Are viruses living organisms?
By: Omar Salvador
Viruses constitute a large group of infectious organisms which are much smaller than bacteria. They possess a common characteristic - that of being obligate intracellular parasites for the cells of the hosts they select. This means that viruses can grow and reproduce only if they...
By: Jamie Rider
Definition of Yeast Artificial Chromosome (YAC) Libraries Yeast Artificial Chromosome libraries are made by the systemic insertion of series of large human DNA fragments into a yeast strain capable of replicating the DNA insert truly, through multiple generations. The resulting organisms, when maintained under tightly...
Introduction to chewing lice: Order Mallophaga
By: M E Skeel
Parasitic lice are divided into two major groups according to their method of feeding. Here, we are dealing with the chewing lice. Some authorities consider them a full order, the Mallophaga, while others call the Mallophaga a suborder of the order Phthiraptera. Either way, they...
By: M E Skeel
Springtails are small, soil-dwelling animals that look and act like insects but which some scientists separate from the true insects. Springtails have six legs and are therefore classed in the superclass Hexapoda. They used to be an order of the arthropod class Insecta but are...
Are viruses living organisms?
By: M E Skeel
If the definition of life is that it must be made of cells, then the answer is no, because viruses are not surrounded by a cellular membrane. However, perhaps it is time to revisit the definition of life, because viruses can certainly act like living...
Introduction to sucking lice: Order Anoplura
By: M E Skeel
Lice are divided into three groups: sucking lice, elephant lice and chewing lice. Lice with sucking mouthparts belong to the order Anoplura (although some taxonomists call this a suborder in the order Pthiraptera). Sucking lice are parasites of mammals. There are about 500 species of...
Migratory patterns of the Gray whale
By: Jose Juan Gutierrez
Gray whales spend the summer season feeding in the cold waters of the north, and then in October, as the northern ice starts to form southward, they begin to move in small groups and along the Western coast of Canada and the United States, until...
Preparation of tissue for light microscopy
By: Frank Kero
The scientific community has long used methods of descriptive observation as a means of reducing the mysteries of nature into discrete and finite systems. Analogous to the utility of telescopes in describing spectral features of the night sky, optical microscopy seeks to mitigate the limitations...
By: Dr Pandula Siribaddana
Artificial chromosomes are one of the major determinants of the successes made in the field of cloning and yeast artificial chromosomes (YAC) are one of its many forms. Among the other forms of artificial chromosomes, bacterial artificial chromosomes, phage artificial chromosomes and p1-derived artificial chromosomes...
Introduction to fleas: Order Siphonaptera
By: M E Skeel
Fleas don't have a very good image to the general public. They are associated with dogs, rats, unclean conditions and disease. But one has to admit that they are amazing little survivors. They have adapted themselves to an ectoparasitic lifestyle that has been highly successful...

 

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