What is inside a chromosome?

We have already studied the definitions of chromosome, genome, and DNA in the previous blogs. Now, let us have a look on what is there inside the chromosome.

Each human cell contains 46 chromosomes except eggs and sperms, and which is present inside the nucleus. 23 chromosomes come from the father and other 23 chromosomes from the mother. The DNA associated with histone proteins are wrapped inside the structure called chromosome and it is replicated in the time of cell division. These chromosomes are visible under microscope only during the cell division! 

Why the DNA packaging is so important? Chromosome has plethora of genetic information which stored in DNA. If the DNA present in a cell uncoil, it comes to six feet long!

 Related Terms:

• Histone - These are the proteins which helps the DNA packaging inside the cell's nucleus. Moreover, which helps the DNA to condenses in chromatin. These proteins are rich in lysine and arginine. 
• Nucleosome - It is the repeating unit of chromatin. DNA along with histone proteins form nucleosome. The core histones such as H3, H4, H2A and H2B form H3-H4 tetramer and H2A-H2B dimer. The negatively charged DNA wraps around the positively charged histone octamer. As an outcome, the nucleosomes are stabilized. 
• Chromatin - Nucleosomes packed together to form chromatin. The chromatin loops fold around each other to form chromosome.
• Centromere - The structure which holds the sister chromatids together. Each chromosome has two p and q arms which held together by centromere.
• Telomeres - The repetitive sections of DNA present at the end of each eukaryotic chromosome, which plays a vital role in chromosome replication and maintenance. Telomeres protect the chromosome from becoming impaired. During each cell division, some part of telomeres may lose in some of the cells. If the telomeres completely gone, the cell dies.

References:

• The Jackson Laboratory. (n.d.). Minute to Understanding: What is a chromosome? https://www.jax.org/news-and-insights/minute-to-understanding/what-is-a-chromosome.
• What is a chromosome? (2016, January 25). Yourgenome. https://www.yourgenome.org/facts/what-is-a-chromosome.
• NHGRI. (2019, March 9). Chromosomes Fact Sheet. Genome.Gov. https://www.genome.gov/about-genomics/fact-sheets/Chromosomes-Fact-Sheet.

Thank you!

Genetics and its divisions

Genetics

Genetics is the study of genes and heredity. It also deals with how the traits or certain characteristics are being passed to offsprings from parents. Gene is the basic unit of heredity, and it is the part of DNA which has the information for protein synthesis. The entire set of genes in an organism is called genome. The genome is present in the nucleus in the case of human, animal and plant cell.

Genetics plays a major role in disease diagnosis, personalized treatment for diseases and to identify the likelihood of getting a particular ailment. This all can be understood based on the genetic information. Any changes in the gene can prevent the certain protein synthesis which affect the specific functions. Genome sequencing technology is being used to identify the changes in the gene, and this information can be used for the betterment of human life.

Divisions

Primarily, there are 3 following subdivisions for genetics.

• Transmission genetics (Classical genetics)
• Molecular genetics
• Population genetics

Transmission genetics deals with how the genes are being transferred from one generation to other generation. It mainly focuses on an individual's genetic make up and how it inherits to the following generation. Molecular genetics emphasis on the structure and function of gene. It includes processes such as replication, transcription, translation and gene regulation. Whereas, population genetics studies the genetic makeup of individual members of the same species. It mainly deals with the evolution that is how the genetic make is being changed over time and space.

Other branches of genetics

• Microbial genetics - The study of genetics of microorganisms such as bacteria, viruses, unicellular plants and animals
• Immunogenetics - The study of the effect of genes on immune response
• Behavioral genetics - The study of the impact of genetic composition on one's behavior
• Human genetics - The study of human hereditary processes and inheritance
• Animal genetics - The study of genes and heredity in animals
• Plant genetics - The study of genes and heredity in plants
• Viral genetics - The study of genetics of viruses
• Cytogenetics - The microscopic study of chromosomes to understand the changes in the chromosome like extra or missing chromosome, broken etc. which lead to genetic diseases
• Clinical genetics - The study of causes and inheritance of genetic disorders

References

• Winchester, A. (2020, May 15). genetics. Encyclopedia Britannica. https://www.britannica.com/science/genetics.
• Branches and Importance of Genetics, study&Score. (n.d.). STUDYANDSCORE. https://www.studyandscore.com/studymaterial-detail/branches-of-genetics-importance-of-genetics
• Genetics. (2000). NIGMS. https://www.nigms.nih.gov/education/fact-sheets/Pages/genetics.aspx.
• Genetics, A Conceptual Approch by Benjamin.A.Pierce

               

                Hope you all like the information!

T             Thank you!😊