Ans 1: Human erythrocytes lack a nucleus, but frog erythrocytes have nuclei and are capable of dividing.
2: Haemoglobin – a specialised protein that binds to oxygen in the lungs so that the oxygen can be transported to the rest of the body. At high altitudes, oxygen molecules are further apart because there is less pressure to "push" them together. This effectively means there are fewer oxygen molecules in the same volume of air as we inhale. So because of low availability of oxygen the hemoglobin level in the blood is rises rt high altitude in order to increase the binding efficiency for oxygen molecules and vice versa.
3: An elevated blood sugar level can determine diabetes and pre-diabetes.
4: Atherosclerosis, sometimes called "hardening of the arteries," occurs when fat, cholesterol, and other substances build up in the walls of arteries. These deposits are called plaques. Over time, these plaques can narrow or completely block the arteries. This results in the decrement in the blood flow to the heart which eventually causes chest pain, shortness of breath or other signs and symptoms of coronary artery disease. Uncontrolled coronary artery disease or a complete blockage of arteries can cause a heart attack.
