Tag: transportation in animal and plants

Questions Related to transportation in animal and plants

Choose the correct answer from the alternatives given.
In an one-circuit circulatory system, blood pressure:

biology human body and organ system blood pressure circulatory system transportation in animal and plants

  1. cannot be determined

  2. is higher at the intestinal capillaries than at the gill capillaries

  3. drops significantly after gas exchange has taken place

  4. is constant throughout the system

Show answer
Correct Option: C
Explanation:
In a single-circuit circulatory system as seen in fishes, the oxygenated blood from the gills does not enter the heart. The heart does not receive oxygenated blood, so known as venous heart. It is directly distributed in the entire body, after which it loses its pressure due to the absence of pushing force. Only the deoxygenated blood enters the auricle and then the ventricle. The deoxygenated blood enters the gills for oxygenation from the ventricle. Blood has a slow flow and low pressure.
So, the correct option is 'drops significantly after the gas exchange has taken place'.

Which of the following trigger renin-angiotens in the system?

biology human body and organ system blood pressure circulatory system transportation in animal and plants

  1. Increased blood sugar

  2. High CI concentration in the blood

  3. Lowered blood pressure

  4. Increased sodium retention

Show answer
Correct Option: C
Explanation:
When renal blood flow is reduced, the enzyme renin is secreted by the kidney cells. This promotes the conversion of angiotensinogen, produced by the liver, to angiotensin, which stimulates the production of aldosterone by the adrenal cortex. Aldosterone increases the reabsorption of sodium and water and the excretion of potassium by the kidneys. This raises the blood volume and the flow of blood through the kidneys, suppressing renin production and reducing aldosterone secretion.
So the correct answer is lowered blood pressure.