52. This protist is a member of the genus, Euglena. It maintains homeostasis through its contractile vacuoles which expells excess water. Active transport uses cell energy to move materials of lower concentration to higher concentration. Passive transport allows substances to move across membranes without any input of energy from the cell.
51. This is a paramecia. I calculated the magnification by using a microscope that by itself had a 10X magnification and I used the addition magnification setting of 40X. I know that 10X4= 400, therefore 400X magnification.
68. Crab, crayfish, and lobster all have teeth in their stomach. This is called a gastric mill. With this digestive system, food passes through the esophagus to the stomach where the teeth made of chitin and calcium carbonate grind the food into a paste. Here is a picture of sushi with crab inside of it. Or, according to the label, "imitation crab".
38. A sponge is asymmetrical. Well this one comes from the kitchen sink rather than the Ocean floor, but I hope it still works.
