explain the development of pollen grains
Answers
During its development from an undifferentiated mound of cells (anther primordium)
The anther forms two general groups of cells. The reproductive or sporogenous cells give rise to the microspores and are formed from cells located centrally within the developing anther.
Explanation:
An essay is, generally, a piece of writing that gives the author's own argument — but the definition is vague, overlapping with those of a letter, a paper, an article, a pamphlet, and a short story. Essays have traditionally been sub-classified as formal and informal. Formal essays are characterized by "serious purpose, dignity, logical organization, length," whereas the informal essay is characterized by "the personal element (self-revelation, individual tastes and experiences, confidential manner), humor, graceful style, rambling structure, unconventionality or novelty of theme," etc.[1]

Essays of Michel de Montaigne
Essays are commonly used as literary criticism, political manifestos, learned arguments, observations of daily life, recollections, and reflections of the author. Almost all modern essays are written in prose, but works in verse have been dubbed essays (e.g., Alexander Pope's An Essay on Criticism and An Essay on Man). While brevity usually defines an essay, voluminous works like John Locke's An Essay Concerning Human Understanding and Thomas Malthus's An Essay on the Principle of Population are counterexamples.
In some countries (e.g., the United States and Canada), essays have become a major part of formal education. Secondary students are taught structured essay formats to improve their writing skills; admission essays are often used by universities in selecting applicants, and in the humanities and social sciences essays are often used as a way of assessing the performance of students during final exams.
The concept of an "essay" has been extended to other media beyond writing. A film essay is a movie that often incorporates documentary filmmaking styles and focuses more on the evolution of a theme or idea. A photographic essay covers a topic with a linked series of photographs that may have accompanying text or captions.
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Definitions

John Locke's 1690 An Essay Concerning Human Understanding.
The word essay derives from the French infinitive essayer, "to try" or "to attempt". In English essay first meant "a trial" or "an attempt", and this is still an alternative meaning. The Frenchman Michel de Montaigne (1533–1592) was the first author to describe his work as essays; he used the term to characterize these as "attempts" to put his thoughts into writing.
Subsequently, essay has been defined in a variety of ways. One definition is a "prose composition with a focused subject of discussion" or a "long, systematic discourse".[2] It is difficult to define the genre into which essays fall. Aldous Huxley, a leading essayist, gives guidance on the subject.[3] He notes that "the essay is a literary device for saying almost evRicha