Genetics
DEFINITION:
Genetics is
the study of how genes work and how they behave. Genes are molecular
instructions made up of DNA (deoxyribonucleic acid) that are found inside the
cells of all organisms, from bacteria to humans. Genes, which are found in one
or more chromosomes, determine an organism's characteristics, or traits. The
genome is the collection of all of an organism's genes. To put it another way,
the genome is divided into chromosomes, which contain genes, which are formed from
DNA.
EXPLANATION:
Geneticists
want to know how cells use and govern the information encoded in genes, as well
as how it is passed down from generation to generation. They also look into how
minor genetic differences might affect an organism's development or cause
disease. Classical genetics refers to genetic approaches and procedures that
predate the development of molecular genetics, which investigates the structure
and function of genes at the molecular level. Classical genetics is primarily
concerned with the way by which genetic features are transmitted in plants and
animals, and it remains the foundation for all other issues in genetics. These
traits are classed as dominant (always expressed), recessive (subordinate to a
dominant trait), intermediate (partially expressed), or polygenic (either
expressed or not expressed) (due to multiple genes). Furthermore, the features
are either sex-linked (due to the action of a gene on one of the sex
chromosomes) or autosomal (due to the action of a gene on one of the sex
chromosomes) (result from the action of a gene on a chromosome other than a sex
chromosome). Gregor Mendel, an Austrian monk, pioneered classical genetics by
tracing the inheritance patterns of specific features in pea plants and
demonstrating that they could be quantitatively expressed ("Mendel's
laws"). Experiments on Plant Hybridization, Mendel's 1865 article, went
mostly overlooked until the early twentieth century. The inheritance patterns
discovered by Mendel are currently used in the study of genetic illnesses.
Molecular
genetics uses genetics and molecular biology tools to study the development,
structure, and function of macromolecules that are necessary to live (such as
nucleic acids and proteins), as well as their role in cell replication and
genetic information transfer. The revelation of the structure of DNA by James
Watson and Francis Crick in 1953 considerably expanded the research options
available to geneticists. In the 1970s, scientists were able to start
sequencing genes (determining the exact order of the four subunits of DNA —
adenine, guanine, cytosine, and thymine); cloning genes (producing a replica of
a gene from one organism), and moving genes from one organism to another to
create genetically modified organisms thanks to the discovery of restriction
enzymes (which catalyze the cleavage of DNA at specific sites to produce
discrete fragments) (GMOs). Recombinant DNA technology or genetic engineering
refers to the combination of the two methods.
GENETICS
SUBDISCIPLINES
Genetics of
Populations, Quantitative Genetics, and Ecological Genetics
Population
genetics, quantitative genetics, and ecological genetics are all subfields of
classical genetics (supplemented with modern molecular genetics). Though they
all investigate populations of species, their focus differs slightly. Natural
selection, mutations, and migration all influence the distribution of genes,
and population genetics analyses how their frequencies change as a result of
these influences. Quantitative genetics is the study of continuous traits (such
as height or weight) that do not exhibit straightforward Mendelian inheritance
because they are the product of the interplay of many different genres. It is
based on population genetics. Ecological genetics builds on the fundamental
ideas of population genetics, but it is more specifically focused on ecological
challenges, such as the link between species and their surrounding environments.
Medical
Genetics
The
application of genetics to medicine is known as medical genetics. Clinical
genetics (the diagnosis and treatment of genetic illnesses), cytogenetics (the
study of chromosomes under a microscope), molecular genetics, and genetic counseling
are all examples of medical genetics (education and guidance offered by
professional advisors to help people make informed decisions based on personal
genetic information).
Genetics of Behavior
Behavioral
genetics is the study of how heredity influences animal behavior. Behavioral
genetics is the study of the genetic foundation of personality as well as the
causes and effects of human problems like mental illness, substance misuse,
violence, and social attitudes in humans.
Genomics
Genomics is
the study of large-scale genetic patterns across a species' genome. The data
obtained from genome sequence data also indicates what genes perform, how
they're controlled, and how they interact. The Human Genome Project, which is
now complete, has developed a genetic blueprint for creating a human person.
Researchers will be able to use this crucial knowledge to find the genetic
contributions to diseases, build highly effective diagnostic tools and
therapies, and better understand people's health requirements based on their
genetic makeup.