The Honors student will:
Ready for a little more research on plant reproduction? There are a few more things we need to know before we make our decision on which plants will be BioDome plants. Alternation of GenerationsYou should recall that plants are classified in a variety of ways. One of the ways they are grouped is according to their methods of reproduction. Regardless of their reproductive style, one thing that all plants have in common is that they go through alternating life stages. We call this alternation of generations. There are some terms that will help you understand this material:
Non-seed plants, like ferns, have a dominant sporophyte generation that produces spores with a hard outer covering. After they are released and land in a hospitable environment, they can develop into new plants, which can make more spores. The adult plant in this case is called a sporophyte. Notice the round structures on the fronds from a fern plant. These are the spore cases. Each one contains many spores.
Seed plants, like the orchids we've been studying, have a dominant sporophyte stage. The sporophyte stage of seed plants is the plant as a whole or what we see. The flower contains the gametophyte parts of the plant that produces the gametes for reproduction. Diagram of Alternation of Generation in Plants
Note: For most plants, the sporophyte generation is the adult plant you are familiar seeing. For example, when you look at an oak tree you are seeing the sporophyte. SAS inSchool Web Activity
Instructions:
Printable copy of the Respond Sheet: Alternation of Generations Respond Sheet 7.03 Honors Reproduction of Plants
30 points To complete this activity:
Fern © National Park Services 2006, plant life cycle © FLVS 2006.
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