Biologically,the most resistant plant material is:

Which one of the following statements is correct?

$A$: Each cell of the sporogenous tissue is capable of giving rise to a microspore tetrad.
$R$: The most abundant type of microspore tetrad is the product of simultaneous cytokinesis.

What are the characteristic features of the endothecium layer in the anther of $Capsella$?

If the cells of the root in a wheat plant have $42$ chromosomes,then the number of chromosomes in the cell of a pollen grain is:

Choose the correct sequence of wall layers in a microsporangium of an angiosperm, starting from the outermost to the innermost layer.