Ethylene
Explanation:
Introduction
The growth and development of plants under varied environmental conditions determine agricultural production. The growth, development, and senescence of plant’s organs can influence crop production by modulating photosynthesis, nutrient remobilization efficiency, and harvest index (Paltridge et al., 1984; Jing et al., 2005; Iqbal et al., 2012). Phytohormones have been shown to increase growth and yield of plants. The phytohormone ethylene controls growth and senescence of plants (Reid, 1995; Lutts et al., 1996; Thompson et al., 1998; Pierik et al., 2006; Masood et al., 2012; Nazar et al., 2014). Ethylene is regarded as a multifunctional phytohormone that regulates both growth, and senescence. It promotes or inhibits growth and senescence processes depending on its concentration, timing of application, and the plant cell
Answer:
Sympathetic nervous system
Explanation:
Under stress conditions, the sympathetic division of the autonomic nervous system prepares the body by exhibiting flight or fight response. It includes some physiological changes in the body during stress conditions such as before and during exams.
Some of the physiological responses of the sympathetic nervous system are rapidly pounding, dilated pupils of eyes, deep breathing, dry mouth, and sweaty skin. It also shunts the blood circulation towards active skeletal and cardiac muscles. Dilation of bronchioles to increase ventilation to facilitate the delivery of more oxygen to the body cell is another change stimulated by the sympathetic nervous system. Therefore, the mentioned responses are due to the activation of the sympathetic nervous system of the student since he is in the stress of the exam.
Answer:
0.062 moles of hydrogen gas
Explanation:
We must first out down the reaction equation before we can attempt to solve the problem.
Mg(s) + 2HCl(aq) ----> MgCl2(aq) + H2(g)
Next we obtain the number of moles in 1.5 g of magnesium metal from;
Molar mass of magnesium = 24.3 gmol-1
Number of moles of magnesium= mass/molar mass = 1.5g/24.3gmol-1 = 0.062 moles
From the reaction equation;
1 mole of magnesium metal yields 1 mole of hydrogen gas
0.062 moles of magnesium metal will yield 0.062 moles of hydrogen gas
Therefore, reaction of 1.5g of magnesium metal with excess hydrochloric acid will yield 0.062 moles of hydrogen gas.
