Messenger and transfer RNA
Heart rate is controlled by the two branches of the autonomic (involuntary) nervous system. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). The sympathetic nervous system (SNS) releases the hormones (catecholamines - epinephrine and norepinephrine) to accelerate the heart rate. The parasympathetic nervous system (PNS) releases the hormone acetylcholine to slow the heart rate. Such factors as stress, caffeine, and excitement may temporarily accelerate your heart rate, while meditating or taking slow, deep breaths may help to slow your heart rate.
Rainwater can replace or replenish freshwater sources.
Precipitation, such as rainwater, is the source of freshwater on Earth.
When the amount of surface freshwater increases, so does the amount of groundwater.
Human activity, such as taking a bath, may change the quality of a freshwater resource. :)
<u>Answer:</u>
<em>Enzyme activity decrease at these temperatures.
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<u>Explanation:</u>
Photosynthesis is facilitated by the action of various enzymes and involves light and dark reactions. In <em>light reactions chlorophyll absorbs sunlight and creates ATP AND NADPH</em>. In dark reactions carbon is fixed using the <em>ATP and NADPH.
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The efficiency of all these activities depends on the activity of enzymes which depends on the temperature. The optimum temperature range where the enzyme activity is optimal is about <em>10°c - 20°c</em>. At low temperatures and high temperatures enzyme activity is less efficient.
<em>At a temperature above 38°c and below 0°c enzyme activity decreases.
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Answer:
The independent variable is "controlled" or held constant in the control group.
Explanation: