Answer:
The correct answer is the endocrine system.
Explanation:
The sympathetic division of the autonomic nervous system and the endocrine system are the two prime systems that take part in the stress response.
At the time of acute or chronic stress, the endocrine system first makes the hypothalamus to discharge CRH or corticotropin-releasing hormone into the bloodstream. The release of CRH further makes the anterior pituitary to discharge ACTH or adrenocorticotropic hormone into the blood. This further stimulates the adrenal cortex to discharge cortisol, that is, one of the glucocorticoid hormone into the bloodstream.
The cortisol finally makes the organs and tissues present within the body to effectively cope up with the initial stress stimulus.
Answer:
The biologist is studying about the ecological community.
Explanation:
The ecological community refers to the community in which population of different types of species survives together. As the biologist is observing about the interaction of different populations of Pennsylvania region, it can be inferred that the he is studying about the ecological community of Pennsylvania region.
The population surving in the community interact with each other through different modes of interaction. It may either parasitic, or mutual, or competitive or predication or commercialism.
Answer:
Cells divide twice
Explanation:
Meiosis may be defined as the process of cell division in which a single cell divides to give four daughter cells and each daughter cells have half number of chromosomes.
Meiosis is also known as reduction division as the chromosome number reduces upto half in the progeny cells as compared with the parent cell. The cells divide twice in meiosis and give rise to four daughter cells.
Thus, the correct answer is option (4).