There are three classifications of lactose intolerance. The two most common are environmentally induced, the third is a result of genetics.
1. Primary lactose intolerance. Environmentally induced when weaning a child in non-dairy consuming societies. This is found in many Asian and African cultures, where industrialized and commercial dairy products are uncommon.
2. Secondary lactose intolerance. Environmentally induced, resulting from certain gastrointestinal diseases, including exposure tointestinal parasites such as Giardia lamblia. In such cases the production of lactase may be permanently disrupted. A very common cause of temporary lactose intolerance is gastroenteritis, particularly when the gastroenteritis is caused by rotavirus. Another form of temporary lactose intolerance is lactose overload in infants.
3. Congenital lactase deficiency. A genetic disorder which prevents enzymatic production of lactase. Present at birth, and diagnosed in early infancy.
In the lac operon model, lactose acts as in inducer molecule. In the presence of lactose, the molecule binds to the repressor protein. This repressor-lactose complex is unable to bind to the promoter. When the promoter is not occupied, RNA pol - II binds to it and begins transcribing the structural genes located downstream. Thus, the lac operon is turned on in the presence of lactose.
Environmental factor or ecological factor or ecofactor is any factor, abiotic or biotic, that influences living organisms.
Lactose is a disaccharide, made up of a bonded glucose and galactose.
religious intolerance
The environmental factor is excessive sun exposure.
If you can feel it, see it, hear it, taste it or smell it, it is an environmental factor. We tend to use the words "environmental factor" only for negative attributes, like loud noises or nasty smells. But anything that you can sense in the environment (which is everything around you) is an "environmental factor".
limiting factor
Religous intolerance of Hindus.
no
Yes.
Environmental Factor.
it is an environmental factor that causes a population to decrease.