They close their stomata during the day and open at night
the relationship between abotic and biotic environment is called ecosystem.
There are 4 valence electrons in an atom of carbon. Carbon is in group 4A of the periodic table. There are 6 electrons in a carbon atom but only 4 of them are valence. carbon can never form more than 4 bonds and is unhappy with less than 4.
Answer:
Physiological reactions to stress in the alarm stage include: <em>increased heart rate and blood pressure, dilated pupils, rapid and shallow breath, and increased cortisol levels.</em>
Explanation:
Hans Seyle, a medical doctor proposed a model called the General Adaptation Syndrome (GAS) to explain the effects and stages of coping with the stress. The GAS model has three stages, known as:
1. Alarm stage
2. Resistance stage
3. Exhaustion stage
The <em>alarm</em> stage is the first stage of responding to stress. During this stage, the fight-or-flight response is activated when an individual is experiencing stress. This stage involves the following physiological reactions:
1. Increased heart rate
2. Increased blood pressure
3. Dilated pupils
4. Rapid and shallow breath
5. Increased cortisol levels