Answer: The drug abuse is influenced by the environment and exerts influence on the gene expressions.
Explanation:
The genetic make up of the person is decides, which genes will be expressed and develop a trait in an individual. But this genetic expression can be influenced by the environmental factors like food, exposure to sunlight, and others. This study which relate environment with the genetic make up is called epigenetics. No person is drug addict by birth but the consumption of drug can influence the genetic make up and traits in a abuser. So here, the environment is influencing the genetic basis of a abuser.
1. The group nearest the end or with the shortest stem of a phylogenetic tree has evolved most recently. In this case it is eutherians.
2. The group with the longest stem has been around the longest: fish
3. A direct common ancestor will share the same immediate line, like marsupials and eutherians. Fish and marsupials do not have a common direct ancestor.
The cell cycle is the replication and reproduction of cells, whether in eukaryotes or prokaryotes. It is important to organisms in alot of ways, but overall it allows them to survive.