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Lab 1
Giardia
lamblia
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| Giardia
lamblia |
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| ‹ Diplomonadida & Parabasala › |
| Diplomonads |
| Diplomonads are single celled organisms with two haploid nuclei and no mitochondria. An example of a diplomonad is Giardia lamblia, a human intestinal parasite that you have viewed in lab. This protozoan is usually transmitted in water infested with Giardia in it's cyst form. It can also be transmitted from other animals (mostly by infecting water), making Giardia zoonotic. Some distinguishing features of Giardia lamblia are it's two nuclei (positioned in the middle of the tear-shaped body) and multiple flagella (all congregated at the posterior end). |
| Links: |
| http://martin.parasitology.mcgill.ca/jimspage/biol/giardia.htm http://www.biosci.ohio-state.edu/~parasite/giardia.html |
| Parabasalids |
| Parabasalids are similar to diplomonads in that they lack mitochondria, but do not have separate nuclei. An example of a parabasilid is Trichomonas vaginalis, a human vaginal parasite that you have viewed in lab. |
| Links: |
| http://medlib.med.utah.edu/parasitology/tvagim.html |
| ‹ Euglenozoa › |
| Euglenozoans are unicellular (usually) organisms that are autotrophic (photosynthesis), heterotrophic (absorption from environment), or mixotrophic (both). Euglenozoans come in two general forms: euglenoids and kinetoplastids. |
| Euglenoids |
| An example of a euglenoid is Euglena, a common inhabitant of pond water or other places rich in organic waste. It has a single flagella that it uses for movement and light reception. A distinguishing feature found in Euglena is that it is mixotrophic, meaning it can display autotrophy or heterotrophy depending on what the environment's current conditions are. |
| Kinetoplastids |
| Kinetoplastids are euglenozoans that are symbiotic, meaning they live in relation to another organism in a mutualistic relationship. Some kinetoplastids are pathogenic, causing diseases such as african sleeping sickness (Trypanosoma brucei), Chaga's disease (Trypanosoma cruzi), and leishmaniasis (Leishmania spp.). What makes kinetoplastids unique is the presence of a kinetoplast, which houses extranuclear DNA. |
| Links: |
| http://www.tulane.edu/~wiser/protozoology/notes/kinet.html |
| ‹ Alveolata › |
| Alveolata is composed of three main groups: the dinoflagellates, the apicomplexans, and the ciliates. All apicomplexans are parasites, and exclusively in vertebrate animals. The dinoflagellates and the ciliates are mostly free-living organisms, with some being parasitic. Alveolates have membrane-bound cavities called alveoli, the function of which is uncertain. |
| Dinoflagellates |
| Dinoflagellates have the distinction of being the only group of Alveolata that have flagellum (hence the name). They are often photosynthetic (autotrophic), but there are some that eat other organisms (heterotrophic); some even have the ability to do both, similar to Euglena. They can reproduce both sexually and asexually, which is usually based on what stage they are in during their complex life cycle. |
| Links: |
| http://www.geo.ucalgary.ca/~macrae/palynology/dinoflagellates/ |
| Ciliates |
| Ciliates are a group of Alveolata distinguished by tiny hair-like cilia, used for locomotion. They exist in freshwater and marine environments, and come in a wide variety of sizes. All ciliates possess two distinct types of Nuclei; the macronucleus (which dictates general "day to day" activities of the cell) and the micronucleus (which contains chromosomes and is involved in reproductive processes). |
| Links: |
| http://www.microscopy-uk.org.uk/mag/wimsmall/cilidr.html http://micrographia.com/specbiol/protis/cili/cili0100.htm |
| Apicomplexans |
| Apicomplexans are parasitic protozoans belonging to the phylum Apicomplexa. They lack locomotion-inducing appendages, as do most parasites. What makes apicomplexans parasitic is a complex of organelles designed to penetrate specific host cells and tissue, all of which are located at the pinnacle of the apicomplexan cell. They also lack contractile vacuoles, structures important in water balance (you should be able to see these on the Paramecium). An interesting trait of apicomplexans is their ability to have an alternation of generations, meaning that in it's life cycle apicomplexans can also reproduce sexually and asexually. Sexual reproduction occurs directly before spore production, and asexual reproduction is through binary fission. This will be talked about more thoroughly in Lab 2 and class. An example of Apicomplexa are Plasmodium (which you looked at in lab), the genus responsible for malaria. |
| Links: |
| http://www.ucmp.berkeley.edu/protista/apicomplexa.html |
| ‹ Stramenopila › |
| The clade Stramenopila includes several heterotrophic groups as well as a few photosynthetic ones (a.k.a. autotrophic). Although this clade is very diverse (since it can include both uni- and multi-cellular organisms), all members of Stramenopila have numerous fine, hair like projections on the flagella (if they possess flagella). Some examples of organisms classified within Stramenopila include Diatoms (which you looked at in lab), brown seaweed such as kelp, golden algae, and saprozoic (meaning they feed off of dead or decaying matter) and parasitic water molds. |
| Links: |
| http://www.cals.ncsu.edu/course/zo150/mozley/domkingd.html |
| Diatoms |
| Diatoms are autotrophic
unicellular members of Stramenopila. They are found in both freshwater and
marine environments, and are also able to withstand a wide range of pH,
organic pollution and temperature. Cells occur singly or in colonies, some
of which are visible to the naked eye. All mature diatoms lack flagella,
but their gametes may be either amoeboid or flagellated.
Two major groups of Diatoms are recognized: the centric (Order Centrales),
which possess radial symmetry, and the pennate (Order Pennales), which
possess bilateral symmetry. Centric diatoms appear circular when viewed
from the top while pennate diatoms appear cigar shaped. |
| Links: |
| http://www.calacademy.org/research/diatoms/overview/introduction.html |
| ‹ Rhodophyta › |
| Most members of this clade (most commonly called red algae) are macroscopic and muticellular. Organisms within this clade appear red because of a pigment that reflects red light and absorbs blue light. Because blue light penetrates water to a greater depth than light of longer wavelengths, these pigments allow red algae to live and photosynthesize at somewhat greater depths than most other algae. Another differentiating characteristic is that unlike some of the brown algae, none of the red algae achieve great size (none are longer than 1 meter). |
| Links: |
| http://www.ucmp.berkeley.edu/protista/rhodophyta.html |
| Porphyra |
| This type of red algae is commonly referred to as “nori”. It is commonly found in Asian foods, which has led to a huge “nori” industry in Japan. The dried seaweed wrapping of Japanese sushi is Porphyra. Normally Porphyra is used for sushi and other foods because it lacks cellulose in its cell wall, making it easier for us to digest. |
| Links: |
| http://www.mbari.org/~conn/botany/reds/lisa/consume.htm |
| Bactrachospermum |
| Although this is “red algae”, it does not appear red at all. The color may be viewed as a dark brown or a deep turquoise. According to some, Bactrachospermum contains chemical components peculiar to Rhodophyta, which could contribute to its color difference. The main axis of the plant is composed of many layers of cells with whorls of branches, giving a beaded appearance. The plant has a slippery mucous layer surrounding it, making the gathering of samples quite difficult. |
| Links: |
| http://www.microscopy-uk.org.uk/mag/artmay99/gbalgae.html http://www.lifesciences.napier.ac.uk/algalweb/acidrhodo.htm |
| Nemalion |
| This type of algae is also different than most types of Rhodophyta. It is slender and sometimes branched, and considered worm-like in appearance. They reside on rocks, especially where there is very active water. It can appear to be reddish or purple-brown while growing. |
| Links: |
| http://seaweed.ucg.ie/descriptions/Nemhel.html |
| ‹ Chlorophyta › |
| This “green algae” is the most diverse group of algae, with over 7,000 species growing in a variety of different environments. Like plants, members of the Chlorophyta group contain two types of chlorophyll, which they use to undergo photosynthesis. But unlike plants, they are primarily aquatic. Because they are aquatic and can manufacture their own food, they are considered “algae”, but they do not really share many other characteristics with other types of algae. All of this supports the popular hypothesis that plants evolved from green algae. |
| Links: |
| http://www.ucmp.berkeley.edu/greenalgae/greenalgae.html |
| Spirogyra |
| Spirogyra is a filamentous green alga that lives in almost every pond or ditch. At the end of the summer, this organism can grow to such huge numbers that it can form a thick scum on the surface of the water. Not many people know what beauty lies beneath this shapeless mass. Its chloroplasts are arranged beautifully, by running throughout the cell in a spiral. |
| Links: |
| http://www.microscopy-uk.org.uk/mag/art98/spirog.html |
| ‹ Mycetozoa › |
| This group of organisms represents some of the most unique, since they possess both characteristics of both animals and fungi. In the trophic (feeding) stage, the slime mold feeds on bacteria, spores and other organic matter. These organisms in the feeding stage are most often found under the bark of decaying logs or between layers of leaf litter. These may appear white or bright red, orange or yellow. When the food supply is exhausted or other unfavorable conditions occur, the plasmodium changes, taking on the appearance of a fungus. These structures contain the reproductive spores, which, when released, germinate and begin the life cycle again. |
| Physarum |
| Physarum is representative of the true slime molds. It's characterized by a plasmodium stage: a creeping multinucleate mass of protoplasm with no cell walls. In contrast to other organisms, Physarum is easily detected in the field and may be collected in the plasmodium or sporophore stage. |
updated 3-12-06