STD 11 - 13. Plant growth and development — BIOLOGY STD 11 Science — Question

$I$. $ECG$ is of a great clinical significance

$II$. Electrocardiograph is the recording of electrical changes in cardiac muscles during the cardiac cycle

$III$. To obtain a standard $ECG$, a patient is connected to the machine with $3$ electrical electrodes (one to each wrist and to the left ankle)

$IV$. Normal activities of the heart are regulated intrinsically

$V$. Electrocardiogram is the electrical activity of heart

The option with correct statements is