Which substance is in higher concentration in blood than in glomerular filtrate?

In the process of transcription,the sigma factor is important for:

In the reaction,$C_2H_5OC_2H_5 + CO \xrightarrow[150^{\circ}C, 500 \text{ atm pressure}]{BF_3} X$. What is $X$?

$A$ vertical bar magnet is dropped from a position on the axis of a fixed metallic coil as shown in fig-$I$. In fig-$II$,the magnet is fixed and a horizontal coil is dropped. If the acceleration of the magnet and the coil are $a_1$ and $a_2$ respectively,then:

If $A(2,-1)$ and $B(6,5)$ are two points,the ratio in which the foot of the perpendicular from $P(4,1)$ to $AB$ divides $AB$ is:

When $FeCl_3$ reacts with $K_4[Fe(CN)_6]$,which of the following compounds is formed?