MOLECULAR BASIS OF INHERITANCE

MOLECULAR BASIS OF INHERITANCE

Genetics: Brach of biology which deals with the study of heredity and variation is called genetics.

 

Inheritance: Transmission of genetic characters from one generation to the next is called inheritance.

 

Nuclein: The acidic substance separated from the nucleus of the pus cell is called nuclein.

 

Variations: The difference that exists among the individual of the same species is called variation.

 

Virulent: Something which is able to cause infection is called virulent.

 

Non-virulent: Anything which is able to cause infection is called virulent.

 

Proteases: protein-digesting enzymes are called proteases.

 

RNAases: RNA-digesting enzyme are called RNAases.

 

DNAases: The DNA-digesting enzyme is called DNAases.

 

Bacteriophages: Virus infecting bacteria are called bacteriophage.

 

Virus: Acellular, microscopic infectious agent which are capable of multiplication only inside the host body are called a virus.

 

Nucleoid: The genetic material of prokaryote is called the nucleoid.

 

Histone: A simple protein which helps in the packaging of DNA in a prokaryote is called histone.

 

Non-Histone Chromosomal Proteins (NHC): The additional sets of proteins that contribute to the packaging of chromatin  at a higher level.

 

Heterochromatin: In eukaryotic cells, the genetically less active and a tightly packed form of DNA or condensed DNA is called heterochromatin.

 

Euchromatin: In eukaryotic cells, the genetically active and a loosely packed form of DNA is called euchromatin.

 

Nucleotide: It is the monomer of nucleic acid which is made up of pentose sugar, nitrogen base and phosphate group is called a nucleotide.

 

Replication: The process by which DNA makes its own exact copy or replica is called replication.

 

Heterocatalytic function: When DNA directs the synthesis of chemical molecules other than itself, then such functions of DNA are called heterocatalytic functions.

 

Autocatalytic function: When DNA directs the synthesis of DNA itself, then such function of DNA is called autocatalytic function. Eg. Replication.

 

Nucleoplasm: The ground substance present inside the nucleus is called nucleoplasm.

 

Point of Origin or Initiation point: The point on the DNA molecule from where the replication of DNA start is called a point of origin.

 

Replicon: The unit of DNA in which replication occurs is called replicon.

 

Tandem repeats: When a pattern of one or more nucleotides is repeated and the repetitions are adjacent to each other then it is called tandem repeats.

 

Restriction endonuclease: The restriction enzyme which specifically cut the DNA within the recognition sequence is called restriction endonuclease.

 

phosphodiester bond: The bond which is present between the 5^th and 3^rd carbon of the two successive nucleotides is called phosphodiester bond or the sugar-phosphate backbone of DNA is called phosphodiester bond.

 

RNA primer: The small RNA molecule which helps in the replication of DNA is called RNA primer.

 

Leading template: The template strand with free 3’end is called leading template.

 

Lagging template: The template strand with free 5’ end is called lagging template.

 

Okazaki fragments: The fragments of DNA formed on lagging strand of DNA during replication is called Okazaki fragments.

 

Equilibrium - density - gradient – centrifugation: The technique of separating a DNA sample using density gradient centrifugation performed with heavy metal salts like caesium chloride. 

 

Transcription: The process of formation of mRNA from DNA is called transcription.

 

Translation: The process of formation of protein from mRNA is called transcription.

 

Central dogma: The unidirectional flow of information from DNA to RNA to protein is referred to as central dogma.

 

Retroviruses or riboviruses: Viruses having RNA as their genetic material is called a retrovirus.

 

Reverse transcription: The process of formation of DNA from mRNA is called reverse transcription.

 

Codogen: The triplet present on the DNA is called codogen.

 

Codon: The triplet present on the mRNA is called a codon.

 

Anticodon: The triplet present on the tRNA is called the anticodon.

 

Mutation: Sudden change in the base sequence of DNA is called a mutation.

 

Transcription unit: The transcribed segment of DNA is called transcription unit.  It  consists  of a promotor, structural gene and a terminator.

 

Template strand: The DNA strand used in the synthesis of DNA is called template strand.

 

Sense strand: The DNA strand oriented in 5’ to 3’ direction is called sense strand.

 

Antisense strand: The DNA strand oriented in 3’ to 5’ direction is called antisense strand.

 

Introns: Non-coding regions of DNA are called introns.

 

Exons: The coding regions of the DNA are called exons.

hnRNA: The mRNA having both introns and exons are called hnRNA.(heterogeneous nuclear).

 

snRNA: The small nuclear RNA which helps in the splicing of the other RNA is called snRNA.

 

Cistron: The sequence of DNA which specifies specific polypeptide during protein synthesis is called cistron.

 

Muton: The small element of genetic material which can undergo mutation is called muton.

 

Recon: The element of genetic material which can undergo recombination is called recon.

 

Monocistronic: A single structural gene in a transcription unit is said to be monocistronic.

 

Polycistronic: A long segment of DNA having a set of various structural genes in one transcription unit is referred to as polycistronic.

 

Primary transcripts: The RNA transcribed from DNA are called primary transcripts.

 

Splicing : The process of removal of introns from an immature mRNA is called splicing.

 

Capping: The process of adding methylated guanosine triphosphate to the 5’ end of hnRNA is called capping.

 

Tailing: The process of adding polyadenylate residue at 3’end of hnRNA is called tailing.

  

Genetic Code: The means by which DNA and RNA carries the genetic information is called genetic code.

 

Cryptogram: The coding language of mRNA is called a cryptogram.

 

Homopolymer: A polymer made up of the same type of monomer is called a homopolymer.

 

Degeneracy of genetic code: The property of genetic code where a single amino acid is coded by more than one codon.

 

Non-ambiguous: The property of genetic code where a particular codon always code for the same amino acid.

 

Recombination: A process by which pieces of DNA are broken and recombined to produce new combinations of DNA is called recombination.

 

Point mutation: The mutation which affects only single nucleotide of the nucleic acid is called a point mutation.

 

Translocation: Movement of mRNA one step ahead along the ribosome is called translocation.

 

Start codon: Codon which initiates the process of protein synthesis is called start codon. Eg. AUG.

 

Stop codon: Codon which terminates the process of protein synthesis is called stop codon. Eg. UAA, UAG, UGA.

 

Untranslated regions (UTR): Sequences of m-RNA that are not translated are referred to as untranslated regions (UTR).

 

Operon: The cluster of gene performing the common function is called an operon.

 

Repressor protein: The protein which binds to the operator region of the operon is called repressor protein.

 

Regulatory gene: The gene which controls the operator gene in cooperation with an inducer present in the cytoplasm is called a regulatory gene.

 

Promoter gene: This gene precedes the operator gene. It is present adjacent to the operator gene and serves as a binding site for enzyme RNA polymerase.

 

Operator gene: It precedes the structural genes. This controls the functioning of structural genes.

 

Genomics: The study of genomes through analysis, sequencing and mapping of genes along with the study of their functions is called genomics.

 

Structural genomics: Genomics which involves mapping, sequencing and analysis of genome is called structural genomics.

 

Functional genomics: Genomics which deals with the study of functions of all gene sequences and their expression in an organism.

 

Genome: The total genetic constitution of an organism or the total number of genes present in a haploid set of the chromosome is called a genome.

 

Bioinformatics: The interdisciplinary field of science which combines the knowledge of biology, computer science, information technology, mathematics and statistics to analyze and interpret the biological data is called bioinformatics.

 

Biotechnology: Branch of biology which deals with the study of technique that involves the use of living micro-organisms or their secretion to develop products for the human welfare.

DNA Fingerprinting: The technique of identifying individual depending on their DNA print pattern is called DNA fingerprinting or DNA profiling.

 

Restriction Fragment Length Polymorphism (RFLP): The restriction enzymes cut the DNA  into small fragments having variable lengths. This phenomenon is called Restriction Fragment Length Polymorphism (RFLP).

 

Gel electrophoresis: The technique which is use to separate DNA fragments as per their length under the influence of electricity is called gel electrophoresis.

 

Southern blotting: The technique by which separated DNA fragments are transferred to a nylon membrane or a nitrocellulose filter paper by placing it over the gel and soaking them with filter paper overnight is called southern blotting.

 

DNA probe: The radioactive or fluorescently labelled DNA is called probe DNA.

 

Hybridization: A technique which is used to detect the particular sequence of DNA or RNA in a complex mixture of DNA or RNA molecule is called hybridization.

 

Autoradiography: The technique by which nitrocellulose filter paper is photographed on an X-ray film is called autoradiography.