The interaction between the organisms can be beneficial harmful or neutral depending on the types of organisms. Different types of interaction are mutualism, ammensalism and commensalism.
The competition occurs when the individual compete for the same resources or for the habitat. The competition results in the exclusion of one species and determines the distribution of other species.
Researchers found that chronic exposure to a stress hormone causes modifications to DNA in the brains of mice, prompting changes in gene expression. The new finding provides clues into how chronic stress might affect human behavior.
