Porella
Systematic Position Division: Bryophyta Class : Hepaticopsida Order : Jungermanniales Family : Porallaceae Genus : Porella Occurrence: Most species of Porella are distributed in tropical to temperate regions. It grows on moist rocks, on the shaded sides of tree trunks. It forms dense mats closely covering the ground. Some are […]
General characters
The mosses and moss alies belong to a single division the Bryophyta. This division includes the most primitive of the green land plants. Bryophytes are structurally simple in both morphology and anatomy. Bryophytes are the most simplest and most primitive land plants Name bryophyte is derived from two words; ‘Bryon’ = moss; ‘phyton’ = plant. At […]
Statistics
Agaricus
This is a large genus of fungi often synonymized with the term ‘mushrooms’, distributed mainly in temperate regions. Agaricus spp. are saprotrophs, growing in pastures and woodland litter. The mycelium is perennial and some species and some species, e.g. A. arvensis (horse mushroom), A. xanthodermus (yellow stainer) and A. tabularis may fruit in rings. From measurements […]
Constructing a Library of Genes
Gene libraries are used to find new genes, to sequence entire genomes, and to compare genes from different organisms. Gene libraries are made when the entire DNA from one particular organism is digested into fragments using restriction enzymes, and then each of the fragments is cloned into a vector and transformed into an appropriate host. […]
Yeast Bread-making
The principle behind the leavening of bread dough by baker’s yeast is the same as in brewing, i.e. the anaerobic metabolism of glucose and other reducing sugars via pyruvic acid into ethanol and CO2. The difference is that the released CO2 is the important product in breadmaking because it is responsible for the texture of […]
Ascomycota Fruit Bodies
Types of fruit body: There are number of fruit bodies in Ascomycota. In yeasts and related fungi the asci are not enclosed by hyphae, but in most ascomycetes they are surrounded by hyphae to form an ascocarp or ascoma. An old term for ascus is theca (Gr. theca=a case), and although this word is not now in general […]
Knockout Mice for Medical Research
Transgenic animals, mostly mice, are of great value in the genetic analysis of inherited diseases and cancer. Here we are interested not so much in adding a cloned transgene as in discovering the function of genes already present. The general approach is to inactivate, or “knock out,” the gene of interest and then ask what […]
Transgenic Animals
NEW AND IMPROVED ANIMALS For thousands of years people have improved crop plants and domestic animals by selective breeding, mostly at a trial-and-error level. Woollier sheep and smarter sheep dogs have both been improved through many generations of selective breeding. Obviously, the more we know about genetics, the faster and more effectively we can improve […]
BT Toxin and Butterflies
Another issue with transgenic plants is the effect they may have on nontarget organisms , that is, any plants or animals inadvertently exposed to the transgenic crop or insecticide. An article in the journal Nature suggested that Monarch butterflies were killed by eating pollen from corn carrying the Bt gene. The study alarmed the science […]