Diener and Raymer in 1967 were the first to discover viroids when they were studying the spindle tuber disease in potatoes. They found that the... View Article
The F factor in the male cell may exist as a separate DNA molecule called plasmid or episome. In E.Coli the cell with F factor has 19 genes, and... View Article
There are many bacterial species that are capable of increasing the fertility of the soil by fixing nitrogen in the soil. These are called... View Article
It is an infectious disease occurring among the wild and domestic animals like sheep, cattle, goats, antelopes, etc. this may also occur among... View Article
An ulcer is a crater-like lesion or erosion in the membrane. These are developed in the alimentary canal, and it is called peptic ulcer. The... View Article
Many filaments are held up by the mucilage within the colony. Each filament is represented by an unbranched chain of cells. A chain of cells is... View Article
Heterocyst cells form a weak link and help in hormogonia formation. But in some species (for example - Nostoc commune), heterocyst produces... View Article
There is no sexual reproduction in Nostoc even though transduction and conjugation have been observed in a few unicellular cyanobacteria. But,... View Article
Many species of Agaricus are edible, and therefore they are cultivated. The most common species is Agaricus bisporus which is called white button... View Article
Mushrooms are the advanced members of a fungi group belonging to the class Basidiomycetes. They grow on dead and decaying matters like dung, old... View Article
Harmful effects of fungi - Spoilage of foodstuffs - many species of Penicillium, Aspergillus etc spoil foodstuffs like pickles, bread, milk... View Article
General characteristics of Bryophytes - The main plant body is a gametophytic thallus which is haploid in nature They are regarded as amphibians... View Article
The floral parts are inserted on the thalamus. In a few plants like roses, the thalamus grows further into a vegetative shoot after developing... View Article
In imbricate aestivation one of the petals in the corolla is internal, other external. The remaining petals show one margin in and another margin... View Article
The mode of arrangement of either sepals or petals on the thalamus is called aestivation. Valvate aestivation - when margins of the petals are... View Article
Microscope mother cells undergo meiosis to form spore tetrads. The microspores of pollen grains get separated from the tetrads. When these are... View Article
A fruit is defined as a fertilized and ripened ovary. The fruit wall is called the pericarp which can be thick, thin or even juicy and fleshy.... View Article
All the aggregate fruits are developed from multicarpellary apocarpous pistils. Hence, a cluster of fruitlets is produced from a single... View Article
Pome - is always developed from an inferior, multicarpellary and syncarpous ovary where the massive thalamus becomes an edible part. This... View Article