Subject :NSO Class : Class 7
Refer to the given figure of a sectional view of a blood vessel having a valve. Select the correct statement regarding it.
A Blood flows from X to Y.
B Muscles in the wall relax and close the valve, preventing backflow.
C The elastic wall causes the valve to close between heart beats.
D The valve is forced open when the blood pressure at Y is greater than at X.
Why b and c are wrong?
Ans 1:
Class : Class 3
.