Genetics

The science of heredity and variations in living organisms is termed as genetics. The quality of crop plants and animals can be improved a lot through selective breeding. The famous scientist Gregor, Mindal is responsible for the origin of the modern science of genetics which seeks to understand the process of inheritance. Even without any prior knowledge about the physical basis for hereditary Mindal was able to observe and understand that organisms inherit traits via discrete units of inheritance which are now termed as genes. Genes correspond to regions within DNA. 

DNA molecule is in turn composed of a chain of two different types of nucleotides. The genetic information that organisms inherit is mainly due to the sequence of this nucleotides. DNA takes place in a dual stranded structure with nucleotides on each strand complementary to each other. Each strand in turn, can be considered as a template for the creation of a new partner strand thereby providing the essential physical process for creating reproduction of genes that can be innate. The cells translate the series of nucleotides in a gene revolve to the creation of a series of amino acids and thereby creating proteins. Hence the order of amino acids in a protein should correspond to the order of nucleotides in the gene which forms the genetic cord. The folding of the protein into a three dimensional shade and thereby its function is determined by the amino acids existing within the same. All the functions required for the thriving of cells are carried out by the proteins. The shape and function of proteins amino acids are controlled by the DNA and as a result a change in the DNA can change the proteins, amino acids which can have a dramatic effect in the cell and on the organism as a whole. Genetics plays a crucial role as to the appearance and the behavior of organisms. But ultimate outcome is as a result of the combination of genetics with what an organism experiences. For example, an organism’s size is determined by the genes and the nutrition and other conditions the organism experience after the inception also has a considerable effect on the size of the organism.

Deoxyribonucleic acid forms the molecular basis for genes. Adenine, Guanine, Cytosine and Thymine are the four major types of nucleotides that are responsible for the composition of DNA. It is in the sequence of these nucleotides that the genetic information prevails. Genes exist as stretches of sequence along with DNA chain. The only exception to this basic rule can be seen in viruses where viruses have the ability to use the very similar RNA molecule as their genetic material. Researchers are able to determine the sequence of nucleotides in the DNA fragments due to DNA sequencing. Frederick Sanger and his coworkers can ne considered as architects of chain termination sequencing which is routinely used to sequence DNA fragments. This DNA sequencing is being used by researchers to investigate the molecular series connected with various human syndromes.

Following are the free online genetics ebooks previews and pdf files available in web.

1. Genetics: analysis of genes and genomes By Daniel L. Hartl, Elizabeth W. Jones
2. Genetics By Rebecca L. Johnson 
3. Genetics: science, ethics, and public policy : a reader By Thomas Anthony Shannon
4. Genetics: unlocking the secrets of life By Nathan Aaseng
5. Genetics By D. J. Cove 
6. Human molecular genetics 3 By T. Strachan, Andrew P. Read
7. Genetics By G. Archunan 
8. Statistics in molecular biology and genetics By Françoise Seillier-Moiseiwitsch 
9. Genetics By Drs. Scott Poethig, Ingrid Waldron, and. Jennifer Doherty 
10. Primer on Molecular Genetics 
11. Bacterial Genetics 
12. Cancer Genetics 
13. Genetics and Breeding of Groundnut 
14. Evolutionary genetics: the Drosophila model 
15. The New Genetics