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Thursday, March 26, 2015

Anthers and Stigmas and Styles, Oh My!


Flowers are have both male and female reproductive organs, so any two flowers of the same species have the ability to breed.  The male reproductive organs, or the stamens, are made of a gametophyte-containing anther and a filament that supports it.  The female organs are in the middle of the flower, a part called the carpel, and contain female gametophytes in the ovary.  The male gametophytes are in the form of pollen, which (if due to wind or possibly a bee) land on the stigma, at the top of the carpel.  The gametophytes in the pollen are transferred to the ovary, at the bottom of the carpel, where they fertilize the ovules.
anthers in the middle of the petal
a more focused view of the anthers, with stigmas to the side
the ovary, with ovules seen at the top left

Blog Post 10: Anthers and Stigmas and Styles, Oh My!

In class, we dissected the Brassica oleracea with a dissecting microscope at 40x magnification to see the different parts of a flower. Below are all of the parts that we found.
 
This picture is of the male reproductive anatomy in a flower, consisting of the anthers and the filament, which together is called the stamen. The filament a green stalk at the bottom of the anthers, but isn't shown in this picture. The anther is where meiosis occurs and the sperm cells are produced, and then are shot through the filament and into the female's ovaries. 
 
This is a picture of the female reproductive system, the carpel, which is consisted of the stigma, the style, and the ovaries. The eggs are created in the stigma, the little nub at the top. Then the eggs are sent though the style, the long green stalk, and then into the ovaries, where the sperm and eggs meet. 

 
 This image is of the female ovaries. On the inside, there are little round balls, called the ovules, that contain female gametophytes. 

Plants go through a very specific reproduction process. Pollen cones, or male cones, produce pollen grains which divide to produce two sperm nuclei. Seed cones however, are the female part of the plant. They have ovules which produce haploid cells that grow and mature into large egg cells. The sperm nuclei are spread in the spring, and are caught by the pollination drops on seed cones. The sperm grows a structure called a pollen tube that reaches and fertilizes the eggs of a plant. A new embryo is formed, and it becomes a germinated seed, then a seedling, and it then eventually grows into another plant.