Discussion on the Molecular Basis of Inheritance Class 12 NCERT Solutions:
In this chapter for Class 12, we will learn about genes and genetics in detail. Our genes determine much of our biological constitution and determine our chances of developing certain diseases and disorders. It is important to learn about them so as to better understand the human body and by extension, ourselves.
This chapter navigates many subtopics and questions relating to genes and how important they play in heredity and inheritance. The phenomenon of heredity is central to biology, and inheritance is how those genes are passed from generation to generation. We understand how genes influence our traits and characteristics by learning about them.
We’ll also take a closer look at the RNA world or Replication. Transcription and the genetic code are other topics that are also very important to understand and will be explored in this chapter.
Finally, this chapter will also talk about the Human Genome Project. This massive project was undertaken to identify, map, and sequence all of the genes that comprise the human body. We also examine DNA fingerprinting and its importance in forensics and how it aids criminal investigations.
In the 19th century, biologists discovered that the material responsible for heredity was passed from the parent to the child. This theory was based on the principle that organisms inherit their traits from their parents.
In 1869, German scientist Friedrich Miescher discovered a substance in the cells of animals and humans that contained genetic information. It was called ribonucleic acid (RNA) as it was found in the cellular fluid (the fluid containing water and proteins) called nuclein. Miescher was not aware of what it was or what it did, but he knew for sure that it was found only in the cells of living things.
The story of the discovery of genes is a classic example of scientific discovery. In 1869, a German scientist called Julius Wagner-Jauregg treated an Austrian Archduke with a mysterious illness and discovered that he could cure syphilis by injecting his patients with the blood of animals.
The following year, another German scientist, Friedrich Miescher, discovered the material that Wagner-Jauregg had used in his syphilis treatment – a material that is now known as DNA. It took 70 years before scientists discovered how DNA was copied and passed onto offspring.
The search for genetic material that makes us who we are has fascinated scientists for ages. In the 19th century, Charles Darwin also acknowledged the fundamental importance of genetics and the inheritance of acquired characters. The 19th-century researchers also found that cell materials such as chlorophyll and proteins were made of tiny building blocks called amines, purines, and pyrimidines.
The search for the material responsible for the transmission of genetic information is one of the greatest scientific adventures of the 20th century.