Question

MULTIPLE CHOICE

1.After reading the paragraph, answer the question that follows

Two hormones are involved in maintaining blood sugar levels at the set point (about 90 mg of glucose/100 ml of blood). When blood sugar levels rise above the set point, the hormone insulin signals the liver to absorb the excess sugar. When blood sugar levels drop below the set point, the hormone glucagon signals the liver to release its stored glucose to the bloodstream. In juvenile onset diabetes, the body doesn't produce enough insulin and insulin supplements are required.

Based on your understanding of homeostasis, for negative feedback control of blood glucose levels to function properly:

A.the control center for glucose must be somewhere in the digestive system.

B.the absorption of sugars by the liver must ultimately reduce levels of circulating insulin.

C.there must be several other hormones involved (in addition to insulin and glucagon).

D.the body must prevent glucose levels from changing even slightly.

.

2.After reading the paragraph, answer the question that follows

Two hormones are involved in maintaining blood sugar levels at the set point (about 90 mg of glucose/100 ml of blood). When blood sugar levels rise above the set point, the hormone insulin signals the liver to absorb the excess sugar. When blood sugar levels drop below the set point, the hormone glucagon signals the liver to release its stored glucose to the bloodstream. In juvenile onset diabetes, the body doesn't produce enough insulin and insulin supplements are required.

If you had just eaten a meal high in carbohydrates which hormone would be responsible for returning your sugar levels to the set point?

A.insulin

B. glucose

C. pancreas

D. glucagon

E .liver

3.Which of the following is NOT true about counter-current gas exchange in the bird lung?

A. Air flow through the lung is in the opposite direction as blood flow.

B. The air has a higher oxygen concentration than the blood passing nearby.

C. The blood has a higher carbon dioxide content that the air passing nearby.

D. A higher percentage of oxygen is able to be extracted in bird lungs than in human lungs.

E. The blood has a higher oxygen content than the air passing nearby.

Answer 1

1.The tendency to maintain a stable, constant internal environment is termed as homeostasis.It depends on the ability of our body to oppose negative changes.

In case of diabetes : Insulin decreases the concentration of glucose in blood.Insulin gives a signal to the cells of the body to tuse the glucose as fuel.It helps to convert glucose to glycogen (storage in liver ).Glucagon increases the concentration of glucose.if there no enough glucose in blood glucogon is released and it convert glycogen in liver to glucose.Diabetes happen when one's pancreas cannot make enough insulin.In this condition the body cant utilize the glucose roduced in the blood.this causes symptoms like inceased urination, thirst and dehydration ,the person feels tired.The control centre is the pancreas.

2.After you take a meal your glucose level in the blood increase and insulin is secreated by beta cells of pancreas.

It triggers body cells to take up glucose and used for cellular respiration .glucose is removed from blood and stored in liver as glycogen.

3.E

Birds have lungs and 9 air sacs .The air sacs helps oxygen rich air moving in one direction through their respiratory system .In bird lungs more oxygen is available to diffuse into the blood.With the help of air sacs, the unidirectional air flow ,helps birds to take more oxygen even during exhalation.They can even breath at higher elevations because of their lung structure.The avian respiratory system delivers oxygen from air and removes carbondioxide.This system keep the volume of air in lungs nearly constant.