Note 3|standard 12|Sexual reproduction in flowering plants|Structure of microsporangia| notes| NCERT| Biology

Sexual reproduction in flowering plants (New syllabus chapter 1 / old syllabus Chapter 2)

Structure of microsporangia|reproduction in flowering plants|short notes| NCERT| standard 12| Biology

Note 3

Structure of microsporangia

section of anther and zoomed in view of microsporangium

→Appears circular in outline

→Function of microsporangia - gamete (microspore/pollen) production

      →→Gamete are very delicate and essential for plant - require protection 

→Surrounded by 4 layers

1. Epidermis - outermost layer 
2. Endothecium  
3. Middle layer - 2-3 lined layer  
4. Tapetum - innermost layer

→Function of first 3 layers- protection and help in dehiscence (ખરવું/झड़ना) of anther

→Tapetum - 

- pyramidal shape cells (extra information)

- function - nourishment and development of pollen grain

- possess dense cytoplasm - dense cytoplasm is present in all cells that have function of secretion (just for your understanding)

- secrets calase enzyme - to remove calose from microspore tetrad (just for your understanding)

- secrets sporopollenin - hardest plant substance which is required for pollen development

- have more than 1 nucleus - because more

 secretion required due for nourishment - hence more genetic expression needed 

→Center of microsporangia - sporogenous tissues(microsporogenous tissue)

-  seen in young anther

- a group of compactly arranged cells

- homogeneous cells - cells of same type

- these cells mature and convert into Microspore Mother cell(MMC)/pollen Mother cell(PMC)

Happy learning!

Thank you for reading

Manish Mevada

Urvi Bhanushali