1. Imagine a nerve cell that measures 125 µm x 1 µm x 1 µm. Predict how its surface area-to- volume ratio compare with those in the project yesterday. Then calculate the ratio and check out your prediction. How does the endosymbiotic theory explains the evolution of eukaryotic cells? Antibiotics usually only effective against bacteria and kill them by reacting with their cell wall. Explain how it is possible that antibiotics do not destroy other cells.

2. Males afflicted with Kartagener’s syndrome are sterile because of immotile sperm, and they tend to suffer from lung infections. This disorder has a genetic basis. Suggest what the underlying defect might be. List organelles that you would expect to see in large numbers in the following cells: – Cells that specialize in water transport – Cells that specialize in motion – Cells that specialize in protein hormone production – Cells that specialize in steroid hormone production – Cells that specialize in detoxification

3. Do plants have mitochondria? Why or why not? Describe structural and functional distinctions between rough and smooth ER. Describe what the endomembrane system is and how it is an interconnected entity within the cell. Describe how the location of ribosomes is related to the type of protein that they make. Describe the path of a protein from the nucleus where the genetic information is stored for its production to its final destination outside of the cell. How do bacteria perform cellular respiration if they don’t have mitochondria and photosynthesis if they don’t have chloroplasts?

4. Explain how the structure of the Golgi apparatus fits to perform its function. Explain how the structure of the smooth ER fits to perform its function. Explain how the structure of microfilaments and microtubules fit to perform their functions. Describe the location and the general structure of the extracellular layer of cells. How does this structure fit to perform its function? How would an animal cell be impacted by the loss or depletion of an extracellular matrix? What would happen if plant cells did not have any plasmodesmata?

5. And one more really evil question on cell structure: The polypeptide chain that makes up a tight junction waves back and forth through the membrane four times, with two extracellular loops, and one loop plus short C-terminal and N-terminal tails in the cytoplasm. What would you predict about the types of amino acid side chains that make up the tight-junction protein?

6. Suggest a hypothesis to explain why the thylakoid membranes of chloroplasts resemble those of cyanobacteria. Contrast the cellular and DNA structures of prokaryotes and eukaryotes. Although mutations are rare, they can still provide considerable genetic variation in a short period of time into bacterial populations. Explain the reasons why. Distinguish among the three mechanisms that are used to transfer DNA from one bacterial cell to the next.

7. In a rapidly changing environment, which bacterial population would likely be more successful, one that includes individuals capable of conjugation or one that does not? Explain. If a nonpathogenic bacterium were to acquire resistance to antibiotics, could this strain pose a health risk to people? Explain. In general, how does DNA transfer among bacteria affect the spread of resistance genes? Explain how viruses introduce genetic variation in host bacteria. How has metagenomics contributed to our understanding of prokaryotic diversity?

8. Explain how Gram-positive and Gram-negative bacteria differ and how this difference influence potential treatment of bacterial diseases. Explain how quorum sensing can help bacteria sense the presence of bacteria of other species in their environment. How does it help with bacteria of the same species? If bacteria only reproduce asexually, how can they have such a wide genetic diversity? What are biofilms and how did they potentially contribute to the evolution of cells?

9. In a bag with a selectively permeable membrane you have a solution of 4 % salt and 2 % starch. The bag is permeable to salt but not to starch. You place this in a beaker with distilled water. Draw this system, determine the direction of the movement of various substances and determine the type(s) of transport used. Describe what happens with a plant cell when it is placed in a hypotonic solution.

10. What is the tonicity of this system above? What is moving through the membrane in what direction if the pores are about the size of glucose, but glucose can still fit through them? Describe the direction of water movement and final state of the cell if: – Plant cell is placed in a hypotonic solution – Animal cell is placed in a hypertonic solution – Plan cell is placed in a hypertonic solution – Animal cell is placed in an isotonic solution Has 4 M of sucrose and 2 M of glucose Has 2 M of sucrose and 4 M of glucose

11. A researcher discovered a new drug that treats lysosomal disorders. What kind of information would you collect to know if the drug is able to enter the cell membrane? The molar concentration of a sugar solution has been determined to be 0.3 M. Calculate the solute potential at 27 °C. Round your answer to the nearest hundredth. What is the water potential for this sample? If a cell is placed into this solution that has a Ψ = -0.5 bar, what is the tonicity of the cell compared to this solution? Predict the direction of water movement.

12. Calculate the water potential of a solution of 0.15 M sodium chloride in a beaker at 20 °C. If a cell with a Ψ = -0.8 MPa is put into this solution, what is the tonicity of the cell compared to the solution? What is the direction of water movement. At 20°C, a cell containing 0.6M glucose is in equilibrium with its surrounding solution containing 0.5M glucose in an open container. What is the cell’s Ψ P ?

13. In beaker B, what is the water potential of the distilled water in the beaker, and of the beet core? Which of the following statements is true for the diagrams above? A. the beet core in beaker A is at equilibrium with the surrounding water B. the beet core in beaker B will lose water to the surrounding environment C. The beet core in beaker B would be more turgid than the beet core in beaker A D. The beet core in beaker A is likely to gain so much water that its cells will rupture E. The cells in beet core B are likely to undergo plasmolysis.

14. Determine the type of transport required in the following cases: Glucose moves into the cell from a higher concentration area Oxygen gas moves into the cell Water moves into the cell Sucrose moves into the cell with the help of H+ ions. Sodium ions move out of the cell into a more concentrated area Large oil droplet moves into the cell. Cholesterol molecules move into the cell by using receptors. The cell releases a protein hormone.

15. Differentiate between positive and negative feedback mechanisms. Use examples of each. Describe how the temperature is regulated in an ectotherm in cold environments. Describe how the temperature is regulated in an endotherm in hot environments. Explain which organism an ectotherm or an endotherm would require more energy in cold weather. Describe how the blood glucose level is regulated if it goes below the normal levels. Describe how the blood glucose level is regulated if it goes above normal.

16. The movement of salt from the surrounding water to the blood of a freshwater fish requires the expenditure of energy. What type of transport is used? Why is that necessary? Why aren’t freshwater animals osmocomformers? Researchers found that a camel in the sun required more water when its fur was shaved off, although its body temperature was the same. What conclusion can you draw from the relationships between osmoregulation and insulation by fur?

17. What conditions would cause a cell to dehydrate? Name a benefit and a disadvantage of being an osmocomformer. If a freshwater fish is placed in sea water, it dies in several minutes. What could have caused its death? Complete the given review sheets

18. Draw and label the parts of the nephron. Label its functions on the picture. Differentiate between the different types of nitrogen wastes, their benefits and disadvantages in different organisms. How does alcohol affects the secretion of water with urine? If blood pressure in the afferent arteriole leading to the glomerulus decreased, how would the rate of blood filtration would be affected? Many medications make the epithelium of the nephron tubules less permeable. How would taking such a drug affect kidney output?

19. Conn’s syndrome is a condition caused by tumors of the adrenal cortex that secrete high amounts of aldosterone in an unregulated manner. What would you expect to be the major symptom of this disorder? Why could it be dangerous to drink a high volume of water in a short period of time? Insulinoma is a cancerous mass of pancreatic beta cells that secrete insulin but do not respond to feedback mechanisms. How would you expect an insulinoma to affect blood glucose levels and liver activity?