Given below the example of few chemicals like:-

Sodium oxalate, sodium chloride, sodium citrate, EDTA, sodium hydroxide etc.

Out of these how many chemicals having capability to prevent the blood clotting?

The haemocytometer is a thickened glass slide with small chamber of grids cut into the glass and is used to count cells. Each chamber has a fixed volume and is etched into nine large squares (see figure, $P$ to $X$ ), each measuring $1\mathrm{mm}\times 1\mathrm{mm}$ and $0.1\mathrm{mm}$ deep. Each large corner squares $(P,R,V$ and $X)$ contain $16$ small squares. With a coverslip in place, each of these small squares represents a volume of $0.1{\mathrm{mm}}^3$ $\left(1.0{\mathrm{mm}}^2\right.$ area $\times 0.1\mathrm{mm}$ depth ) or ${10}^{-4}{\mathrm{cm}}^3$. The number of cells counted in $4$ large corner squares was $400$, with the conversion factor as $1000.$

$\mathrm{Number} \mathrm{of} \mathrm{cells}per\mathrm{ml}=\frac{ \mathrm{Number} \mathrm{of} \mathrm{cells} \mathrm{counted} }{ \mathrm{Large} \mathrm{squares} \mathrm{counted} }\times \mathrm{Dilution} \mathrm{factor}$

Given this information, calculate the total number of cells suspended in a volume of $5\mathrm{ml}$, considering that the cells were diluted $1: 2$ before counting.

Given below are two statements:

Statement I: The coagulam is formed of network of threads called thrombins.

Statement II: Spleen is the graveyard of erythrocytes.

In the light of the above statements, choose the most appropriate answer from the options given below:

Study the following.
A) Blood coagulation is also called haemolysis.
B) Blood clotting is a change in plasma.
C) Serum does not contain clotting factors like prothrombin and fibrinogen.
D) Proconvertin is involved in extrinsic pathway.

Select the incorrect statement.

What does "X" and "Y" indicate in the given chart?

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$