1. In an experiment, a man drank a litre of water, his urine output increases so that after hours he had eliminated the extra water. When he drank a litre of 0.9% of sodium chloride (common salt), there was little or no increase in his urine production. Explain the difference in this result.
2. when a dog is hurt. It hangs out it tongue and pants. why should this have a cooling effect
3. In the artificial kidney, a patient's blood is circulated through dialyses tubling immersed in a warm solution of sugar and salt. Explain how this result in the elimination from his blood of Nitrogenous waste without loss of essential glucose and salt.
4. Why is a person whose heart valves is damaged by disease unable to participate in active sport?
5. In an actively photosynthesing cell, the sugars being formed are quickly converted to starch. What is the Biological advantage of this in term of osmosis.
http://en.wikipedia.org/wiki/Osmosis
http://en.wikipedia.org/wiki/Panting
http://en.wikipedia.org/wiki/Dialysis
http://en.wikipedia.org/wiki/Aortic_insufficiency
http://en.wikipedia.org/wiki/Heart_valves#See_also
1. The difference in urine production between drinking water and drinking saltwater can be explained by the process of osmosis. Osmosis is the movement of water molecules across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration. In the case of the man drinking water, the water is absorbed into the bloodstream, increasing the solute concentration in the blood. This higher solute concentration triggers the kidneys to produce more urine in order to eliminate the excess water and maintain balance.
On the other hand, when the man drinks saltwater, which contains sodium chloride, the presence of solutes (sodium and chloride ions) in the saltwater increases the solute concentration of the liquid. This higher solute concentration in the saltwater makes it more similar to the solute concentration in the blood. As a result, osmosis does not drive the movement of water from the saltwater into the bloodstream, and therefore there is little or no increase in urine production.
2. When a dog is hurt, it hangs out its tongue and pants in order to cool down its body. Dogs do not sweat like humans do, so panting is an important way for them to regulate their body temperature. As the dog pants, it breathes heavily, which helps to increase airflow over the moist surface of the tongue. This increased airflow causes evaporation, which leads to cooling of the tongue and blood vessels in the tongue.
The evaporation of moisture from the tongue helps to dissipate heat from the dog's body. When the dog is panting, the moist surfaces of the mouth, tongue, and airways are exposed to the air, and as the saliva and moisture on these surfaces evaporate, they carry away heat from the body. This cooling effect helps to prevent overheating and helps the dog to maintain a more stable body temperature.
3. In artificial kidney treatment, the patient's blood is circulated through dialysis tubing immersed in a warm solution of sugar and salt. This technique is called hemodialysis. The warm solution of sugar and salt is known as the dialysate.
During hemodialysis, the dialysis tubing acts as a semi-permeable membrane. It allows small waste molecules (such as nitrogenous waste, urea, and creatinine) and excess ions to pass out of the patient's blood through the tubing and into the dialysate. At the same time, it prevents larger molecules like glucose and essential electrolytes (salts) from crossing the membrane.
The dialysate is carefully formulated to provide an environment with the same concentration of essential electrolytes as the patient's blood. This is important because it ensures that important ions like sodium, potassium, and calcium are not lost during dialysis. However, the dialysate has a lower concentration of waste products compared to the patient's blood. This concentration gradient allows for the movement of waste from the blood to the dialysate.
Overall, the warm dialysate, along with the semi-permeable membrane, helps in the removal of nitrogenous waste from the patient's blood without significant loss of essential glucose and salts.
4. When a person's heart valves are damaged by disease, such as aortic insufficiency, they may be unable to participate in active sports due to several reasons. Aortic insufficiency is a condition where the aortic valve fails to close properly, leading to the backflow of blood from the aorta back into the left ventricle of the heart.
Damaged heart valves can result in reduced cardiac output, which means that the heart is unable to pump blood efficiently. During physical activity, the body's demand for oxygen and nutrients increases, requiring the heart to pump more blood. However, with damaged heart valves, the heart may not be able to supply sufficient blood to meet the increased demand, leading to fatigue and decreased exercise tolerance.
In addition, the backflow of blood caused by aortic insufficiency can disrupt the normal circulation of blood and oxygen to the body's tissues. This can result in reduced exercise capacity as the body receives an inadequate oxygen supply. It may also lead to symptoms such as shortness of breath and chest pain during physical exertion.
Therefore, individuals with damaged heart valves may be advised to avoid participating in active sports or strenuous physical activities to prevent complications and ensure their safety.
5. In an actively photosynthesizing cell, the sugars produced through photosynthesis are quickly converted into starch. This conversion of sugars to starch serves as a biological advantage in terms of osmosis.
Osmosis is the movement of water molecules across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration. In plant cells, sugars and other solutes contribute to the solute concentration inside the cell. When a cell actively produces sugars through photosynthesis, the high concentration of sugars inside the cell can create a hypertonic environment, meaning the solute concentration inside the cell is higher than the solute concentration outside the cell.
The conversion of sugars to starch helps to maintain a lower solute concentration inside the cell. Starch is a larger, more complex molecule than sugars, and its presence reduces the solute concentration inside the cell. This decrease in solute concentration helps to prevent excessive water loss from the cell through osmosis.
By converting sugars to starch, the plant cell can regulate osmosis and maintain a more balanced water balance. This is important for preventing the cell from losing too much water, which could lead to dehydration, shrinkage of the cell, and ultimately, damage to the cell's structure and function.