What is Genetics
Genetic is the science that studies the behavior and nature of genes, a gene is a basic unit of heredity, so the genetics studies the variation and heredity in living organisms.
Short history of Genetics
- Gregor Mendel is the father of Genetics, in 1865, After many experiences on hybridizing pea plants he reported that many series of traits passed down through generations.
- In 1866, Mendel noted certain patterns of inheritance seemed to be transmitted independently of one another.
- It wasn’t until 1900 that the scientific community recognize the observation of Mendel, and thus when three Europeans botanists reported the result of their breeding experiments and liked it to Mendel’s work.
- The biologist at the university of Cambridge, William Bateson was exited to study the relation between Mendel’s observations and evolution, and he recruited for that a number of young scientist women. Later they noted that Mendel’s principles extended across the plant and animals.
- In 2001, Willian Bateson named this discipline “Genetics”, and “Gene” the unit of this discipline is the factor that was inherited.
The Genetics studies the difference between the individuals. If there is a difference it is transmitted to the next generation by sexual reproduction, or other process. In brief genetics studies the descendance across diverse individuals through at least two successive generations.
The mechanism of heredity depends on probabilities, but only some statistical concepts are needed.
The research of Morgan on the fly proved that the genes were on the chromosomes.
But it was still unknown what genes were made up of, what was their molecular structure, and biologists debates the genetic material was DNA or proteins.
In 1952, Alfred Hershey and Martha Chase at Cold Spring Harbor Laboratory ingeniously used viruses (proteins and DNA inside) and proved by a radioactive experience that the genetic material is the DNA.
After many research, James Watson and Francis Crick at the University of Cambridge determined that DNA was a double helix, and the structure is two strands wrapped around each other.
DNA (DeoxyriboNucleic Acid) is a very long polymer made up of four different nucleotides (Adenine (A), Guanine (G), Cytosine (C), and Thymine (T).). A always bind to T, and G always to C.
These long double helix strands make up chromosomes, chromosomes divided into thousand of unit to form genes.
Molecular biologists spent the 1950s and 1960s using the double helix structure of DNA elucidate the mechanism of genetic replication and function.
Gene Role in Organisms
- DNA is made into RNA
- RNA specifies the structure of a specific protein
- DNA is transcribed into mRNA (RNA messenger) by the enzyme RNA polymerase (specific DNA sequences ensure that RNA polymerase transcribes certain genes only in the correct cell type at the proper time.)
- The mRNA serves for the protein synthesis by using the ribosomes and tRNAs.
Role of Molecular Genetic
- Learning what is the role of DNA in determining the regulation of gene expression.
- DNA replication in cells.
- Determination of the complete DNA Sequence of several organisms.
- Determination of the sequence of proteins.
- Trying to understand how the sequence of a proteins determines its function.
- Study of mutations that results of the errors during the replication of DNA.