In the following diagrammatic representation of a standard $ECG$,the '$T$' wave represents:

Match List $I$ with List $II$ :

List $I$	List $II$
$A$. $P$ wave	$I$. Heart muscles are electrically silent.
$B$. $QRS$ complex	$II$. Depolarisation of ventricles.
$C$. $T$ wave	$III$. Depolarisation of atria.
$D$. $T-P$ gap	$IV$. Repolarisation of ventricles.

Choose the correct answer from the options given below:

Complete the missing words in the statements given below:
$(a)$ Plasma without clotting factors is called serum.
$(b)$ $.........$ and monocytes are phagocytic cells.
$(c)$ Eosinophils are associated with $.........$ reactions.
$(d)$ $.........$ ions play a significant role in clotting.
$(e)$ One can determine the heart beat rate by counting the number of $.........$ in an $ECG$.

Write the differences between $P$-wave and $T$-wave.

If repeated checking of blood pressure of an individual shows systolic $140$ $mm$ $Hg$ and diastolic $90$ $mm$ $Hg$ or higher,it indicates hypertension.

$QRS$ complex is related to