"Housekeeping genes" in bacteria are commonly expressed constitutively, but not all of these genes are expressed at the same lev
el (the same number of molecules per cell). The primary mechanism responsible for variations in the level of constitutive enzymes from different genes is that:
Housekeeping genes may be defined as the genes that are constitutive genes important for the cellular functioning of the organism. The expression of housekeeping gene may or may not vary.
Some housekeeping genes are not expressed at same level because the housekeeping genes also have different promoters. The different promoters have different affinity to interact with the holoenzyme of RNA polymerase.
The sponge-like structure, as well as the high salt content of water and the <span>ease of contaminating water contribute to the environmental stress on a coral reef.
The cell theory developed most quickly due to the invention of the microscope. Robert Hooke was the first scientist who saw cells in cork. After this discovery, a wide numbered of researches were made and cell theory was developed. The basic cell theory explained that how every living thing was made up of cells. After this, a lot of additions have been made in the cell theory and today the cell theory is known to have five basic postulates.
