171 Poster Incomplete
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Animal Diversity: An Investigation of The Digestive System Harvey Gill , Kevin, Francesca, Amanda EXPERIMENTAL DESIGN AND METHODS INTRODUCTION AND CONCEPTUAL BACKGROUND (Dissections) Discussion: (Pre-fixed Slides) References: Freeman, S. (n.d.). Biological science (Fourth ed.). The function of a digestive system is to essentially breakdown complex food particles/molecules and to absorb the macro/micro-nutrients that these molecules contain. Animals are heterotrophic organisms that require the ingestion of food particles; after ingestion of food, the digestive system abstracts the necessary organic carbon molecules needed to sustain life and waste products are ultimately separated as a result from this process (absorption). In dependence on the individualistic phyla of an organism, there is a rather significant variance between the digestive systems of differing animals; in essence both diploblast and triploblast organims are comprised of a certain degree of endoderm embryonic tissue, which gives rise to the digestive tract. The digestive tract consists of organ/organs that pass from the mouth to the anus, but certain organisms such as those belonging to the phylum platyhelminthes do not have a digestive tract, and rely on the mechanism of diffusion to obtain nutrients. Population selected: Predetermined slides of 5 digestive tracts of differing organism (a. Sponge b. Hydroid c. Planarian d. Roundworm e. Earthworm)were obtained and thoroughly observed; furthermore the digestive tract’s of both an Earthworm and Roundworm were examined via dissection. Methods: Predetermined/pre-fixed slides were obtained and the contents of each respective slide were analyzed through the use of dissection/compound microscopes. Dissection microscopes were correctly set up in accordance to the rules and regulations set by the California State University Fullerton’s Biological Science department: • Carry the microscope using both hands and hold the microscope in an upright position • Ensure that all the microscope parts are fully functional and set up under optimal conditions • Adjust magnification and use Kohler illumination to optimally observe specimen • Clean the microscope (parts/base) and return it to the correct positioning Dissection was carried out in compliance with rules and regulations set by the California State University Fullerton’s Biological Science department: • Obtain all the necessary tools to carry out the dissection: (dissection board, pins, scalpel, scissors, etc.) • Pin the respective organism that is to be dissected on the board (ensure that the organism is properly pinned so that no organs are ruptured) • For the earthworm (using a scalpel), cut along the dorsal side of the clitellum at segment 33 • For the roundworm (using a scalpel), cut from mouth to anus • Use the respective anatomical figures (descriptions) of each organism to identify the digestive tract Data analysis: Data was not quantifiable, and was instead gathered for comparative purposes. The Data is presented in the following Table (). See results. In regards to the digestive systems observed, it is evident there were clear evolutionary changes amongst the different phylum’s. For example, if comparing figure 1 and figure 4, we see that the digestive systems of these two groups of organisms are quite different, in fact it is observable that since sponges lack an anus (they have an incomplete digestive tract) and therefore utilize other means too absorb food (intracellular filter feeding). Overall, it can be assumed that the digestive system drastically changed over time to accommodate the specific needs of a specific animal. Fig. 1 a)Roundworm prior to dissection. A ruler (cm) is provided to scale the organism. b) Longitudinal dissection of a roundworm (Ascaris) to reveal internal structure Fig. 2 a) Earthworm prior to dissection. A ruler (cm) is provided to scale the organism. b) Longitudinal dissection of an earthworm to reveal internal structure.
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Animal Diversity: An Investigation of The Digestive System Harvey Gill , Kevin, Francesca, AmandaEXPERIMENTAL DESIGN AND METHODSINTRODUCTION AND CONCEPTUAL BACKGROUND(Dissections)Discussion: (Pre-fixed Slides)
References:Freeman, S. (n.d.).Biological science(Fourth ed.). The function of a digestive system is to essentially breakdown complex food particles/molecules and to absorb the macro/micro-nutrients that these molecules contain. Animals are heterotrophic organisms that require the ingestion of food particles; after ingestion of food, the digestive system abstracts the necessary organic carbon molecules needed to sustain life and waste products are ultimately separated as a result from this process (absorption). In dependence on the individualistic phyla of an organism, there is a rather significant variance between the digestive systems of differing animals; in essence both diploblast and triploblast organims are comprised of a certain degree of endoderm embryonic tissue, which gives rise to the digestive tract. The digestive tract consists of organ/organs that pass from the mouth to the anus, but certain organisms such as those belonging to the phylum platyhelminthes do not have a digestive tract, and rely on the mechanism of diffusion to obtain nutrients.
Population selected: Predetermined slides of 5 digestive tracts of differing organism (a. Sponge b. Hydroid c. Planarian d. Roundworm e. Earthworm)were obtained and thoroughly observed; furthermore the digestive tracts of both an Earthworm and Roundworm were examined via dissection.
Methods: Predetermined/pre-fixed slides were obtained and the contents of each respective slide were analyzed through the use of dissection/compound microscopes. Dissection microscopes were correctly set up in accordance to the rules and regulations set by the California State University Fullertons Biological Science department:Carry the microscope using both hands and hold the microscope in an upright position Ensure that all the microscope parts are fully functional and set up under optimal conditions Adjust magnification and use Kohler illumination to optimally observe specimen Clean the microscope (parts/base) and return it to the correct positioningDissection was carried out in compliance with rules and regulations set by the California State University Fullertons Biological Science department: Obtain all the necessary tools to carry out the dissection: (dissection board, pins, scalpel, scissors, etc.) Pin the respective organism that is to be dissected on the board (ensure that the organism is properly pinned so that no organs are ruptured) For the earthworm (using a scalpel), cut along the dorsal side of the clitellum at segment 33 For the roundworm (using a scalpel), cut from mouth to anus Use the respective anatomical figures (descriptions) of each organism to identify the digestive tract
Data analysis: Data was not quantifiable, and was instead gathered for comparative purposes. The Data is presented in the following Table (). See results. In regards to the digestive systems observed, it is evident there were clear evolutionary changes amongst the different phylums. For example, if comparing figure 1 and figure 4, we see that the digestive systems of these two groups of organisms are quite different, in fact it is observable that since sponges lack an anus (they have an incomplete digestive tract) and therefore utilize other means too absorb food (intracellular filter feeding). Overall, it can be assumed that the digestive system drastically changed over time to accommodate the specific needs of a specific animal.
Fig. 1 a)Roundworm prior to dissection. A ruler (cm) is provided to scale the organism. b) Longitudinal dissection of a roundworm (Ascaris) to reveal internal structureFig. 2 a) Earthworm prior to dissection. A ruler (cm) is provided to scale the organism. b) Longitudinal dissection of an earthworm to reveal internal structure.
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