Tuesday, May 18, 2010

What happens when the pollen reaches the egg?

It's either pollination occurs or fertilization occurs. I've read this material I'll quote for you and still trying to figure that out myself.





From the encyclopedia under the heading fertilization:





"After the pistil is pollinated, the pollen grain germinates in a response to a sugary fluid secreted by the mature stigma. From each pollen grain, a pollen tube grows out attempting to travel into the ovary by creating a path through the female tissue. The vegetative (or tube) and generative nuclei of the pollen grain pass into its respective pollen tube. The growth of the pollen tube is controlled by the vegetative (or tube) nucleus. Hydrolytic enzymes are secreted by the pollen tube to digest the female tissue (stigma and style) as the pollen tube grows. During pollen tube growth toward the ovary, the generative nucleus divides to produce two separate sperm nuclei - a growing pollen tube therefore contains 3 separate nuclei. The pollen tube does not directly reach the ovary in a straight line. It travels near the skin of the style and curls to the bottom of the ovary, then near the receptacle, it breaks through the ovule through the micropyle (an opening in the ovule wall) and reaches the ovum (or egg cell) to fertilise it. This is the point when fertilisation actually occurs. Note the pollination and fertilisation are two separate processes. After being fertilised, the ovary starts to swell and will become a fruit. With multi-seeded fruits, multiple grains of pollen are necessary for syngamy with each ovule."





Okay, I read all that and it seems to make a distinction between the two. This second link has a lot of stuff on pollination too:





"Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the structure that contains the ovule (female gamete). The receptive part of the carpel is called a stigma in the flowers of angiosperms and a micropyle in gymnosperms."





Basically do this, don't use either word. Just say that the plant is now able to reproduce itself. It should at that point just release the seeds which are now viable and they will land a ways away in the dirt and some will take root and survive but most won't.

What happens when the pollen reaches the egg?
mg really had the best answer. Thank you for selecting mine. In retrospect, you need to use the word fertilization to get the points I believe. It's not the points that are important but the knowledge you gain whether it is right or wrong that will get you through college. Report It

Reply:Basically fertilization occurs, but the following should be noted. Pollen is actually a plant itself, it is called the male gametophyte of the plant. Pollen contains generally one sperm, but in flowering plant it contains two sperm. One sperm is always used to fertilize the egg. In flowering plants the second sperm goes and fuses with the polar body of the female gametophyte, which contains the egg, and causes the formation of the endosperm which is used as nutritive tissue for the newly fertilized zygote.
Reply:Here's a very nice site to click on below that should be helpful:


http://plantphys.info/Plants_Human/polle...

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