Mindblown: a blog about philosophy.

A trait or end product (e.g., in a grain-produced crop) that requires simultaneous expression of more than one gene. For example, the level of protein produced in soybeans is controlled by five genes. Inheritance of an attribute whose expression is controlled by many genes or pairs. A trait that is expressed as a result of…

An enzyme (e.g., present in tomatoes) that starts the breakdown (softening) of the fruit tissue. Recent advances make it possible to significantly delay the softening (i.e., spoilage) process by reducing the production of polygalacturonase through genetic engineering of the plant. In 1 986, William Hiatt of the American company Calgene discovered the gene for polygalacturonase,…

Because a given pathogen generally has several antigenic sites on its surface, the B lymphocytes (activated by helper T cells in response to a pathogen invading the body) synthesize several (subtly different) antibodies against that pathogen. And since the antibodies are made by different cells the response is known as poly(many)clonal.    

A mixture of antibody molecules (that are specific for a given antigen) that has been purified from an immunized (to that given antigen) animal’s blood. Such antibodies are polyclonal in that they are the products of many different populations of antibody-producing cells (within the animal’s body). Hence they differ somewhat in their precise specificity and…

Coding regions representing more than one gene in mRNA (i.e., they code for two or more polypeptide chains). Many mRNA molecules in procaryotes are polycistronic.  

The addition of a sequence of polyadenylic acid to the 3′ end of a eucaryotic mRNA after its transcription (post-transcriptional). The addition of a sequence of polyadenylic acid to the 5′ end of a eukaryotic RNA after its transcription.  

A form of chromatography in which molecules are separated on the basis of size and charge. The stationary phase (the polyacrylamide gel) is a polymerized version of acrylamide monomers. The gel looks and feels like Jello™. On a molecular basis it consists of an intertwined and cross-linked mesh of polyacrylamide strings. As can be imaged,…

A “sieving” gel, that is used in electrophoresis.  

Having to do with the one way or unidirectional ity of gene transcription in an operon unit. That is, the region near the operator is always transcribed before the more distant regions. By analogy, transcription begins at the left end of an operon unit and proceeds (reads, transcribes) toward the right end of the operon…

The degree to which an atom or molecule bears an electrical charge or a partial electrical charge. In general, the more polar (i.e., separation or partial separation of charge) a molecule is, the more hydrophilic (“water loving”) it is. Polarity results from an uneven distribution of electrons between the atoms comprising a molecule.