Circulatory system related to respiratory system<span> in </span>crayfish<span>. both uses gills. in respiration walking legs and maxilla move water across gills. in circulation blood</span>
<span>Both simple and complex transposons.</span>
Circumstance <span>that cause an increase in Blood Pressure:
</span>
- increasing levels of aldosterone ((influences the reabsorption of sodium and excretion of potassium in the
kidneys. This will indirectly influence the blood pressure since the
volume of blood will change)
<span>- vasoconstriction ( blood vessels increase their contraction, which equals to more pressure)
</span>
-increased release of renin (Converts angiotensinogen, secreted in the liver, into angiotensin I).
- increased activity of Angiotensin-converting enzyme ( this enzyme converts angiotensin I into angiotensin II increasing vasoconstriction).
Circumstances that cause<span> a Decrease in Blood Pressure:
</span>
<span>- decreased sodium reabsorption ( by decreasing sodium, the amount of water will also decrease or , in other words,will be excreted. Less water, will decrease volume of blood and that means less blood pressure)
</span>
- vasodilation (The smooth muscle in the <span>blood vessels decrease their contraction, which equals to less pressure)
</span>
- declining levels of ADH(ADH <span>is produced in the hypothalamus and stimulates
vasoconstriction plus it promotes water reabsorption in the kidneys. To reduce blood pressure, is important to have ADH levels reduced)</span>
Answer Choice: D
In absence of nitrogen fixation process, these substances, which are necessary for structural and functional growth of organisms, will not be formed.