Effects of Gene Mutations

Introduction:  

Genes are the functional units of heredity. Chromosomes are made of DNA that contains genes.  

Explanation: 

Genes are the functional units of heredity; they are made up of DNA. The chromosome is made of DNA containing many genes. Each gene comprises a particular set of instructions for a particular function or protein-coding. 

Discovery of genes – William Bateson introduced the term genetics in the year 1905. Later, Wilhelm Johannes was the first one who coined the term ‘gene’ in the year 1909. He was a Danish botanist. He named it Gene to symbolize hereditary. 

What are genes? 

Genes contain DNA. The DNA has a specific code for protein synthesis. Genes can vary in size. The complete set of chromosomes is called a Genome. The number of genes in a Genome is different in different species. For example, a human genome comprises 22000 – 25000 Genes. 

Organisms are divided into two types—Eukaryotic and Prokaryotic. Eukaryotic organisms include animals, plants, and certain fungi that have a definite nucleus in the cell membrane, thus genes are present in the nucleus of the cell. In prokaryotic organisms like certain bacteria where the nucleus is not present, the genes are present in a single chromosome that floats freely in the cytoplasm. Each individual is inherited 2 copies of genes one from each parent 

Structure of genes 

The DNA looks like a twisted ladder that is composed of nucleotides. The sides of these ladders are made up of sugars and phosphates and the horizontal steps of this ladder which are called the rungs made up of pairs of nitrogenous bases. The bases are named Adenine (A), Guanine (G), Thymine (T), and Cytosine (C). 

Functions of genes 

• Transcription is the process  when the information of DNA is copied into a new molecule of messenger RNA (mRNA) 
• Translation- The mRNA is the responsible factor to make sure which amino acids need to link together. 
• Gene Expression- The expression of genes depends on various factors that include the age and sex of the individual, the type of tissue of the organ and what chemical substance it releases, etc.  
• The mutation is the change in the DNA sequence.  
• DNA replication is the process that occurs in all living organisms to copy their DNA and pass their progeny. This ensures the continuity of the species.