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.

Chromosomal Mutation- Definition, Causes, Mechanism, Types, Examples

March 11, 2021 by Anupama Sapkota

What are Chromosomes? Chromosomes are long thread-like structures of DNA that contain part or all of the genetic material of an organism. Chromosomes exist in a complex three-dimensional structure which is essential in transcriptional regulation. Chromosomes exhibit unique compactness as the unraveled form of the chromosome would be metered in length, but the compact form can be easily placed within …

Frameshift Mutation- Definition, Causes, Mechanism, Applications, Examples

March 11, 2021 by Anupama Sapkota

Frameshift mutation definition A frameshift mutation is a type of genetic mutation resulting from the alteration of a number of nucleotides in DNA sequences that are not multiple of three. Frameshift mutation occurs as a result of a change in the reading frame of the sequence. Since the codons for gene expression occur in the form of triplets, the difference …

Silent Mutation- Definition, Causes, Mechanism, Applications, Examples

March 11, 2021 by Anupama Sapkota

What are Silent mutations? Silent mutations are mutations where the changes in the nucleotide sequence of DNA do not produce any observable effect on the organism. The change in nucleotide doesn’t produce a change in the amino acid sequence or the structure and function of the protein. Silent mutations are also termed neutral mutations as these do not cause any …

Nonsense Mutation- Definition, Causes, Mechanism, Applications, Examples

March 11, 2021 by Anupama Sapkota

Nonsense mutation definition A nonsense mutation is a type of mutation where a premature stop codon is added to a sequence which hinders the further translation of the protein-coding gene. The nonsense mutation is classified as a loss-of-function change where the mutation impairs the production of a particular protein. Nonsense mutation, like most other mutations, can have a range of …

Missense Mutation- Definition, Causes, Mechanism, Types, Examples

March 11, 2021March 11, 2021 by Anupama Sapkota

Missense mutation definition A missense mutation is a type of mutation where the alteration of a nucleotide base in a gene sequence results in the translation of different amino acids in the protein. A missense mutation is a type of nonsynonymous substitution in a DNA sequence, indicating that the mutation results in some kind of effect on the resulting sequence. …

Point mutation- Definition, Causes, Mechanism, Types, Examples, Applications

March 11, 2021March 7, 2021 by Anupama Sapkota

Point mutation definition Point mutation is a type of genetic mutation where one of the base pairs in the DNA sequence is altered either by insertion or deletion. Point mutation, as the name indicates, occurs at a particular point of the DNA sequence as a result of changes in one particular base pair. Usually, point mutations arise as a result …

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 …