110 likes | 182 Views
Anthocerophyta (Hornworts). Block 5 4/6/09 Haley McKee- Image research and development Brianna Powers- Product representative and technical support Stephie Peters- Text research and development. Habitat. Antherocerophyta Appeared in the late Cretaceous period in the Mesozoic era
E N D
Anthocerophyta (Hornworts) Block 5 4/6/09 Haley McKee- Image research and development Brianna Powers- Product representative and technical support Stephie Peters- Text research and development
Habitat • Antherocerophyta • Appeared in the late Cretaceous period in the Mesozoic era • Found in tropical rain forests • Lives in damp soils or on rocks in tropical and warm temerate regions
Long Term Adaptations • Simplest plant to develop a cuticle • Cellular jacket surrounds the sperm and egg to hold in moisture • They have large gametophytes that do not depend on the sporophytes for nutrition • Hornworts have developed rhizoids which are root like parts use for anchoring
Alternation of Generations Haploid Male and female gametophytes Dominant life cycle stage Diploid
Morphology sporophyte (Consists of pseudoelaters) • The best way to distinguish a hornwort (especially from a liverwort or fern gametophyte) is to look at the plant under a low-power microscope; hornworts will generally have a single large chloroplast per cell. near-basal meristem gametophyte
Fertilization • Plants are coasted with a thin film of water and chemical attractants that draw sperm toward the archegonia to fertilize egg. • Need water to reproduce!
Gametophyte and Sporophyte • Gametophyte is also called the thallus • A single thallus can produce multiple sporophytes • Once sporophyte is formed it continues to grow just above the base • If conditions aren’t suitable for the gametophyte the sporophyte will stop growing • Sporophytes can photosynthesize but they depend heavily on the gametophyte’s carbon supply • A sporophyte cannot survive without the gametophyte
Diversity • There are 330 known species • Habitats are located in moist areas • They can range from tropical forests to swamps • Hornworts can float freely in water or attach themselves to rocks and soil
Benefits • Bryophytes had been the prevalent vegatation in the first 100 million years in terrestrial communities. • Scattered all throughout the world because of the easily traveling sperm. • Hornworts are seen as pests due to the fact that they grow easily and overtake water areas.
Citations • J. Hyvonen and S. Piippo. 1993. Cladistic analysis of the hornworts (Anthocerotophyta). • J. Hattori Bot. Lab. 74: 105-119. • P. Kenrick. 1994. Alternation of generations in land plants: new phylogenetic and palaeobotanical evidence. Biol. Rev. 69: 293-330. • McCubbin. PLANT DIVERSITY I: THE ORIGIN OF PLANTS AND COLONIZATION OF THE LAND. Retrieved April 09, 2009 from . http://74.125.47.132/search?q=cache:aGhWR30AXcgJ:www.slic.wsu.edu/bios/biol106/Lecture06notes.pdf+anthocerophyta+when+plants+are+coated+with+a+thin+of+water&cd=1&hl=en&ct=clnk&gl=us. • Starr, L. (2003). Biology Concepts and Application. Wadsworth Group. • (April 8, 2009). Hornwort. Retrieved April 13, 2009 from Nelson City Council. http://www.nelsoncitycouncil.co.nz/environment/-natural/pests/pest-directory/total/hornwart.htm. • hornwort. ( 2009). In Encyclopædia Britannica. Retrieved April 6, 2009, from Encyclopædia Britannica Online: http://search.eb.com/eb/article-9041094