Many So-Called Temperature-Sensitive Mutations Have Been Discovered in a Wide

Essay

Many so-called temperature-sensitive mutations have been discovered in a wide variety of organisms.These are proteins that are non-functional at higher temperatures,while,at lower temperatures (often just a few degrees lower),they function normally.For example,the coloration patterns in Siamese Cats arise from a temperature-sensitive mutation.An enzyme required for the synthesis of dark pigment is unable to function in areas close to the body where normal physiological temperatures prevail.However,at the tips of the ears,paws,the tip of the tail and other extremities where the temperature is slightly lower,the enzyme works correctly and dark pigment is produced.What is happening at the molecular level that explains this?