Genetics/Molecular

Transposons

Transposons

Transposons Transposons are a kind of mobile DNA  (deoxyribonucleic acid) of 2000–20,000 bp. They can transfer DNA (deoxyribonucleic acid) from one site of the bacterial chromosome to another site or to a plasmid. The theroy of transposons or jumping genes was first given by Barbara McClintock, a geneticist working in the field of maize genetics.  The mode …

Transposons Read More »

The lac operon is inducible

lac operon

lac operon An example that has been studied in great depth concerns the enzyme β-galactosidase, used by E. coli to convert the disaccharide lactose into its sugars constituent: Lactose −−−−−−−−→ Glucose + Galactoseβ-galactosidase β-galactosidase has been more studied as part of the lac operon of E. coli. This is made up of three structural genes designated Z, Y and A, …

lac operon Read More »

Meiosis

Meiosis

Meiosis Meiosis is the general name given to two successive nuclear divisions called meiosis I and meiosis II. Meiosis takes place in special diploid cells called meiocytes. Because of the two successive divisions, each meiocyte cell gives rise to four cells, 1 cell →2 cells →4 cells. The four cells are called products of meiosis. …

Meiosis Read More »

mitosis

Mitosis

Mitosis Introduction When cells divide, the chromosomes must also make copies of themselves (replicate) to maintain the appropriate chromosome number in the cells. In eukaryotes, the chromosomes replicate in two main types of nuclear divisions, called mitosis and meiosis. These two types of divisions are quite different and have different functions, some of the molecular …

Mitosis Read More »