1. Science TAKS: Bell Ringers Prepared for the Scurry-Rosser High School Science Department Objective 2, B.04B Investigate and identify cellular processes including homeostasis, permeability, energy production, transportation of molecules, disposal of wastes, function of cellular parts, and synthesis of new molecules.

2. Important Definitions Homeostasis - The tendency of an organism or cell to regulate its internal conditions, such as the chemical composition of its body fluids, so as to maintain health and functioning, regardless of outside conditions. The organism or cell maintains homeostasis by monitoring its internal conditions and responding appropriately when these conditions deviate from their optimal state. –The maintenance of a steady body temperature in warm-blooded animals is an example of homeostasis. In human beings, the homeostatic regulation of body temperature involves such mechanisms as sweating when the internal temperature becomes excessive and shivering to produce heat, as well as the generation of heat through metabolic processes when the internal temperature falls too low. Permeability - The ability of a substance to allow another substance to pass through it, especially the ability of a porous rock, sediment, or soil to transmit fluid through pores and cracks. –the property of something that can be pervaded by a liquid (as by osmosis or diffusion)

3. #1) Which molecule provides most of the energy used to drive chemical reactions in cells? A. DNA B. RNA C. ATP D. ADP State Average: 25% correct

4. #2) When a sea urchin egg is removed from the ocean and placed in freshwater, the egg swells and bursts. Which of these causes water to enter the egg? F. Coagulation G. Sodium pump H. Active transport J. Osmosis State Average: 44% correct

5. #3) Which of these best explains why a freshwater aquarium would be a dangerous habitat for saltwater fish? A. The tissues of the saltwater fish would absorb too much acid. B. The organs of the saltwater fish would produce too much protein. C. The organ systems of the saltwater fish would consume too much energy. D. The cells of the saltwater fish would gain too much water. State Average: 46% correct

6. Kidneys and Dialysis Proteins and other large molecules cannot move through the membranes of healthy kidneys. The presence of large molecules in urine is an indication of unhealthy kidneys. Dialysis is a medical treatment that does the work for failing kidneys. In Dialysis, an artificial membrane impermeable to large molecules is used. Dialysis lowers protein levels in urine. #4) The info above contains some facts about kidneys and dialysis. Which of the following best explains why dialysis works? F. Dialysis reduces the size of proteins G. Proteins are dissolved by urine H. Dialysis filters proteins from solution J. Proteins transport membrane fragments State Average: 57% correct

7. #5) Why are photosynthesis and cellular respiration often considered opposites? A. Photosynthesis produces twice as many ATP molecules are cellular respiration does. B. Water is released during photosynthesis and consumed during cellular respiration. C. Photosynthesis occurs during the day, and cellular respiration occurs at night. D. Oxygen is produced during photosynthesis and used during cellular respiration. State Average: 61% correct

8. Use the information below and your knowledge of science to answer question #6. Louis Pasteur’s Experiment Like many other scientific breakthroughs, the discovery of immunization happened by accident. In 1880 Louis Pasteur was trying to protect chickens from cholera. To study the disease, Pasteur and his assistants gave injections of cholera bacteria to several groups of chickens. The chickens usually died from cholera after being injected with the bacteria. However, one group of chickens survived. Pasteur noticed that these chickens had been injected with a six-week-old batch of cholera bacteria. Pasteur’s assistants prepared new colonies of cholera bacteria and injected these chickens a second time. They also injected a group of chickens that had not been previously injected. Pasteur was surprised that the chickens that had been injected previously with the old bacteria remained healthy, while all the chickens in the second group became sick and died. This is how Pasteur came to discover that exposure to weakened pathogens can provide immunity from disease. The idea was later used to protect animals from other serious diseases. Today immunizations help protect people from any illnesses.

9. #6) Cholera-causing bacteria have a single flagellum that allows these bacteria to -- A. move B. reproduce C. excrete water D. produce sugar State Average: 58% correct

10. TAKS Question Set Answers #1 C #2 J #3 D #4 H #5 D #6 A