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The Importance Of External Structures

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Teachers and professors ask students to do dissections to gain a better understanding of the anatomy of a subject and how it works. Students do dissections to get a hands-on experience that could be more efficient than a video or an image. A dissection allows the student to witness external and internal structures of an organism and see how the structures function together. Dissections also allow the students to see how species have evolved to better fit their environment (McNeil, 2017). 2. How can you differentiate between a male and female rat using external features? Using internal features? Explain the size of a typical rat litter using external structures of the female rat. Why are rat testicles so large? The differentiation between male and female rats on external features was the reproductive features of each rat. For the male rat, the large scrotal sacs were located at the base of the tail and the penis anterior to the anus. For the female rat, the vagina was externally located anterior to the anus and there were two rows of mammary papillae. Internally, the male rats have two testes, epididymis and vas deferens from the caudal end of the epididymis (http://www.publichealth). Internally, female rats have ovaries, which are posterior to the kidneys, oviduct, and a vagina. The number of nipples on a female explains the size of a typical rat litter. More babies can be fed because of the number of nipples on a female rat. Rats can reproduce up to 6 times a year

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