Thursday, February 5, 2009

Pterophytes



Characteristics:

Pterophytes are seedless, vascular plants.
They thrive in tropical areas, but are also known to occasionally live in temperate climates.

Pterophytes have a similar life cycle and reproduction pattern as the lycophytes, which would include the following:

  • Starting off with a spore that turns into a young gametophyte that then releases sperm and eggs(if bisexual) and is then fertilized during the haploid stage.

  • The egg then becomes a zygote and grows into a new sporophyte, and then the mature sporophyte releases the spores, within the diploid stage.]

  • The reproduction cycle occurs in two different methods, the homosporous spore production and the heterosporous spore production.

  • Homosporous spore production occurs when the sporangium in the sporophyll releases a single type of spore in a bisexual plant to fertilize itself.

  • Heterosporous spore production occurs when the megaspores and microspores, which are female and male gametophytes, are released and the sperm fertilizes the egg.


Examples:

-An image of the equisetum arvense(field horsetail),which has large air canals to carry more oxygen to roots, as it grows predominantly in waterlogged soil.