Question

Draw a labelled diagram of a transverse section of a mature anther.

Hint:

Anther is tetrasporangiate: 2 lobes × 2 microsporangia each = 4 pollen sacs.

Answer 1

A mature anther is bilobed and each lobe has two microsporangia, making it tetrasporangiate. \begin{center} \begin{tikzpicture}[scale=1.2] % Outline of anther \draw[thick] (0,0) ellipse (2 and 1.3); % Compartments \draw[thick] (0,-1.3) -- (0,1.3); \draw[thick] (-2,0) -- (2,0); % Microsporangia \foreach \x/\y in {-1/0.6, 1/0.6, -1/-0.6, 1/-0.6}{ \draw[thick] (\x,\y) circle (0.4); \node at (\x,\y) {Microspores}; } % Labels \node at (-2.4,0.9) {Microsporangium}; \node at (2.6,1.0) {Epidermis}; \node at (2.6,0.5) {Endothecium}; \node at (2.6,0.0) {Middle layers}; \node at (2.6,-0.5) {Tapetum}; \end{tikzpicture} \end{center} Explanation: Layers of anther wall (from outside to inside): \begin{enumerate} \item Epidermis: Protective outer layer. \item Endothecium: Provides mechanical support. \item Middle layers: 2–4 layers that degenerate at maturity. \item Tapetum: Innermost nutritive layer providing food and enzymes to developing pollen grains. \end{enumerate} Each microsporangium produces pollen grains after meiosis of microspore mother cells.