Describe the structure of anther with the help of a neat diagram

Describe the structure of anther with the help of a neat diagram 
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Ans: Structure of anther is clearly understood in the transverse section of anther. In the T.S. of a dithecous anther the two thecae are joined by connective consisting of sterile tissue. Each theca has two locules representing the microsporangia which are separated by a strip of sterile tissue known as partition wall. The two main parts of anther are anther wall and sporogenous tissue.

Anther wall: It consists of Epidermis, Endothecium, Middle layers and Tapetum.

Epidermis: It is single layered and protective in function. It has relatively thin walled smaller cells between microsporangia of same theca forming stomium. Stomium shows the signs of degenearation by the time meiosis takes place in microspore mother cells.

Endothecium: It is hypodermal in position. It is hygroscopic and consists of fibrous thickenings made of cellulose and helps in dehiscence of anther.

Middle layers: These are 1-5 layered, thin walled and ephemeral structure.

Tapetum: It completely surrounds the sporogenous tissue. Its cells have prominent nuclei and dense cytoplasm. It nourishes the sporogenous tissue. It is completely used by the time the anther shows dehiscence.

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Sporogenous tissue: It is fertile tissue. Its cells divide and redivide to form microspore mother cells which undergo meiosis to form haploid microspores in tetrads which later separate from each other and liberated individually. Individual microspores are called as pollen grains. 

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