|
|
1. Describe the characteristics that organisms must posses to be part of the following kingdoms.
A. Animal
B. Monera
C. Protista
D. Fungi
E. Plant
F. Archaebacteria
A. To be considered an animal, you must fit the following characteristics. You must be motile, or mobile. You must be heterotrophic, meaning you can not produce your own food. You must be multi-cellular, and have eukaryotic cells, meaning they have a nucleus. Most reproduce sexually; a few can reproduce asexually. There are more then 1,000,000 animal species, from spiders, to elephants, to humans. Animals are also mobile.
B. The kingdom Monera is made up of prokaryotic organisms, which lack nuclei and other membrane-bound organelles. Monerans have a glycoprotein cell wall and are single-celled. Many Monerans live in aquatic and terrestrial habitats and obtain nutrients primarily from absorption. Other Monerans are autotrophic, producing food by either photosynthesis or chemosynthesis, such as Cyanobacteria. Most Monerans reproduce asexually, although members of some specie exchange genetic material. Scientists have identified only about 5,000 Moneran species. Bacteria is one of the most familiar Moneran organisms. Archaebacteria are a part of the Moneran kingdom but are simpler and should have their own classification.
C. The kingdom Protista is made up of eukaryotic organism that lack specialized tissue systems. To be a Protista, you must fit the following characteristic. You must be a single cell eukaryote, but you can live in colonies, such as kelp. You may be either autotrophic, such as algae. Or heterotrophic, such as protozoa's, which cause more death then any bacteria. You must have a chloroplast like structure, known as a Euglena. Protists may be unicellular or multicellular. They live in aquatic or moist habitats and obtain their food by ingestion, absorption, or photosynthesis. They reproduce sexually or asexually. More then 50,000 species have been placed in the kingdom Protista.
D. To be a fungi, you must posses the following characteristics. You must be heterotrophic. You must be multi-cellular. You must have a cell wall made of chitin. You must be eukaryotic. You must have digestive enzymes. You can either be parasitic, like athletes foot, or saprophytic, meaning you feed off of dead material. . Most species are terrestrial. They reproduce sexually and asexually.
E. To be a plant you must have these characteristics. You must be sessile, or immobile. You must be a multi-cellular, and eukaryotic. you must be autotrophic, and you must have cell walls made of cellulose. . Most plants are terrestrial. They reproduce sexually and asexually.
F. Archaebacteria are actually part of the kingdom Monera but they are simpler and should have their own kingdom. The cell walls and membranes of Archaebacteria are quite different from those of the eubacteria, and the way that Archaebacteria produce protein from their DNA is also different. Since Archaebacteria evolved before there was oxygen, Archaebacteria combine hydrogen with carbon dioxide, to form methane and get their energy out of that.
2. Compare the evolution of the above kingdoms with the geologic time scale.
Kingdom Monera
Kingdom Protista
Kingdom Fungi
Kingdom Plant
Kingdom Animal
3. How does the concept of phylogeny relate to the geologic time scale?
The geologic time scale and the phylogenic tree are very similar. Both start with the oldest and least complex organism and then work their way up to the newest and most complex creatures. Therefore, the geologic time scale and the phylogenic tree move through history in the same way.
4. Explain how and why phylogenic trees are drawn. What can be learned by studying them? Give examples.
Phylogenic trees are drawn to show the relationships between different species. They are drawn starting with the least complex and oldest organism, then branching out to sub-phylum's with new and more complex organisms. By studying a phylogenic tree, you can learn how closely related certain organisms are, how old and complex they are and if they share a common ancestry. You start out with a basic organism, such as a simple eukaryotic cell, and you can trace its evolvement into different sub-phylum's and eventually different species. On the phylogenic tree the branches that are the closest together have the closest relations of species. Knowing how species evolved and who their distant and new relatives are is helpful for humans. For instance, the reason we test new medical procedures on chimpanzees is that we know that they are closely related to humans because of the proven pathways of the phylogenic tree.
For instance, in the rain forest their was a plant called the Yew. It contained a substance called taxol used to treat cancer. Due to deforestation the Yew had almost been extinct. By examining a phylogenic tree, they found two other Yews, a Japanese Yew, and a European Yew. The Japanese Yew did not have the substance. The European Yew had a substance that was very similar. Through genetic engineering, they where able to alter that substance so it was the same as the original U’s substance, and it is used to treat cancer.
