Biology Standard 2, Objective 1

Biology Standard 2, objective 1

Multiple Choice a1. Which chemical elements would you expect to find in abundance in a living cell?

A. hydrogen, neon, argon B. carbon, oxygen, hydrogen C. iron, magnesium, calcium D. sodium, potassium, sulfur a2. What is the most common form hydrogen and oxygen are found in living things?

A. fats B. water C. protein D. DNA a3. How can the acronym “CHNOPS” help you remember the elements found in living things?

A. It stands for “children have not often played school”. B. It is the name of the most common chemical element. C. It is the chemical symbol of the 6 most common elements. D. It is a code that can be unlocked with a password. b4. What are the functions of lipid molecules?

A. provide molecules for body structures and enzymes B. contain genetic information that guides cell functions. C. provide “quick energy” when the body needs it. D. store energy and release it when it is needed. b5. Which of the following is a main component of enzymes and is responsible for the structure of cells and tissues?

A. lipid B. nucleic acid C. protein D. carbohydrate Use these simplified diagrams of macromolecules to answer the next three questions.

C-C-C-C-C-C

A B C D b6. Which structure represents a lipid molecule?

A. A B. B C. C D. D b7. What is the function of the molecule pictured on C?

A. store energy for future use B. carry genetic information C. act as an enzyme in chemical reactions D. provide “quick energy” for cells

60 50 40 30 20 10 0 carbohydrate lipid protein nucleic acid b8. This chart shows the percentage amount of macromolecules found in the cells of a body tissue. Which tissue type would this cell be from?

A. muscle B. fat C. nerve D. DNA c9. Eliminating wastes in urine takes advantage of which of water’s properties?

A. solvent B. capillary action C. heat capacity D. adhesion c10. Water is polar in nature. To be polar means to:

A. be very cold and difficult to warm up. B. freeze easily and boil rapidly C. have positive and negative charged ends D. have a low heat capacity

Answer the following two questions based on this experiment. An experiment is performed to see how plants respond to acid rain. Water plants are placed in water of varying pH measurements. The pH levels are 2.5, 6.0, 7.0, and 9.0. Each day, the health of the plants is measured by counting the leaves and recording the color. c11. Which pH is the best control for this experiment?

A. 2.5 B. 6.0 C. 7.0 D. 9.0 c12. If plants in the 2.5 and 9.0 pH range died, which conclusion is justified?

A. Plants do not grow well in acids. B. Plants do not grow well in bases. C. Plants are resistant to changes in pH. D. Plants do not grow well in extremes in pH. c13. What is the qualitative measurement in this experiment?

A. color of plants B. number of leaves C. number of plants D. pH of the water Each beaker is filled with the same amount of different liquids. The liquids have been drawn up into the tubes to the line shown. Answer the following questions based on the diagram of the tubes and your knowledge of the properties of water.

A. B. C. D. c14. Which substance has the most capillary action?

A. substance A B. substance B C. substance C D. substance D c15. Which substance demonstrates the least adhesion to the tube?

A. substance A B. substance B C. substance C D. substance D c16. Water helps living organisms maintain internal balance. The best example of this is when water

A. forms layers inside the cell. B. prevents large fluctuations in body temperature C. uses capillary action to move water to great heights D. helps small bugs stay afloat on the waters surface d17. A reaction in a cell can occur at lower temperatures and more rapidly because of which type of molecules?

A. enzymes B. carbohydrates C. fats D. vitamins Use this information to answer the next two questions:

Students perform an experiment with hydrogen peroxide (H2O2) and beef liver. They take the temperature of the H2O2 and then add a piece of the liver. The temperature rises 3 degrees Celcius and a gas is quickly given off that has the properties of oxygen. A control tube with H2O2 and no liver is unchanged. d18. What should the students conclude from these results?

A. Substances in the liver allowed the reaction to occur rapidly. B. The reaction occurred when air and hydrogen peroxide came in contact. C. The beef liver needed the H2O2 to maintain the functions of a living thing. D. The H2O2 has the same reaction with the liver as H2O (water) does. d19. What should the students expect to happen if they add additional hydrogen peroxide?

A. nothing, the enzymes in the liver have been used up. B. a slower reaction than the first one, some of the enzyme may remain. C. the same reaction as before. D. an entirely different reaction.

1. What are four common elements in a cell?

2. Outline the significance of water in biology. - include at least two specific properties of water - include how the structure of water lends to its importance

3. Explain why cells must maintain a stable internal temperature and why water is important in this maintenance.

4. Describe the function of carbohydrates, lipids, proteins and nucleic acids in cells. Answers:

1. B 2. B 3. C 4. D 5. C 6. D 7. B 8. A 9. A 10. C 11. C 12. D 13. A 14. D 15. A 16. B 17. A 18. A 19. C

Essay Sample answers:

1. Both reactions involve water in a chemical reaction. They are different because hydrolysis consumes water in the chemical reaction and dehydration releases it.

2. Water is important to biology as evidenced by its presence in a large percentage in all living things and the fact that it is generally given as a basic characteristic of cells, which are basic to life. Two of water’s specific properties are cohesion and adhesion. Cohesion is the fact that water molecules seek to form weak bonds with other water molecules. This characteristic leads to water’s insulatory properties, helping it to maintain homeostasis by regulating internal temperatures. Adhesion is the fact that water molecules seek to form weak bonds with other materials. This characteristic leads to water’s capillary action. This is important in water being able to move up thin membrane vascular tissue of cells in plants, helping vascular plants in the transport of water and dissolved materials throughout the plant.

3. Cells must maintain a stable internal temperature in part because proteins found in cells (especially enzymes) operate within a narrow range of temperatures. Too low of a temperature and proteins function too slowly. Too high of a temperature and proteins become denatured (their physical structure is broken down)and lose their ability to function as a result. Water is important in maintaining homeostasis because of its insulatory properties. It requires a large amount of energy gain or loss to change the temperature of water. Therefore anything that contains a large amount of water, including cells containing proteins, which make up all living things, benefit from water’s insulatory properties.

4. Carbohydrates supply cells with energy, lipids make up cell membranes and also store energy, proteins provide cell structure and make-up enzymes and nucleotides are the building blocks of DNA which carries genetic information.