Cartilage, bone and fat (see connective tissues section of article)
Answer:
A. Commensalism because the flatworm benefits while the horseshoe crab doesn't but isn't affected.
B. Predator-prey since the shark is the predator and the seal is the prey.
C. Competition because the two males are fighting for the female.
Hope this helps :)
Answer:
Used as the primary source of energy in living organisms
Explanation:
Proteins are the main structural and functional molecules of the body. They make up hormones that are used in signaling, make up the structure of cells, immunoglobulins, carrier proteins, and etcetera. However, the main energy source of the cells is glucose (sourced from carbohydrates). Protein is metabolized as the last resort after glucose and fats. This is because protein breakdown has toxic nitrogenous byproducts (such as creatinine, ammonia, and urea) due to their amino group.
The answer is artery.
A blood vessel with a thick layer of smooth muscle and elastic fibers is artery. Even though both artery and veins are smooth muscle and elastic fiber. The difference is veins have valves, while arteries don't.
