Cellular respiration is carried out by

Heartwood differs from sapwood in

In a longitudinal section of a root,starting from the tip upward,the four zones occur in the following order:

Which of the following pairs is incorrectly matched?

If $D, E$ and $F$ are respectively the mid-points of $AB, AC$ and $BC$ in $\triangle ABC$,then $\overrightarrow{BE} + \overrightarrow{AF}$ is equal to :

The excess pressure inside a spherical soap bubble of radius $1 ~cm$ is balanced by a column of oil (specific gravity $= 0.8$),$2 ~mm$ high. The surface tension of the bubble is: (in $~N/m$)