Toad and Rat dissection
Materials and Safety/Ethical considerations: List materials used in the dissection Safety and hygiene equipment: Gloves Glasses Newspaper All benches were wiped Method: 1. A rat and a cane toad were dissected to compare their similarities and differences in anatomy structure. 2. Newspaper was laid out under the dissecting trays. 3. The external features of each animal was investigated and notes were collected. 4. The internal features of each animal were investigated and notes were collected. 5. Dissecting materials were placed into a container of Dettol. 6. The rat and toad were wrapped up into the newspaper and discarded in the bin.
Tables and aprons were sprayed and wiped down. Results – Include your table of observed notes (primary data), any diagrams or photos. Rat Toad External features White short hair- keeps the rat warm Little eyes- Has bad hearing Whiskers- To help guide the rat from running into things Long nose- Used to smell poison or other bad foods Short stubby legs Long tail- for balance No fur, moist skin- its environment is always wet Big eyes on the side of the head- used to see predators Small nose with hard shell around it Short strong legs Internal features Long small intestine Locomotion Short stumpy legs- To scatter quietly
Claws- To open and scratch objects Short strong legs- to jump Webbed feet- to swim through water Feedings Insects : maggots, flies and Discussion: Discuss the similarities and differences of the anatomy of the rat and the toad. This should include a discussion about size/colour/shape of external and internal features (this section is written using primary and secondary data making reference to your results section). In this dissection it was clear how the toad and rat were different, even though they did share some similarities. A difference that is clear is the difference of size between them.
The toad is larger and rounder, as its structure is larger to suit its environment. In the toads environment it is full of prey and water, if it was small it would be eaten straight away and the toad population would of died out. The rat on the other hand is quite small, because of this they are quite fast. This is for the reason that they fit inside little wholes and have to be quiet and fast moving to survive or the will kill them. The rat has a tail as is then able to keep balance whereas the toad is larger and can keep balance by its self. Another difference between these two animals is that their internal features are quite different.
As was shown the dissection, the rat’s small intestine is lengthy when stretched where as the toads small intestine is small in length but large in width. A similarity between the two animals that is quite obvious is that these two have ‘ Investigate and discuss comparative embryology making links to how these two animals have evolved from a common ancestor. Investigate and discuss comparative anatomy with reference to the pentdactyl limb discussed in class this term. Investigate and discuss how each animal has evolved through adaptations to be best suited to their natural habitat or environment.
Conclusion: a concise summary paragraph about what has been learnt and explained in your discussion. Bibliography: Class notes and dissections (please refer to the diary for the correct formatting of these references) Secondary data sightings Appendix: if you wish to include internal images from the internet of your animals these would be included as an appendix rather than placed in your result or discussion sections of the report. They would be referred to as Appendix 1, Appendix 2 and be mentioned in your discussion text.