<span>It is believed that in the evolutionary history of life on Earth, there was the RNA world before DNA and proteins.</span> <span>RNA is a self-replicating molecule that can store and replicate genetic information and catalyze (ribozymes-RNA enzymes) reactions that are important for life. Because of these characteristics, it is possible that RNA world really existed. Because of the better stability and durability than RNA DNA later it became the predominant storage molecule.</span>
Answer:
Explanation:
Electric field is a vector quantity whose direction is defined as the direction that a positive test charge would be pushed when placed in the field. Thus, the electric field direction about a positive source charge is always directed away from the positive source.
Answer:
The correct answer will be option-A
Explanation:
The sympathetic nervous system is a type of the autonomic nervous system which mediates the homeostasis and stress response.
During stress condition, it initiates the hormonal response called fight or flight response by secreting acetylcholine from the adrenal medulla which stimulates the secretion of the epinephrine and norepinephrine.
This hormone produces an observable response like increase in the heart rate, widening of the bronchial passages, constriction of the blood vessels, pupillary dilation, perspiration and <em>decreases motility of the large intestine.
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Thus, option-A is the correct answer.
<span> shifts in the Earth's crust, earthquakes</span>
