Angiosperm Life Cycle

Angiosperm Life Cycle

By: Ankit Datta

Summary of video:
This video summarizes the reproductive cycle of angiosperms. Angiosperms are flowering plants that have a specialized organ called an ovary to produce seeds and protect it while it is still forming. This video discusses: the parts of the flower, pollen development, egg development, pollination, double fertilization, seed development and fruit development. First, the parts of the flower. A flower has sepals which cover growing buds, petals, filaments ( the long and skinny, tube-looking things) and anthers (yellow buds on the filament) which together, combine to make the male part of the flower. This is also the structure in which pollen is produced. The female part of the flower is made up of: the stigma (the opening of the vase-looking structure), the style (the long neck), and the ovary (the bottom swollen part). These three together form the carpel which is the female part. Next, the video addresses pollen development. Pollen develops inside the stamen where a diploid microspore mother cell undergoes meiosis and then mitosis to become pollen grains which are male gametophytes. Next comes egg development. Ovules inside the ovary produce eggs. Inside, a diploid megaspore mother cell undergoes meiosis to form megaspores. Only 1 out of 4 survives and then goes on through 3 rounds of mitosis to make an egg and an endosperm. Next is pollination. Wind and pollinators help plants pollinate where a pollen grains lands on the stigma. Next is double fertilization where the pollen grain has two parts: tube and generative. The tube cell attaches onto the egg cell and the generative cell makes two sperm, one for the egg to produce a zygote and one for the endosperm to make a triploid endosperm. Next is seed development. The ovule slowly over time becomes the seed and everything inside becomes the seed. Finally, there is fruit development. The ovaries swell and the petals fall off and the ovary grows completely to become a fruit.

Relevance to class:

This video discusses angiosperms and its life cycle. In this unit, we discussed plant evolution and how angiosperms were the last to evolve and are the only type of plant that have ovaries and flower in order to attract pollinators. We are also discussing the different parts of a flower and this video adequetly describes each part and its functions.

Video URL: http://www.youtube.com/watch?v=AykzPemLs7Q
Creator: Craig Savage
Date published: April 9, 2012