Answer:d) contracting her pupils and increasing secretion of stress hormones.
Explanation:
Peripheral nervous system consists of 3 major neuronal levels: vegetative (reticular formation and brain stem), limbic system and neocortical level. The RAS is the link between the brain and the spinal cord.
Brain stem consists of pons, medulla oblongata and mesencephalon. Brain stem is responsible for involuntary functions such as heart beat, respiration and vasomotor activity. Limbic system represents the emotional control center. It consists of thalamus, hypothalamus and pituitary gland and maintains homeostasis. Neocortical part processes sensory information and regulates emotional responses.
Autonomic nervous system (ANS) regulates visceral activities and organs (circulation, digestion, respiration and temperature). ANS has two divisions: sympathetic and parasympathetic nervous system.Parasympathetic nervous system regulates homeostasis via the release of acetylcholine (Ach). Parasympathetic nervous system is responsible for energy conservation and relaxation.
There are three stages in the stress response: immediate effects of stress, intermediate effects of stress and prolonged effects of stress.
Option A, When cells undergo meiosis, the cells of sexual reproduction are divided into two parts, the first is the meiotic division that is reductional division, and the second is an equational division because they have the same number of chromosomes of the stem cell And in this situation, there is no duplication of DNA.
The correct answer is a nutrient runoff.
Nutrient runoff is a major reason for eutrophication of surface waters, in which extra amount of nutrients, generally phosphorus or nitrogen, instigate growth of algae. Sources of nutrient pollution involve surface runoff from pastures and farm fields, emissions from combustion, and discharges from septic tanks.
The answer is <span>insect and pest populations decreased.
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DDT (dichlorodiphenyltrichloroethane) was used as an insecticide which is a substance used to kill insects. That resulted in decrease in insect and pest populations. It is a persistent and non-degradable insecticide, but as well organic pollutant readily accumulated to soils and consequently affects organisms.
A. two identical nuclei
<span>Mitosis, simply put, is the division of the nucleus of a cell. It is the phase in the cycle of a cell in which the two chromosomes in a cell divide and separate in a nucleus of their own. These chromosomes are completely identical. As a result of mitosis, two identical cells are formed and are known as daughter cells. This process copies and transfers DNA into both the cells that are formed as a result of Mitosis.</span>