The major product of the following reaction is

Match the following columns correctly:

Column-$I$	Column-$II$
$A$. Tapetum	$i$. Degenerates during development
$B$. Intine	$ii$. Resistant organic material
$C$. Vegetative cell	$iii$. Pollen tube
$D$. Sporopollenin	$iv$. Provides nourishment to pollen grains

Two equal resistances when connected in series to a battery,consume electric power of $60 \ W$. If these resistances are now connected in parallel combination to the same battery,the electric power consumed will be............. $W$

In the given columns, column $I$ contains the terms and column $II$ contains their descriptions. Select the correct match from the options given below.

Column $I$	Column $II$
$A$. Growth	$I$. Production of offspring.
$B$. Reproduction	$II$. Composed of one or more cells.
$C$. Metabolism	$III$. Increase in mass and increase in number of individuals.
$D$. Cellular organization	$IV$. Sum total of all chemical reactions occurring in the body.

If the chord $y=mx+1$ of the circle $x^2+y^2=1$ subtends an angle of $45^{\circ}$ at the major segment of the circle,then the value of $m$ is:

The most important ore of tin is: