Genes are units of heredity transferred from one generation to the next generation and are held to determine some characteristics of the offspring. The Word “ gene” was coined by Danish botanist Wilhelm Johnson in 1909. Gregor Mendel discovered that genes come in pairs and are inherited as distinct units. Genes are found on tiny structures called Chromosomes. Chromosomes are found inside the cells of our body. There is an important role of genes in determining physical traits. Information is carried by genes like whether a person has curly hairs or straight hairs, short legs or long legs. Most of these things are passed on from parents to their offspring.
Chromosomes are found in matching pairs or sets of two. There are hundreds or sometimes thousands of genes in just one chromosome. The chromosomes and genes are made up of DNA (deoxyribonucleic acid). Specific instructions are spelled out by DNA. DNA is just as a cookbook recipe for the synthesis of proteins in the cells. Most of the things in our body are made up of proteins such as bones, teeth, hairs, earlobes, blood, muscles. Hence, they are considered as building blocks of the body. Proteins are essential for our body to work properly, the growth of our body, and to stay healthy. It is estimated by scientists that each gene makes as many as 10 different proteins in the body. It goes up to 300,000 proteins.
Working of a gene can be explained with an example - Neera's mother has one gene for brown hair and one for red hair. She passed the brown hair gene to Neera. Neera's father has two genes for brown hair. Neera ended up with two genes for brown hair, one from each of her parents.
The information encoded in a gene is used in the synthesis of a functional product like protein, and the process is known as Gene expression. While in non-protein-coding genes such as tRNA or small nuclear RNA genes result in the formation of a functional RNA as a product. DNA is transcribed into RNA, and this transcribed RNA is then translated into proteins. This is known as central Dogma.
Structural genes are those genes that code for the amino acid sequences. There are two stages involved in the process of gene expression.
It is the process hatch that leads to the production of messenger RNA and the processing of the resulting mRNA molecule by using enzyme RNA polymerase.
It is the process in which mRNA is used to direct protein synthesis and also for the subsequent post-translational processing of the protein molecule.
Other forms of RNA that play a role in transcription can also be produced by some genes.
There are a number of components included in structural genes.
Exons: Amino acids are coded by exons and they thoroughly determine the amino acid sequence of the protein product. Exons are the portions of genes that are represented in the final mature mRNA molecule.
Introns: These portions of the genes do not code for amino acids and are spliced (removed) from the mRNA molecule before translation.
DNA is the genetic material of organisms and it is located in the nucleus and nucleoid.
The information necessary for development, function, ng, and reproduction is stored in DNA.
A monomer that contains DNA is the nucleotide which consists of three groups, pentose sugar, a nitrogenous base, and a phosphate group. Phosphate and nitrogenous base are attached to pentose sugar.
DNA is stable even in alkaline conditions.
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Gene is a specific nucleotide sequence.
Genes help to encode for an amino acid sequence of a specific protein.
Genes are made up of DNA but few may have RNA.
1. List Down a Few Differences Between a Gene and a Chromosome?
Genes are fragments of deoxyribonucleic acid.
Genes can not be seen under the microscope.
In every human cell, there are approximately 30,000 genes.
Either the Genes are composed of DNA or of the RNA.
Gene mutations are point mutations.
Genes are responsible for characters like the color of hairs, eyes.
Chromosomes are structures found within the cells and contain a person’s Gene.
Chromosomes can be seen under a microscope.
23 pairs of chromosomes are present in a human cell.
Chromosomes are made up of DNA and RNA.
Chromosomal mutations lead to abnormalities.
The sex chromosomes determine whether the child is a boy or a girl.
2. Give a Description of Ribonucleic Acid?
Ribonucleic acid or RNA is a complex compound of high molecular weight that helps in protein synthesis of a cell. In some viruses,s it replaces DNA as a carrier of genetic codes.
RNA is composed of ribose nucleotides attached by phosphodiesterase bonds and forms strands of varying lengths. Adenine, guanine, cytosine, and uracil are nitrogenous bases in RNA.
There are three types of RNA
mRNA or messenger RNA
tRNA or transfer RNA
rRNA or ribosomal RNA
These types of RNA carry out biochemical reactions performing regulatory functions.
RNA plays an important role in cellular processes and diseases. RNA can form complexes with ribonucleoproteins. RNA also acts as a biological catalyst.