Genetics

Transposable Genetic Elements

Transposons were first discovered in corn (maize) during the 1940s and ’50s by American scientist Barbara McClintock, whose work won her the Nobel Prize for Physiology or Medicine in 1983. The colourful pattern on maize ears have an important scientific significance. Modern research have shown that the stripes and spots …

Read More »

DNA Replication in Eukaryotes: Linear Replication

DNA replication in eukaryotes is a complex and unique process involving many enzymes and thousands of ORI at a single time. Unlike the prokaryotic DNA, it involves a linear mode of replication. Why does linear DNA replication involve  multiple origins at a time? The large linear chromosomes in eukaryotic cell …

Read More »

Replication in Circular DNA: Theta Model

Following Meselson and Stahl’s work, investigators confirmed that other organisms also use semiconservative replication. There are, however, several different ways that semiconservative replication can take place, differing principally in the nature of the template DNA—whether it is linear or circular—and in the number of replication forks. Replicon and Origin of …

Read More »

Translation: mRNA to Protein

Translation takes place on ribosomes; indeed, ribosomes can be thought of as moving protein-synthesizing machines. A ribosome attaches near the 5′ end of an mRNA strand and moves toward the 3′ end, translating the codons as it goes. Synthesis begins at the amino end of the protein, and the protein …

Read More »

Post-transcriptional Modification

The process of transcription is very similar in prokaryotes and eukaryotes, but there are major differences in the relation between the transcript and the mRNA used for polypeptide synthesis in eukaryotes. In prokaryotes, the immediate product of transcription (the primary transcript) is mRNA; by contrast, the primary transcript (also called …

Read More »

Genetic Code

The four bases in DNA – A, T, G, and C are sufficient to specify the 20 amino acids in proteins because each codon is three bases in length. Each sequence of three adjacent bases in mRNA is a codon that specifies a particular amino acid (or chain termination). The …

Read More »

Transcription: The Mechanism of pre-mRNA Synthesis

Transcription is the synthesis of RNA molecule using one of the DNA strands as a template. It is the first step in the transfer of genetic information from genotype to phenotype. However, this process of transcription is a highly selective one i.e definite genes are transcribed only when their products …

Read More »

Difference Between: Part One (BOT: 308)

This part of the series named ‘Difference Between’ contains the difference between the following topics of the course ‘The Principles of Crop Improvement’. From syllabus Topic 1: Self incompatibility and cross incompatibility Protandry and Protogyny Self incompatibility (SI) and Coss incompatibility (CI) Gametophytic SI and Sporophytic SI Self incompatibility and …

Read More »

Cytpoplasmic Genetic Male Sterility

The male sterility which  is governed by both nuclear and cytoplasmic genes is known as Cytoplasmic Genetic Male Sterility or CGMS. While CMS is controlled by an extra-nuclear genome, nuclear gene may have the capability to restore fertility. When nuclear restoration of fertility genes (“Rf”) is available for a CMS …

Read More »