The anther is the pollen-producing part of the stamen (male reproductive organ of a flower). A typical anther is dithecous, meaning it has two distinct thecae (groups of sporangia), each containing two microsporangia (pollen sacs). In cross-section, a mature anther shows: two lateral lobes connected by a sterile connective tissue region that may bear a small protrusion. Each lobe contains two microsporangia (pollen sacs) — giving a total of four microsporangia per anther. The microsporangia of each lobe may fuse during development to form a single cavity, but originate as two distinct structures. The entire lobe (including its two microsporangia) is sometimes called a theca, making it accurate to say each anther lobe contains two microsporangia or one theca — NCERT specifically states "each lobe contains two theca."

Each microsporangium is surrounded by four distinct wall layers (from outside to inside): Epidermis: the outermost protective layer of the microsporangium, continuous with the epidermal layer of the anther as a whole; provides mechanical protection during pollen development. Endothecium: the layer immediately below the epidermis; in mature anthers, the endothecium develops characteristic fibrous thickenings on its cell walls that help in anther dehiscence (splitting open to release pollen) by creating differential tensile forces as the anther dries out. Middle layers: one to three transient cell layers between the endothecium and tapetum that are involved in transfer of nutrients from the tapetum to the developing pollen; these layers are gradually crushed and absorbed as pollen develops, typically absent in the mature anther. Tapetum: the innermost layer directly surrounding the developing microspores and pollen grains; the most metabolically active wall layer; secretes enzymes, nutrients, sporopollenin precursors, and various proteins needed for pollen development; the tapetum typically degenerates by programmed cell death (PCD) as pollen matures, and aberrant tapetum function causes male sterility.

Microsporogenesis refers to the process by which pollen grains (microspores) are formed within the microsporangia of the anther. The process involves: Initiation: sporogenous cells in the centre of each microsporangium (surrounded by the tapetum) differentiate into microspore mother cells (MMCs, also called microsporocytes). MMCs are diploid (2n) and large cells with prominent nuclei. Meiosis: each MMC undergoes meiotic division, producing a tetrad of four haploid (n) microspores arranged in a characteristic pattern (tetrahedral, isobilateral, or linear arrangement depending on species and the sequence of division). Callose dissolution: the tetrad is initially held together by a callose (beta-1,3-glucan) wall; when the tapetum secretes callase enzyme, the callose dissolves, releasing the individual microspores into the locule (central cavity of the microsporangium). Pollen development: each released microspore undergoes a highly asymmetric mitotic division (pollen mitosis I) producing a large vegetative/tube cell and a small generative cell, forming the two-celled pollen grain. In some species, the generative cell undergoes a second mitotic division (pollen mitosis II) either before pollen shed or within the growing pollen tube, producing two sperm cells — giving three-celled pollen.

The mature pollen grain is a highly complex, specialised structure with a characteristic wall composed of two main layers: Exine (outer wall): the tough, sculpted outer layer composed primarily of sporopollenin — one of the most chemically resistant biological polymers known, capable of surviving millions of years of fossilisation and resistant to most common acids and alkalis. The sculpted patterns on the exine surface (pollen morphology — the study of which is called palynology) are species-specific and extraordinarily diverse, including smooth, spiny, ridged, pored, and many other patterns, providing one of the most reliable tools for fossil plant identification and environmental reconstruction (fossil pollen analysis). The exine also contains the apertures (pores and/or colpi) through which the pollen tube will eventually emerge. Intine (inner wall): a thinner, cellulosic inner wall beneath the exine, similar in composition to the primary cell wall of most plant cells. Germination: when a pollen grain lands on a compatible stigma, it absorbs water, undergoes metabolic activation, and the pollen tube grows out through an aperture, carrying the two sperm cells (or generative cell that will divide en route) down the style toward the ovary for fertilisation.