Hall, Richard P. University of California, Los Angeles, California.
- Colonies and aggregates
- Nutritional requirements
- Life cycles
- Sexual activities
- Parasitic Protozoa
- Links to Primary Literature
- Additional Readings
A group of eukaryotic microorganisms traditionally classified as one of the five animal kingdoms. Although the name signifies primitive animals, some protozoa (phytoflagellates and slime molds) show enough plantlike characteristics to justify claims that they are plants. This apparent conflict may be reconciled to some extent by considering protozoa as descendants of microorganisms which preceded plants and animals. Such an assumption might account for Euglena gracilis, a green flagellate which can fix carbon dioxide (CO2) in light as algae do but, unlike algae, can also carry on a plantlike fixation in darkness. In addition, E. gracilis can fix carbon dioxide by pathways characteristic of animals. Inclusion of such metabolically unspecialized organisms, along with certain photoautotrophic chlorophyll-bearing species, might imply that the phylum is partly an arrangement for taxonomic convenience rather than a phylogenetically homogeneous group.
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 9000 highly qualified scientists and 43 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information