Genetics

Genetics is a branch of natural science that deals with heredity due to the transmission of genes, gene regulation, and gene manipulation.

Genetics is a connecting link between many disciplines like microbiology, biotechnology, medicine, and agriculture.
Studies involving genes and chromosomes of living beings began quite late as it requires significant advances in the microscopy area.
The influence of heredity and its application of cultivation and production improved organisms, however, had been recognized since ancient times.
The study of genes and genetics began as a major concept after studies made by Mendel on pea plants. It was further strengthened and flourished by the works of Morgan.
Eventually, genetics became a distinct area of study with the identification of genes and the study of genes at different levels, including their role in the cell, their regulation, and their expression.
Initially, genetics was limited to understanding the concept and process of heredity via techniques like the formation of Punnet’s square. With the development of techniques like X-ray diffraction, the structure of DNA, and the presence of genetic code were established. This paved the way for modern genetics.
Modern genetics focuses on the chemical composition of structures found in genes like the DNA that influences the chemical reactions taking place in the cell.
Gene expression is influenced by two major factors; the genetic composition and the influence of the environment.
The influence of the environment on gene expression can be distinctly observed in green plants where the gene responsible for the formation of chlorophyll is only expressed in the presence of sunlight.
Genes, through the proteins they encode, determine how efficiently foods and chemicals are metabolized, how effectively toxins are detoxified, and even how vigorously infections are targeted.
Processes like mutations are now a significant cause of major genetic diseases. The mutations might arise due to a complex combination of genetic, behavioral, and environmental factors.

Natural vs Artificial Selection- Definition, 17 Major Differences, Examples

December 30, 2020August 25, 2020 by Anupama Sapkota

Differences Between Natural and Artificial Selection

Natural selection definition Natural selection is a process of adaptation by an organism to the changing environment by bringing selective changes to its genotype or genetic composition. Natural selection is one of the four primary mechanisms of evolution, along with mutation, genetic drift, and migration. Charles Darwin popularized the concept of natural selection during his studies on evolution. According to …

Phenotype vs Genotype- Definition, 10 Major Differences, Examples

December 30, 2020July 29, 2020 by Anupama Sapkota

Differences between Phenotype and Genotype

Phenotype Definition Phenotype is a term used in genetics to refer to all the observable traits in organisms as a result of the interaction of the genotype with the environment. The term ‘pheno’ in ‘phenotype’ refers to ‘observe’ and thus phenotype is used to indicate the observable characteristics in organisms like its height and color. The phenotype of an organism …

Incomplete dominance vs Co-dominance- Definition, 10 Differences, Examples

December 30, 2020July 25, 2020 by Anupama Sapkota

Differences between Incomplete dominance and Co-dominance

Image Source: Spencerbaron and YassineMrabet. Incomplete dominance definition Incomplete dominance is a mechanism of dominance in heterozygotes, where the dominant allele does not entirely overcome the phenotypic expression of the recessive allele, and there occurs an intermediate phenotype in the heterozygote. Incomplete dominance is also called partial dominance or semi-dominance as the phenotype resulting from the genotype is a blend …

Homozygous vs Heterozygous- Definition, 10 Differences, Examples

December 30, 2020July 24, 2020 by Anupama Sapkota

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 …

Heterochromatin vs Euchromatin- Definition, 16 Differences, Examples

December 30, 2020July 21, 2020 by Anupama Sapkota

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 …

Chromosome vs Chromatid- Definition, 11 Major Differences, Examples

December 30, 2020July 17, 2020 by Anupama Sapkota

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 …

Epidemiological Markers

October 8, 2020September 18, 2019 by Sagar Aryal

Epidemiological Markers Epidemiological markers are biological markers that are used to characterize microorganisms or discriminate between genomes based on the genetic variation among microbial isolates. Uses of Epidemiological Markers Epidemiological markers are mostly used for strain typing. It is used to: Classify isolates of microorganisms Catalogue genetic variation Define relatedness or lack of it between microbial species or genera It …

Non-Mendelian Inheritance

October 8, 2020November 9, 2018 by Sagar Aryal

Non-Mendelian Inheritance Mendelian inheritance patterns involve genes that directly influence the outcome of an organism’s traits and obey Mendel’s laws. Most genes in eukaryotic species follow a Mendelian pattern of inheritance. However, there are many that do not. Non-Mendelian inheritance is a general term that refers to any pattern of inheritance in which traits do not segregate in accordance with Mendel’s laws. …

Extranuclear Inheritance- Cytoplasmic Factors and Types

October 8, 2020October 30, 2018 by Sagar Aryal

Extranuclear Inheritance- Cytoplasmic Factors and Types Though, the genes of nuclear chromosomes have a significant and key role in the inheritance of almost all traits from generations to generations, they altogether cannot be considered as the sole vehicles of inheritance. Certain experimental evidences suggest the occurrence of certain extranuclear genes or DNA molecules in the cytoplasm of many prokaryotic and …

Hardy-Weinberg Equilibrium

October 8, 2020October 26, 2018 by Sagar Aryal

Hardy-Weinberg Equilibrium The Hardy–Weinberg principle, also known as the Hardy–Weinberg equilibrium, model, theorem, or law explains that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences. The law was proposed by a British mathematician Hardy and a German physician Weinberg (1908) independently. Both the ideas together is called as the Hardy-Weinberg law equilibrium …