List of top Science Questions on Circulatory System asked in CBSE Class X

Name the blood vessel that brings (i) oxygenated blood (ii) deoxygenated blood, to the human heart. Also name that chamber of the heart which receives deoxygenated blood and state how deoxygenated blood from this chamber is sent to the lungs for oxygenation. 

Select TRUE statements about lymph from the following: 
A. Lymph vessels carry lymph through the body and finally open into larger arteries. 
B. Lymph contains some amount of plasma, proteins and blood cells. 
C. Lymph contains some amount of plasma, proteins and red blood cells. 
D. Lymph vessels carry lymph through the body and finally open into larger veins. 
The true statements are:

Which of the following statement(s) is (are) true about human heart?
(a) Right atrium receives oxygenated blood from lungs through pulmonary artery.
(b) Left atrium transfers oxygenated blood to left ventricle which sends it to various parts of the body.
(c) Right atrium receives deoxygenated blood through vena cava from upper and lower body.
(d) Left atrium transfers oxygenated blood to aorta which sends it to different parts of the body.