Answer:
In order to clone the sequence of the gene for one of the human crystallins found in the eye, there is a need for the application of polymerase chain reaction. In the process, the particular sequence of gene is denatured and then replicated various times to generate various clones of the gene sequence.
By producing various copies of the gene sequence for the human crystallin, that is, desirable, a scientist can examine various distinct characteristics of the protein as there is always more to examine with.
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.
Answer:
B
Explanation:
A pit is a tiny depression which is found on the surface of the tooth.
Fissures are the grooves that occur naturally on the biting surfaces of teeth.
Thus, pits and fissures are located on the lingual surfaces of the maximillary first molars because of the lingual fissures on the max molars.
