Chi-square Test- Definition, Formula, Uses, Table, Examples, Applications

Chi-square test

What is a Chi-square test? A Chi-square test is performed to determine if there is a difference between the theoretical population parameter and the observed data. Chi-square test is a non-parametric test where the data is not assumed to be normally distributed but is distributed in a chi-square fashion. It allows the researcher to test factors like a number of factors like the goodness of fit, the significance of population variance, and the homogeneity or difference in population variance. This … Read more

Homeostasis- Definition, Types, Examples, Applications

Homeostasis- Definition, Types, Examples, Applications

Homeostasis Definition Homeostasis is the ability of living systems to maintain a steady and uniform internal environment to allow the normal functioning of the systems. It is the tendency to achieve equilibrium against various natural and environmental factors. Homeostasis results in a dynamic equilibrium, where continuous changes keep on taking place, and yet steady conditions are maintained. Homeostasis is mainly involved in managing various internal variables of the living system like body temperature, pH of various fluids, the concentration of … Read more

Bile Esculin Test- Principle, procedure, results, uses, limitations

Bile Esculin Test

What is the Bile Esculin Test? The bile-esculin test is a biochemical test performed to differentiate Enterococci and group D Streptococci from non-group D viridans group Streptococci on the basis of their ability to hydrolyze esculin. Many organisms are capable of hydrolyzing esculin, but only a few of them can do so in the presence of bile (4% bile salts or 40% bile.). Thus, this property is utilized to identify organisms of a particular group. The Bile-esculin test is performed … Read more

Homozygous vs Heterozygous- Definition, 10 Differences, Examples

Differences between Homozygous and Heterozygous

Homozygous Definition Homozygous is a genetic condition where an individual inherits the same alleles of a gene from both the parents. In homozygous chromosomes, both alleles are either dominant or recessive. The dominant trait is represented by two capital letters (XX) and the recessive trait is represented by two lowercase letters (xx). Homozygous-dominant chromosomes carry two copies of the allele that codes for the dominant trait whereas the homozygous-recessive chromosomes carry two copies of the allele that codes for the recessive trait. … Read more

Apoptosis- definition, pathways, assay, examples (vs Necrosis)


What is Apoptosis? Apoptosis is a normal genetically programmed cell death where an aging cell at the end of its life cycle shrinks and its remaining fragments are phagocytosed without any inflammatory reaction. The term apoptosis was first introduced in a paper in 1972 by Kerr, Wyllie, and Currie to describe a morphologically distinct type of cell death. It consists of a series of biochemical changes that lead to changes in the cell’s morphology or death. It results in the … Read more

Heterochromatin vs Euchromatin- Definition, 16 Differences, Examples

Differences Between Heterochromatin and Euchromatin

Heterochromatin Definition Heterochromatin is a tightly packed or condensed DNA that is characterized by intense stains when stained with nuclear stains, containing transcriptionally inactive sequences. It exists in multiple variations, up to four to five state, each of which is marked with combinations of epigenetic markers. The staining of heterochromatin might result in heteropycnosis; heteropycnosis is the differential staining of parts of chromosomes. This chromosome is different from euchromatin in that the genes in these chromosomes are usually inactivated and … Read more

Epithelial tissue vs Connective tissue- Definition, 15 Differences, Examples

Differences between epithelial tissue and connective tissue

Epithelial Tissue Definition Epithelial tissue is a type of animal tissue, consisting of closely aggregated polyhedral cells connected firmly to one another in the form of cellular sheets that line the interior of hollow organs and cover the body surface. Cells in epithelial tissue or epithelium (epithelia; plural) are arranged in continuous sheets, in either single or multiple layers. The shapes and sizes of cells in the epithelium tissue range from tall columnar to cuboidal to low squamous, and often … Read more

Iodine Test- Definition, Principle, Procedure, Result, Uses

Iodine Test- Definition, Principle, Procedure, Result, Uses

Iodine Test Definition Iodine test is a chemical test used to distinguish mono- or disaccharides from certain polysaccharides like amylase, dextrin, and glycogen. This test has a variation termed starch-iodine test that is performed to indicate the presence of glucose made by plants in the leaves. Objectives of Iodine Test To detect the presence of polysaccharides, primarily starch. Principle of Iodine Test Iodine test is based on the fact that polyiodide ions form colored adsorption complex with helical chains of … Read more

Chromosome vs Chromatid- Definition, 11 Major Differences, Examples

Differences between Chromosome and Chromatid (Chromosome vs Chromatid)

Chromosome Definition A chromosome is a thread-like structure present in the nucleus or nuclear region of the cytoplasm that is made up of a single molecule of DNA (Deoxyribonucleic acid) and proteins, carrying some or all genetic materials of an organism. These chromosomes are only visible under the light microscope during the metaphase of the cell cycle where the chromosomes line up in the center of the cell. Prokaryotes have a single circular chromosome that is organized in the nucleoid … Read more

Types of Centrifuge and Centrifugation (definition, principle, uses)

Types of Centrifuge and Centrifugation

Centrifuge definition A centrifuge is a device used to separate components of a mixture on the basis of their size, density, the viscosity of the medium, and the rotor speed. The centrifuge is commonly used in laboratories for the separation of biological molecules from a crude extract. In a centrifuge, the sample is kept in a rotor that is rotated about a fixed point (axis), resulting in strong force perpendicular to the axis. There are different types of centrifuge used … Read more