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.
A virus attaches to a specific receptor site on the host cell membrane through attachment proteins in the capsid or via glycoproteins embedded in the viral envelope. The specificity of this interaction determines the host—and the cells within the host—that can be infected by a particular virus.
Most of the animals that are adapted to the tropical rainforest are those that have developed and camouflaged into the surroundings and these animals and birds are both nocturnal and daytime predators and prey as the tropics are itself full of biodiversity reserve as these forests are considered as the hotspots on the planet.
An example of this is the spider monkey that is well-adapted to the surrounding as they are climbers and most live on trees and spends most of there time in forests the ability to walk like spiders and provides them fast movement and agility to there surroundings.
