Answer:
The correct answer is b The regulator gene falls off the operator and the structural genes get transcribed.
Explanation:
Tryptophan operon contain3 regulatory genes and 5 structural genes.when adequate amount of tryptophan is present at that time the tryptophan binds to the repressor molecule encoded by tryp R gene.Thus Tryptophan act as co repressor .The repressor molecule bound to tryptophan interacts with operator region resulting in blocking the expression of structural genes.
But when tryptophan is absent at that time repressor molecule cannot function.As a result the repressor molecule fall off from the operator and structural genes get transcribed.
Answer:
Skin is the human body's largest organ.
Explanation:
Body organs aren't all internal like the brain or the heart. There's one we wear on the outside. Skin is our largest organ—adults carry some 8 pounds (3.6 kilograms) and 22 square feet (2 square meters) of it.
A mule is a hybrid between a horse and a donkey (a male horse and a female donkey). Mules cannot produce offspring so it is under Hybrid Sterility, which falls under Letter D: a postzygotic barrier.
A postzygotic barrier diminishes the ability to reproduce of hybrid offsprings.
<span>A theory is replaced rather than revised when the fundamental assertions or ideas behind the theory are proved to be incorrect. When a theory is replaced it is called superceded or obsolete (but only if it was once accepted by the scientific community at large - fringe theories remain fringe theories). One example is Lamarckism in evolutionary theory which was succeeded by Mendel’s ideas of genetics and Darwin’s theory of evolution.</span>
Radiation, the sun warms us by the rays