean, because mean can be easily influenced by the outliers or skewness of data, and data are not normally distributed. The main difference between parametric and nonparametric tests is that in parametric tests, data are normally distributed, whereas in nonparametric tests, data are not normally distributed. Assumptions of ... Read More "" » - [Descriptive statistics for phylogenetic trees](https://learnplantscience.com/phylogenetic/descriptive-statistics-for-phylogenetic-trees/): Homology Vs Homoplasy Homology is similarity between trait share from common ancestor, most of the homologous characters are recently derived shared characters. Homoplasy is the similarity that are most likely superficially similar (identical on the surface but there is no genetic relation) due to independent evolution and cause misleading of the phylogenetic inferences. The reasons ... Read More "" » - [Summarizing Evolutionary Trees](https://learnplantscience.com/phylogenetic/summarizing-evolutionary-trees/): Evolutionary Trees Important terminologies Rooted trees – this tree type shows evolutionary relationships, direction of evolution and the ancestral state Unrooted trees – this tree type only shows the Phylogenetic relationships. Common ancestor – Simply to choose a point (hypothetical point) on the tree as representing the earliest time in the evolutionary history of the sequence data. ... Read More "" » - [Linear Regression Analysis Using R](https://learnplantscience.com/statistics-experimental-design-data-analysis-using-r/linear-regression-analysis-using-r/): Linear regression analysis describe the relation between two or more variables,and find the best fit line to the graph and equation of the straight line; that is used for make predictions. Assumption of Regression Analysis Random sampling independent measurements or observations. Dependent variable should be normally distributed equal variance. R2 = Coefficient of Determination/ Linear ... Read More "" » - [Pearson’s correlation (r)](https://learnplantscience.com/uncategorized/pearsons-correlation/): Pearson’s correlation (r) check the relationships between two or more variables; there are three types of correlations: simple correlations, multiple correlations, and partial correlations. The correlation between two variables is known as simple correlation. Multiple correlation is the correlation between three or more variables. Partial correlation – Two or more variables are involved, check the ... Read More "" » - [Statistical Errors.](https://learnplantscience.com/uncategorized/statistical-errors/): There are two types of statistical errors. Type 1 error Type 2 error Type 1 error Reject the null hypothesis when null hypothesis is true Type 2 error Fail to reject the null hypothesis when null hypothesis is false Type 1 errors are more dangerous than type 2 errors. - [ANOVA test](https://learnplantscience.com/statistics-experimental-design-data-analysis-using-r/anova-test/): Analysis of variance An ANOVA test is used to compare means between more than two groups. One-way ANOVA uses one independent variable, and two-way ANOVA uses two independent variables.(two factors that are being tested simultaneously) Two main aim of ANOVA tests To explain the relative contribution of the different factors or combination of different factors ... Read More "" » - [Z - test & T - Test in R](https://learnplantscience.com/statistics-experimental-design-data-analysis-using-r/z-test-t-test-in-r/): Assumption of Z-test samples are randomly selected from the population Population is normally distributed population variance is known Assumption of T-test samples are randomly selected from the population population is normally distributed populations variance is unknown sample data are continuous Z-test VS T-test Z test can be only apply when the population variance is known ... Read More "" » - [Introduction to experiment design](https://learnplantscience.com/statistics-experimental-design-data-analysis-using-r/introduction-to-experiment-design/): Validity of a experiments First we consider the validity of the experiment the are three main validates. statistical validity, internal validity, and external validity In statistical validity three main hypothesis are made – normality, Homogeneity of the variance, independent of the variance Internal validity is the how far relationship between independent and dependent variables. External ... Read More "" » ## Pages - [Home](https://learnplantscience.com/): Learn Plant Science Explore the green world with us     Expand your plant science knowledge   Discover Plant Breeding, Ecology, Horticulture, Plant Molecular Biology, Phylogenetic and more. Categories Coming soon! Interactive learning experiences, including quizzes and games, to make learning more engaging and fun. Contact us - [Contact form](https://learnplantscience.com/contact-form/) - [Privacy Policy](https://learnplantscience.com/privacy-policy-2/): Who we are Our website address is: https://learnplantscience.com. Comments When visitors leave comments on the site we collect the data shown in the comments form, and also the visitor’s IP address and browser user agent string to help spam detection. An anonymized string created from your email address (also called a hash) may be provided ... Read More "" » - [Phylogenetic Analysis](https://learnplantscience.com/phylogenetic-analysis/): Table of content Introduction to the phylogenetic Phylogenetic data Analysis of the molecular phylogenetic - [Statistics - Experimental Design & Data Analysis Using R](https://learnplantscience.com/experimental-design/): Table of contents Introduction to experiment design Mean comparison test Linear Correlations Regression Analysis Regression VS correlations - [Taxonomic Characters](https://learnplantscience.com/taxonomic-characters/): To produce a classification of organisms involves comparative data and analysis of data are used as taxonomic characters. Three (03) different types of data The organism itself – morphology, cytology, genetics & chemistry Organism-organism interactions: cytogenetics, reproductive biology Organism-environment interactions: distribution, ecology Reflect the structural composition or the architecture of the plant, such as anatomy, ... Read More "" » - [APG Classification System](https://learnplantscience.com/apg-classification/): APG Classification system is referred to a Angiosperm Group Classification system In the past, many classifications were done by individual botanists or small groups. The result is large numbers of systems such as… APG classification systems were published in 1998,2003,2009,2016. These classifications are independent of morphological characters. Less convergent evolution of characters. Many more characters, ... Read More "" » ## Optional - [Agent (MCP protocol)](websites-agents.hostinger.com/learnplantscience.com/mcp) [comment]: # (Generated by Hostinger Tools Plugin)