Answer:
A decrease in biodiversity causes a decrease in ecosystem stability, because a change to one organism will have a greater impact on the entire ecosystem. With greater biodiversity, the loss of one type of organism could be moderated by the adaptation of other organisms to fill its role.
The correct answer is HPA axis.
The Hypothalamic-Pituitary-Adrenal (HPA) axis is one of the most important neuroendocrine systems, which regulates the stress response and other functions such as the digestion, mood, emotions and the immune system.
The hypothalamus, when triggered by a possible stressor, releases two hormones; the vasopressin and the corticotropin-releasing hormone (CRH). CRH, in turn, triggers the release of the adrenocorticotropin hormone (ACTH) from the pituitary gland. As a result of the secretion of ACTH, cortisol is secreted by the adrenal cortex.
Cortisol is a steroid hormone, considered to be our body's stress hormone.
The answer would be A. the arrangement of DnA
