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This list of research methods in biology is an index to articles about research methodologies used in various branches of biology.
Research design | Utility | Potential analysis |
---|---|---|
Between-group design | Experiment that has two or more groups of subjects each being tested by a different testing factor simultaneously | Student's t-test, Analysis of variance, Mann–Whitney U test |
Repeated measures design | A research design that involves multiple measures of the same variable taken on the same or matched subjects either under different conditions or over two or more time periods. [1] | Paired t-test, Wilcoxon signed-rank test |
Analysis | Utility | Branch |
---|---|---|
Dose–response curves | Graph that shows the magnitude of the response of an organism, as a function of exposure (or doses) to a stimulus or stressor (usually a chemical) after a certain exposure time [2] | Physiology |
Electroencephalogram | Graph that shows voltage fluctuations resulting from ionic current within the neurons of the brain [3] | Neuroscience |
Electrocardiogram | Graph of voltage versus time of the electrical activity of the heart [4] using electrodes placed on the skin | Physiology |
Manhattan plot | Used to display data with a large number of data-points, many of non-zero amplitude, and with a distribution of higher-magnitude values. The plot is commonly used in genome-wide association studies (GWAS) to display significant SNPs. [5] | Genetics |
Pedigree chart | Used to show the occurrence of phenotypes of a particular gene or organism and its ancestors from one generation to the next, [6] [7] [8] most commonly humans, show dogs, [9] and race horses | Genetics |
Phylogenetic tree | Used to show the evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical or genetic characteristics | Systematics, Evolutionary biology |
Population pyramid | Used to illustrate the distribution of a population (typically that of a country or region of the world) by age groups and sex; it typically forms the shape of a pyramid when the population is growing [10] | Population ecology |
Punnett square | Used to predict the genotypes of a particular cross or breeding experiment | Genetics |
Analysis | Utility | Type |
---|---|---|
Analysis of variance | A collection of statistical models and their associated estimation procedures (such as the "variation" among and between groups) used to analyze the differences among means | Statistical model |
Chi-squared test | A statistical hypothesis test that is valid to perform when the test statistic is chi-squared distributed under the null hypothesis, specifically Pearson's chi-squared test and variants thereof | Statistical hypothesis test |
Mann–Whitney U test | A statistical hypothesis test of the null hypothesis that, for randomly selected values X and Y from two populations, the probability of X being greater than Y is equal to the probability of Y being greater than X | Nonparametric statistics |
Student's t-test | Any statistical hypothesis test in which the test statistic follows a Student's t-distribution under the null hypothesis | Parametric statistics |
Method | Utility | Branches |
---|---|---|
Agarose gel electrophoresis | Used to separate a mixed population of macromolecules such as DNA or proteins in a matrix of agarose, one of the two main components of agar | Biochemistry, Molecular biology, Genetics |
Animal Model | Used for researching diseases and disorders in humans. Some animals may have human-like traits, such as mice, while others may have traits that are ideal for research, such as the squid giant axon | Biochemistry, Neuroscience, Physiology |
Biological ablation | Used to remove a biological structure or functionality | Genetics, Physiology |
Calcium imaging | Used to optically measure the status of calcium ions (Ca2+) in an isolated cell, tissue or medium | Physiology |
Cell isolation | Process of separating individual living cells from a solid block of tissue or cell suspension | Cell biology |
Centrifugation | Use of centrifugal force to separate particles from a solution according to their size, shape, density, medium viscosity, and rotor speed | Cell biology, Biochemistry |
CRISPR gene editing | Used to modify the genomes of living organisms based on a simplified version of the bacterial CRISPR-Cas9 antiviral defense system | Molecular biology |
DNA sequencer | Used to automate the DNA sequencing process | Genetics, Molecular biology |
Enzyme-linked immunosorbent assay (ELISA) | Used to detect the presence of a ligand (commonly a protein) in a liquid sample using antibodies directed against the protein to be measure | Biochemistry, Molecular biology |
Gene knockout | Used to make one of an organism's genes inoperative ("knocked out" of the organism) | Molecular biology, Genetics |
Immunostaining | Used of an antibody-based method to detect a specific protein in a sample | Molecular biology, Biochemistry |
Intracellular recording | Used to measure the voltage across a cell membrane | Neuroscience, Electrophysiology |
Microarray | Assays (tests) large amounts of biological material using high-throughput screening miniaturized, multiplexed and parallel processing and detection methods | Genetics, Molecular biology |
Microelectrode array | Devices that contain multiple (tens to thousands) microelectrodes through which neural signals are obtained or delivered, essentially serving as neural interfaces that connect neurons to electronic circuitry | Neuroscience |
Microscope | Used to examine objects that are too small to be seen by the naked eye | Cell biology |
Molecular cloning | Used to assemble recombinant DNA molecules and to direct their replication within host organisms. [11] | Molecular biology |
Northern blot | Used to study gene expression by detection of RNA (or isolated mRNA) in a sample. [12] [13] | Molecular biology |
Optogenetics | Uses light to control neurons that have been genetically modified to express light-sensitive ion channels | Neuroscience |
Oscilloscope | Used to graphically displays varying signal voltages, usually as a calibrated two-dimensional plot of one or more signals as a function of time | Neuroscience, Physiology |
Paper chromatography | Used to separate coloured chemicals or substances. [14] | Molecular biology |
Patch clamp | Used to study ionic currents in individual isolated living cells, tissue sections, or patches of cell membrane | Electrophysiology, Neuroscience |
Polymerase chain reaction (PCR) | Used to rapidly make millions to billions of copies (complete copies or partial copies) of a specific DNA sample, allowing scientists to take a very small sample of DNA and amplify it (or a part of it) to a large enough amount to study in detail | Genetics, Molecular biology |
Somatic cell nuclear transfer | Used for creating a viable embryo from a body cell and an egg cell | Developmental biology |
Southern blot | Used to detect specific DNA sequence in DNA samples | Molecular biology |
Test cross | Used to determine whether an individual is homozygous or heterozygous dominant | Genetics |
Voltage clamp | Used to measure the ion currents through the membranes of excitable cells, such as neurons, while holding the membrane voltage at a set level. [15] | Physiology, Neuroscience |
Western blot | Used analytical technique in molecular biology and immunogenetics to detect specific proteins in a sample of tissue homogenate or extract | Molecular biology |
X-ray crystallography | Used to determine the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions | Structural biology |
Method | Utility | Branches |
---|---|---|
Distance sampling | Used for estimating the density and/or abundance of populations | Ecology |
Mark and recapture | Used to estimate an animal population's size where it is impractical to count every individual. [16] | Ecology |
Model | Utility | Branches |
---|---|---|
Exponential integrate-and-fire | Describes compact and computationally efficient nonlinear spiking neuron models with one or two variables | Neuroscience |
FitzHugh–Nagumo model | Describes a prototype of an excitable system (e.g., a neuron) | Neuroscience |
Hardy–Weinberg principle | States that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences | Genetics, Evolutionary biology |
Hodgkin–Huxley model | Describes how action potentials in neurons are initiated and propagated | Neuroscience |
Infinite sites model | Allows for the calculation of heterozygosity, or genetic diversity, in a finite population and for the estimation of genetic distances between populations of interest [17] | Evolutionary biology |
Logistic growth | Describes the growth of a population as exponential, followed by a decrease in growth, and bound by a carrying capacity due to environmental pressures. [18] | Ecology |
Lotka–Volterra equations | Describe the dynamics of biological systems in which two species interact, one as a predator and the other as prey | Ecology |
Moran process | Stochastic process that describes finite populations | Genetics |
Species–area relationship | describes the relationship between the area of a habitat, or of part of a habitat, and the number of species found within that area | Ecology |
Algorithm | Utility | Branches |
---|---|---|
Evolutionary algorithm | Uses mechanisms inspired by biological evolution. Candidate solutions to the optimization problem play the role of individuals in a population, and the fitness function determines the quality of the solutions. | Neuroscience |
Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with developmental delays, mild to moderate intellectual disability, and characteristic physical features. There are three types of Down syndrome, all with the same features: Trisomy 21, the most common type; Mosaic Down syndrome, and Translocation Down syndrome.
Genetics is the study of genes, genetic variation, and heredity in organisms. It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene.
Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic information of their parents. Through heredity, variations between individuals can accumulate and cause species to evolve by natural selection. The study of heredity in biology is genetics.
Molecular biology is a branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions.
Neuroscience is the scientific study of the nervous system, its functions and disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, developmental biology, cytology, psychology, physics, computer science, chemistry, medicine, statistics, and mathematical modeling to understand the fundamental and emergent properties of neurons, glia and neural circuits. The understanding of the biological basis of learning, memory, behavior, perception, and consciousness has been described by Eric Kandel as the "epic challenge" of the biological sciences.
Zoology is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one of the primary branches of biology. The term is derived from Ancient Greek ζῷον, zōion ('animal'), and λόγος, logos.
Cardiomyopathy is a group of primary diseases of the heart muscle. Early on there may be few or no symptoms. As the disease worsens, shortness of breath, feeling tired, and swelling of the legs may occur, due to the onset of heart failure. An irregular heart beat and fainting may occur. Those affected are at an increased risk of sudden cardiac death.
Molecular genetics is a branch of biology that addresses how differences in the structures or expression of DNA molecules manifests as variation among organisms. Molecular genetics often applies an "investigative approach" to determine the structure and/or function of genes in an organism's genome using genetic screens.
Mathematical and theoretical biology, or biomathematics, is a branch of biology which employs theoretical analysis, mathematical models and abstractions of living organisms to investigate the principles that govern the structure, development and behavior of the systems, as opposed to experimental biology which deals with the conduction of experiments to test scientific theories. The field is sometimes called mathematical biology or biomathematics to stress the mathematical side, or theoretical biology to stress the biological side. Theoretical biology focuses more on the development of theoretical principles for biology while mathematical biology focuses on the use of mathematical tools to study biological systems, even though the two terms are sometimes interchanged.
Genetic genealogy is the use of genealogical DNA tests, i.e., DNA profiling and DNA testing, in combination with traditional genealogical methods, to infer genetic relationships between individuals. This application of genetics came to be used by family historians in the 21st century, as DNA tests became affordable. The tests have been promoted by amateur groups, such as surname study groups or regional genealogical groups, as well as research projects such as the Genographic Project.
Researchers have investigated the relationship between race and genetics as part of efforts to understand how biology may or may not contribute to human racial categorization. Today, the consensus among scientists is that race is a social construct, and that using it as a proxy for genetic differences among populations is misleading.
Human genetics is the study of inheritance as it occurs in human beings. Human genetics encompasses a variety of overlapping fields including: classical genetics, cytogenetics, molecular genetics, biochemical genetics, genomics, population genetics, developmental genetics, clinical genetics, and genetic counseling.
Sewall Green Wright FRS(For) Honorary FRSE was an American geneticist known for his influential work on evolutionary theory and also for his work on path analysis. He was a founder of population genetics alongside Ronald Fisher and J. B. S. Haldane, which was a major step in the development of the modern synthesis combining genetics with evolution. He discovered the inbreeding coefficient and methods of computing it in pedigree animals. He extended this work to populations, computing the amount of inbreeding between members of populations as a result of random genetic drift, and along with Fisher he pioneered methods for computing the distribution of gene frequencies among populations as a result of the interaction of natural selection, mutation, migration and genetic drift. Wright also made major contributions to mammalian and biochemical genetics.
A biologist is a scientist who conducts research in biology. Biologists are interested in studying life on Earth, whether it is an individual cell, a multicellular organism, or a community of interacting populations. They usually specialize in a particular branch of biology and have a specific research focus.
Acrodermatitis enteropathica is an autosomal recessive metabolic disorder affecting the uptake of zinc through the inner lining of the bowel, the mucous membrane. It is characterized by inflammation of the skin (dermatitis) around bodily openings (periorificial) and the tips of fingers and toes (acral), hair loss (alopecia), and diarrhea. It can also be related to deficiency of zinc due to other, i.e. congenital causes.
Sphingolipidoses are a class of lipid storage disorders or degenerative storage disorders caused by deficiency of an enzyme that is required for the catabolism of lipids that contain ceramide, also relating to sphingolipid metabolism. The main members of this group are Niemann–Pick disease, Fabry disease, Krabbe disease, Gaucher disease, Tay–Sachs disease and metachromatic leukodystrophy. They are generally inherited in an autosomal recessive fashion, but notably Fabry disease is X-linked recessive. Taken together, sphingolipidoses have an incidence of approximately 1 in 10,000, but substantially more in certain populations such as Ashkenazi Jews. Enzyme replacement therapy is available to treat mainly Fabry disease and Gaucher disease, and people with these types of sphingolipidoses may live well into adulthood. The other types are generally fatal by age 1 to 5 years for infantile forms, but progression may be mild for juvenile- or adult-onset forms.
Multicystic dysplastic kidney (MCDK) is a condition that results from the malformation of the kidney during fetal development. The kidney consists of irregular cysts of varying sizes. Multicystic dysplastic kidney is a common type of renal cystic disease, and it is a cause of an abdominal mass in infants.
Samuel Karlin was an American mathematician at Stanford University in the late 20th century.
A species (pl. species) is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour, or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined.
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