The inside surface area is shaped in a crescent. It consists of a spiral valve which is made up of the small intestine. Although the dogfish shark has a relatively short small intestine compared to other animals, therefore, the spiral valve allows for a more compact form of the small intestine.
Hence, this structure provides maximum surface area over a relatively short distance in order to make the absorption of nutrients efficient achieved from the food, the sharks had from eating different sea animals.
Polygenic inheritance is determined by multiple Genes <span>located at different loci on different chromosomes.
Polygenic inheritance happens when an individual posses quantitative traits that become a variation compared to the parent's traits.
This phenomenon happens due to the combination of two or more genes that resulted in the characteristics that considered as the combination of both parents' characteristic.
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Carolus Linnæus
<span> Taxonomy, responsible for many scientific classifications and influences in various field of life sciences or biology. Evidences that Taxonomy uses to group or categorizes species range from </span><span><span>
1. </span>"Fossil Records</span> <span><span>
2. </span>Comparative anatomy</span> <span><span>
3. </span>Comparative embryology</span>
4. Biochemical information <span><span>
5. </span>Cellular structure</span> <span><span>
6. </span>Behavior</span>"
<span>We also suggest that taxonomy has played various roles mainly in many aspects in Zoology, Botany, Anatomy and Physiology –aspects that include animal and human structures and functions. As the biotic community is so diverse it is classified to Biodiversity and the existence of properly assorting by set standard.<span> </span></span>
B. Stems absorbed water and minerals from soil
Hope this helps! :)