Lactase refers to an enzyme that can dissociate lactose sugar into glucose and galactose. This enzyme plays an important role in the digestion of milk that comprises high lactose sugar. In case, if a mutation occurs in the gene codon of lactase, then two possibilities can take place. These are as follows:
1. Loss of mutation: In this case, the person becomes lactose intolerant because of mutation in lactase gene codon. Due to this, there is low mRNA expression and thus low production of the enzyme lactase. This is also known as lactase non-persistent phenotype.
2. Gain in mutation: In this case, the person gain an increase in mRNA expression of the lactase gene, thus more production of lactase takes place than usual. This kind of individual exhibits lactase persistent phenotype.
For the environmental risk, it is much better to prevent pollution than to deal with it after it has already been made. When you deal with the pollution, it is hard to say that you can eliminate completely. So, prevention is the first strategy.
Answer:
I would say B
Explanation:
Because atural selection is the mechanism for how evolution occurs over time. Basically, natural selection says that individuals within a population of a species that have favorable adaptations for their environment will live long enough to reproduce and pass down those desirable traits to their offspring.
Atoms are the most basic units
Elements are specific types of atoms
Compounds are composed of more than one type of element and are held together by chemical bonds
Is this a serious question ? loool