Answer the following:
Q.1: During breathing cycle, the lungs always contain a ________________ of air.
Ans: residual volume
Q.2: The walls of alveoli contain an extensive network of _______________.
Ans: blood vessels
Q.3: Why is carbon dioxide mostly transported in dissolved form in our blood ?
Ans: Because it is more soluble in water than oxygen
Q.4: __________ transports food, carbon dioxide and nitrogenous wastes in the dissolved form.
Q.5: Oxygen from the lungs come to the thin walled upper chamber of the heart – _______________.
Ans: Left atrium
Q.6: ___________ ensure that the blood does not flow backwards when the atria or ventricles contract.
Q.7: Which animals have three-chambered hearts ?
Ans: amphibians and reptiles
Q.8: What is blood pressure ?
Ans: The force that blood exerts against the wall of a vessel is called blood pressure.
Q.9: What is systolic pressure ?
Ans: The pressure of blood inside the artery during ventricular systole (contraction) is known as systolic pressure. Normal systolic pressure is 120 mm of Hg.
Q.10: What is diastolic pressure ?
Ans: The pressure of blood inside the artery during ventricular diastole (relaxation) is diastolic pressure. Normal diastolic pressure is 80 mm of Hg.
Q.11: Blood pressure is measured with an instrument called ______________.
Q.12: What causes high blood pressure (hypertension) ?
Ans: It is caused due to the constriction of arterioles, which results in increased resistance to blood flow.
Q.13: ___________ are the vessels that carry blood from the heart to various organs of the body.
Q.14: _____________ collect blood from different organs and bring it back to the heart.
Q.15: The smallest vessels which have one-cell thick walls are known as ______________.
Q.16: ______________ carries digested and absorbed fat from intestine and drains excess fluid from extra cellular space back into the blood.
Q.17: _____________ transports the products of photosynthesis from the leaves to the other parts of the plant.
Q.18: What is transpiration ?
Ans: The loss of water in the form of vapour from the aerial parts of the plant is known as transpiration.
Q.19: The transport of soluble products of photosynthesis is known as __________________.
Q.20: Each kidney has large number of filtration units called _____________.
Q.21: Urine is stored in the _________________.
Ans: urinary bladder
Q.22: Daily, The initial filtrate in kidneys in a healthy body is _______.
Ans: 180 L