Genes are the fundamental units of heredity, composed of DNA, that carry the instructions for the development and functioning of living organisms. Understanding genes is crucial for unlocking the mysteries of inheritance, genetic variation, and the potential for advancements in medicine and biotechnology. This article aims to study in detail the structure and functions of genes, their role in heredity and variation, and the significance of genetics in understanding biological processes.
What are Genes?
- Genes are functional units of heredity as they are made of DNA. The chromosome is made of DNA containing many genes.
- Every gene comprises a particular set of instructions for a specific function or protein coding. Speaking in usual terms, genes are responsible for heredity.
- There are about 30.000 genes in each cell of the human body, but the DNA present in each gene comprises only 2 percent of the genome.
- Many studies have been conducted on the same, and they found the location of nearly 13000 genes on each of the chromosomes.
- William Bateson introduced the term genetics in 1905. Later, Danish botanist Wilhelm Johannes coined the term GENE in 1909. He named it Gene to symbolise heredity.
Characteristics Determined by Genes
- The human cell contains 23 pairs of chromosomes. The trait is one of the characteristics determined by one or more genes.
- Abnormal genes and genes formed due to new mutations also result in certain traits.
- Genes vary in size depending on the code or the protein they produce. All cells in the human body contain the same DNA.
- The difference between the cells occurs due to the different type of genes that are turned on and therefore produce a variety of proteins.
Functions of Genes
- Genes control the functions of DNA and RNA.
- Proteins are the most essential materials in the human body. They help build muscles, connect tissue, and skin and also produce enzymes.
- These enzymes are essential in conducting various chemical processes and reactions within the body.
- Therefore, protein synthesis is responsible for all body activities and is mainly controlled by genes.
- Genes consist of a particular set of instructions or specific functions. For example, the globin gene was instructed to produce haemoglobin, a protein that helps carry oxygen in the blood.
What are Genetics?
- Genetics is the study of genes and tries to explain what they are and how they work.
- Genes are how living organisms inherit features or traits from their ancestors for example, children usually look like their parents because they have inherited their parents’ genes.
- Genetics tries to identify which traits are inherited and explains how these traits are passed from generation to generation.
- Molecular Biology is the field of biology that studies the composition, structure, and interactions of cellular molecules, such as nucleic acids and proteins, which carry out the biological processes essential for cell functions and maintenance.
- The European Federation of Biotechnology defines Biotechnology as “The integration of natural science and organisms, cells, parts thereof, and molecular analogues for products and services”.
- Biotechnology deals with techniques for using live organisms or enzymes from organisms to produce products and processes useful to humans. Some of the techniques under Biotechnology include in-vitro fertilisation leading to a ‘test-tube’ baby, synthesising a gene and using it, developing a DNA vaccine, or correcting a defective gene.
Functions of Genetics
- Genetics is a branch of biology that studies heredity and its biological processes, genes, genomes, cell cycles, heredity, inheriting genes, and much more.
- Genetics is the exploration of the working and major codes of variation and heredity.
- The foundation of heredity is inheritance, which is defined as the procedure by which characteristics are passed down from one generation to the next.
- Gregor Johann Mendel is known as the “Father of Modern Genetics” for his discoveries on the basic principles of heredity.
- Variation, as the name suggests, is the dissimilarity between children and their parentages.
- It can be determined to keep in view the behaviouristic, cytological, physiological, and morphological characteristics of individuals fitting into similar species. Some of the significant reasons for variation are:
- Genetic/Chromosomal rearrangement.
- Mutated genes due to the influence of the ecosystem.
- Crossing over.
- gene silencing
| Deoxyribonucleic Acid (DNA) is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (which is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (which is called mitochondrial DNA or mtDNA). |
| Ribonucleic Acid (RNA) is one of the three major biological macromolecules essential for all known life forms (along with DNA and proteins). RNA is important in regulating cellular processes–from cell division, differentiation and growth to cell ageing and death. Phenotype refers to all the observable characteristics of an organism that result from the interaction of its genotype (total genetic inheritance) with the environment. Observable characteristics include behaviour, biochemical properties, colour, shape, and size. Chromosome: DNA is tightly coiled to make a thread-like structure called a Chromosome. Human beings have 46 chromosomes (23 from each parent). The chromosome is the microscopic thread-like part of the cell that carries hereditary information in the form of genes. Nucleotide: A nucleotide is an organic molecule that is the building block of DNA and RNA. Genes: A gene is a ‘specific’ section of DNA. It makes RNA (transcription) or protein (translation). Gene pool: A gene pool collects different genes within an interbreeding population. Enzymes: Biological molecules, usually proteins responsible for thousands of metabolic processes essential to life. |
Comparison of DNA and RNA
DNA and RNA are used to store genetic information, so there are clear differences between them. The following table summarises the key points:
| Comparison of DNA and RNA | ||
|---|---|---|
| Comparison | DNA | RNA |
| Function | Long-term storage of genetic information; transmission of genetic information to make other cells and new organisms. | Used to transfer the genetic code from the nucleus to the ribosomes to make proteins. RNA is used to transmit genetic information in some organisms |
| Structural Features | B-form double helix. DNA is a double-stranded molecule consisting of a long chain of nucleotides. | A-form helix. RNA usually is a single-strand helix consisting of shorter chains of nucleotides. |
| Composition of Bases and Sugars | Deoxyribose sugar-phosphate backbone Adenine, Guanine, Cytosine, and Thymine bases | Ribose sugar; Phosphate backbone; Adenine, Guanine, Cytosine, Uracil bases |
| Propagation | DNA is self-replicating | RNA is synthesised from DNA on an as-needed basis. |
| Base Pairing | AT (Adenine-Thymine); GC (Guanine-Cytosine) | AU (Adenine-Uracil); GC (Guanine-Cytosine) |
| Ultraviolet Damage | DNA is susceptible to UV damage. | Compared with DNA, RNA is relatively resistant to UV damage. |
Conclusion
In conclusion, genes are integral to the biological processes defining living organisms, influencing everything from physical traits to disease susceptibility. The study of genetics sheds light on how traits are inherited and opens pathways for advancements in medicine, agriculture, and biotechnology. As research continues to uncover the intricacies of genetic information, the potential for innovative applications in improving health outcomes and enhancing agricultural productivity becomes increasingly significant. Understanding genes and their functions will remain a cornerstone of scientific inquiry, driving the quest to harness the power of life itself.
FAQs
What are genes ?
Genes are units of heredity made of DNA that carry instructions for building proteins, essential for life functions. They determine traits like eye color and height, passing from parents to offspring. Genes influence health, behavior, and evolution, playing a crucial role in genetics and biological diversity.
What are the 4 types of genes?
– Structural genes – Code for proteins that build body structures and enzymes.
– Regulatory genes – Control gene expression by turning other genes on or off.
– Housekeeping genes – Maintain essential cellular functions.
– Proto-oncogenes – Regulate cell growth, but mutations can cause cancer.
What is the concept of genes?
The fundamental unit of inheritance is thought to be the gene. The information required to specify physical and biological features is contained in genes, which are passed down from parents to children. The majority of genes produce certain proteins or protein fragments with a variety of bodily activities.
What is a genome ?
A genome is the complete set of an organism’s DNA, including all its genes and non-coding sequences. It contains instructions for growth, development, and functioning. The human genome has about 3 billion DNA base pairs. Genomics studies genomes to understand heredity, evolution, and disease mechanisms for medical advancements.
Where are genes located?
Genes are located on chromosomes inside the nucleus of a cell. Chromosomes are made of DNA, which carries genetic information. Some genes are also found in mitochondria, known as mitochondrial DNA. These genes control traits, cellular functions, and heredity, passing from parents to offspring through reproduction.
What is gene mutation?
A gene mutation is a permanent change in the DNA sequence of a gene. It can occur due to errors in DNA replication, environmental factors, or inherited conditions. Mutations may be harmless, beneficial, or harmful, leading to genetic disorders, cancer, or evolution by introducing new traits in organisms.
