2. Eating a sweet potato provides energy for human metabolic processes. The original source of this energy is
    the energy   (1.) in protein molecules stored within the potato   (2.) made available by photosynthesis
    (3.) from starch molecules absorbed by the potato plant  (4.)  in vitamins and minerals found in the soil
 
 

3. A small green plant was placed in a flask as shown      in the diagram. A sensor that measures the      CO2 content of the air in the flask was inserted,      and then the flask was sealed with a rubber      stopper. The other end of the sensor was      connected to a computer to monitor and record      CO2  levels in the flask over a period of time.     For part of the time the flask was placed in bright      light and for part of the time it was placed in      total darkness.      The accompanying graph shows data that      were recorded by the sensor over a period of time.     Based on the given information and your      knowledge of biology, which condition most      likely produced the effect on CO2 level over the      first 23 minutes?      (1.) The light was on for the entire 23 minutes.      (2.) The light was off at the start and turned on             after 10 minutes.      (3.) The light was off for the entire 23 minutes.      (4.) The light could have been either on or off             because it would have had no effect on the             CO2 level.    4.  Based on the given information and your       knowledge of biology, which process most       likely caused the change in CO2 level in the       flask over the last 37 minutes?       (1.) photosynthesis  (2.) active transport       (3.) respiration   (4.) circulation

5. Which statement regarding the functioning of the cell membrane of all organisms is not correct?
    (1.) The cell membrane forms a boundary that separates the cellular contents from the outside environment.
    (2.) The cell membrane forms a barrier that keeps all substances that might harm the cell from entering the cell.
    (3.) The cell membrane is capable of receiving and recognizing chemical signals.
    (4.) The cell membrane controls the movement of molecules into and out of the cell.

6. Every single-celled organism is able to survive because it carries out   (1.) metabolic activities
    (2.) heterotrophic nutrition  (3.) autotrophic nutrition  (4.) sexual reproduction
 

7. The diagram at the right illustrates a      biochemical process that occurs in organisms.     The substance labeled "catalyst" is also known as     (1.) a hormone   (2.) an antibody     (3.) an enzyme   (4.) an inorganic compound

8. Which phrase best describes cellular respiration, a process that occurs continuously in the cells of organisms?
    (1.) removal of oxygen from the cells of an organism
    (2.) transport of materials within cells and throughout the bodies of multicellular organisms
    (3.) conversion of light energy into the chemical bond energy of organic molecules
    (4.) changing of stored chemical energy in food molecules to a form usable by organisms

9. What happens to certain nutrient molecules after they pass into muscle cells?
     (1.) They are replicated in the nucleus. (2.) They are changed into tissues and organs in the cytoplasm.
     (3.) They are acted on by enzymes and release the energy they contain.
     (4.) They enter chloroplasts, where they can absorb light energy.
 

10. A student designed an investigation to determine        the effect of temperature on the rate of        seed germination. The student placed moist        filter paper in each of four culture dishes. Ten        bean seeds were placed on the filter paper in        each dish. The four dishes were numbered        and placed in the dark at different temperatures        as follows: Dish 1: 10°C, Dish 2: 15°C,        Dish 3: 20°C, Dish 4: 25°C. The total number        of germinated seeds in each culture dish was        counted each day for two weeks.      Which data table is best for recording the results       of this investigation?  (1.) (1)  (2.) (2)  (3.) (3)      (4.) (4)

11. Feedback mechanisms are best described as processes that help  (1.) reduce hormone levels to below
      normal in the blood   (2.) directly control muscle contraction in the leg   (3.) destroy hormones in the blood
      (4.) keep body conditions near a normal, steady state

12. People with AIDS are unable to fight multiple infections because the virus that causes AIDS
      (1.) weakens their immune systems  (2.) attacks muscle tissue  (3.) produces antibodies in their blood
      (4.) kills pathogens
 
 

13. Which graph of blood sugar level over a        12-hour period best illustrates the concept        of dynamic equilibrium in the body?       ( 1.) (1)    (2.) (2)   (3.) (3)  (4.) (4)

14. Which statement accurately compares cells in the human circulatory system to cells in the human nervous
      system?  (1.) Cells in the circulatory system carry out the same life function for the organism as cells
      in the nervous system.  (2.) Cells in the nervous system are different in structure from cells in the
      circulatory system, and they carry out different specialized functions.  (3.) Cells in the circulatory
      system are identical in structure to cells in the nervous system.  (4.) Cells in the nervous system
      act independently, but cells in the circulatory system function together.
 

15. The accompanying diagram shows the        interaction between blood sugar levels        and pancreatic activity.   This process is an        example of        (1.) a feedback mechanism              maintaining homeostasis        (2.) the digestion of sugar by insulin       (3.) an immune system responding to              prevent disease        (4.) the hormonal regulation of gamete production

16. To test the effect of hormones on plant growth, six potted plant seedlings of the same species were
      measured and then sprayed with auxin (a growth hormone). After four weeks of growth under ideal
      conditions, the plants were measured again. To set up a proper control for this experiment, the
      investigator should   (1.) spray the same plants with different amounts of auxin
      (2.) wash the auxin off three of the plants after two weeks  (3.) spray auxin on six plant seedlings
      of the same species and grow them in the dark for four weeks   (4.) grow another six plant seedlings
      of the same species under the same conditions, spraying them with distilled water only
 

17. The diagram shown represents part of a life         process in a leaf chloroplast.        If the process illustrated in the diagram is         interrupted by a chemical at point X, there would         be an immediate effect on the release of        (1.) chlorophyll  (2.) carbon dioxide        (3.) nitrogen   (4.) oxygen

18. In an investigation to determine the change in heart rate with increased activity, a biology teacher
      asked students to take their pulses immediately before and immediately after exercising for 2 minutes.
      The data showed an average heart rate of 72 beats per minute before exercising and 90 beats per minute
      after exercising. If a valid conclusion is to be made from the results of this investigation, which assumption
      must be made?   (1.) In most students, the average heart rate is not affected by exercise.
      (2.) Each student exercised with the same intensity.   (3.) Exercise causes the heart rate to slow down.
      (4.) The heart rate of each student goes up 18 beats after jogging for 2 minutes.

19. Tomato plants in a garden are not growing well. The gardener hypothesizes that the soil is too acidic. To test
      this hypothesis accurately, the gardener could   (1.) plant seeds of a different kind of plant
      (2.) change the pH of the soil   (3.) move the tomato plants to an area with less sunlight
      (4.) reduce the amount of water available to the plant
 

20. Base your answer on the accompanying        diagram illustrating one type of        cellular communication and on your knowledge        of biology.       If a stimulus is received by the cells at A, the cells        at E will most likely use energy obtained from        a reaction between   (1.)  fats and enzymes        (2.) glucose and oxygen       (3.) ATP and pathogens        (4.) water and carbon dioxide

21. A glucose-tolerance test was conducted to observe the effect of time on glucose concentration in the blood.  An animal was fed 10 ml of glucose solution. At five different times after the ingestion of the solution, the blood glucose concentration was determined, and the results were recorded in the data table shown.   The change in glucose concentration in the blood between 0 and 30 minutes was probably due to     (1.) the liver releasing glucose into the small intestine   (2.) the synthesis of glucose from starch (3.) glucose being absorbed from the digestive system   (4.) glucose being used for cellular respiration

22. The mass of some corn plants at the end of their growth period was 6 tons per acre. Most of this mass
      was produced from   (1.) water and organic compounds absorbed from the soil
      (2.) minerals and organic materials absorbed from the soil   (3.) minerals from the soil and oxygen
      from the air   (4.) water from the soil and carbon dioxide from the air

23. Communication between cells is affected if there is decreased ability to produce
      (1.) digestive enzymes and gametes   (2.) hormones and nerve impulses
      (3.) antibodies and chloroplasts   (4.) antibiotics and guard cells

24. An iodine test of a tomato plant leaf revealed that starch was present at 5:00 p.m. on a sunny afternoon in
      July. When a similar leaf from the same tomato plant was tested with iodine at 6:00 a.m. the next morning,
      the test indicated that less starch was present. This reduction in starch content most likely occurred
      because starch was   (1.) changed directly into proteins  (2.). transported downward toward the
      roots through tubes   (3.)  transported out of the leaves through the guard cells
      (4.) changed into simple sugars
 
 

25.   The accompanying diagram represents movement          of a large molecule across a membrane.         Which process is best represented in this diagram?         (1.) active transport  (2.) protein building         (3.) diffusion  (4.) gene manipulation

26. A characteristic of hormones and enzymes that allows them to work effectively with other organic molecules
      is their  (1.) specific shape  (2.) concentration of carbon and hydrogen atoms  (3.) small size
      (4.) high-energy bonds

27. Luciferin is a molecule that, when broken down in fireflies, produces heat and light. The rate at which luciferin
      is broken down in cells is controlled by  (1.) a carbohydrate  (2.) an enzyme  (3.) a simple sugar
      (4.) a complex fat

Base your answers to questions 28 and 29 on the information below and on your knowledge of biology.

      A student completed a series of experiments and found that a protein-digesting enzyme
      (intestinal protease) functions best when the pH is 8.0 and the temperature is 37°C. During an experiment,
      the student used some of the procedures listed below.

Procedure

28.   Which two procedures would most likely cause a decrease in the rate of protein digestion?
         (1.) A and D   (2.)  C and D  (3.) B and C   (4.) A and E

29.   Which procedure would have the least effect on the rate of protein digestion?
        (1.) A   (2.) C   (3.) D   (4.)  E

30.   Allergic reactions are most closely associated with  (1.) the action of circulating hormones
        (2.) immune responses to usually harmless substances  (3.) a low blood sugar level
        (4.) the shape of red blood cells
 

Use the diagram at the right and your knowledge of biology to answer question 31 which follows.

31. A student hypothesized that lettuce seeds would not germinate (begin to grow) unless they were covered
      with soil. The student planted 10 lettuce seeds under a layer of soil and scattered 10 lettuce seeds on top of
      the soil. The data collected are shown in the table preceding this question.

      To improve the reliability of these results, the student should   (1.)  conclude that darkness is necessary
      for lettuce seed germination  (2.) revise the hypothesis  (3.) conclude that light is necessary for lettuce
      seed germination   (4.)  repeat the experiment using a larger sample size

32. Microbes that enter the body, causing disease, are known as  (1.) pathogens  (2.) enzymes
      (3.) antibodies   (4.) hosts

33. An experimental design included references from prior experiments, materials and equipment, and
      step-by-step procedures. What else should be included before the experiment can be started?
      (1.) a set of data  (2.) safety precautions to be used
      (3.) a conclusion based on data   (4.) an inference based on results

34. ATP is a compound that is synthesized when  (1.) chemical bonds between carbon atoms are formed
      during photosynthesis   (2.) energy stored in nitrogen is released, forming amino acids
      (3.) energy stored in chemical bonds is released during cellular respiration
      (4.) digestive enzymes break amino acids into smaller parts

35. The current knowledge concerning cells is the result of the investigations and observations of many scientists.
      The work of these scientists forms a well-accepted body of knowledge about cells. This body of knowledge
       is an example of a   (1.) hypothesis  (2.) theory  (3.) controlled experiment  (4.) research plan

36. The ability of certain hormones to attach to a cell is primarily determined by the
      (1.) receptor molecules in the cell membrane   (2.) amount of DNA in the cell
      (3.) proteins in the cytoplasm of the cell   (4.) concentration of salts outside the cell

37. In a cell, all organelles work together to carry out  (1.) diffusion  (2.) information storage
      (3.) active transport   (4.) metabolic processes

38.  An increase in the level of insulin in the blood would most directly result in
       (1.) a decrease in the amount of glucose in the blood
       (2.) an increase in the amount of fat in cells
       (3.) a decrease in the amount of protein in the blood
       (4.) an increase in the amount of carbon dioxide in cells

39. Which statement does not identify a characteristic of antibodies?
      (1.) They are produced by the body in response to the presence of foreign substances.
      (2.) They are nonspecific, acting against any foreign substance in the body.
      (3.) They may be produced in response to an antigen.
      (4.) They may be produced by white blood cells.
 

40. A student placed a solution of glucose and yeast in        a vacuum bottle and sealed it with a        two-hole stopper as shown in the diagram at the       right.   The temperature of the        yeast-glucose solution increased gradually with        time, and the color of the indicator was        observed and recorded throughout a 2-day period.       The purpose of the investigation was most likely to       (1.) study the relationship between temperature        and pressure  (2.) show that proteins are        produced by yeast  (3.) demonstrate the release        of energy by a chemical process        (4.) study autotrophic nutrition in yeast

Use the information below and your knowledge of biology to answer questions 41 and 42 which follow.
 

41. According to the data in the accompanying table,        as the temperature increases, the rate of        respiration of the sunfish      (1.) increases steadily (2.) increases, then decreases      (3.) decreases steadily  (4.) decreases, then increases 42. If a line graph was constructed from the data in        the accompanying table, which title would        be appropriate for this graph?       (1.) The Effect of Temperature on Rate               of Respiration in Sunfish        (2.) The Relationship Between Temperature               and Dissolved Oxygen       (3.) The Effect of Gill Movement on Rate               of Respiration in Sunfish        (4.) The Relationship Between Sunfish               Population and Temperature Change               in Freshwater Habitats

43. Diagrams, tables, and graphs are used by scientists mainly to  (1.) design a research plan for an experiment
      (2.) organize data  (3.) test a hypothesis  (4.)  predict the independent variable
 

44. The accompanying diagram shows two setups        that were used to study bacterial growth. Each        setup initially contained an equal number of        the bacterium E. coli in different        carbohydrate solutions. After one hour,        a 1-ml sample was drawn from each tube        and analyzed. The number of bacteria found in        the sample from test tube 1 was higher than        the number in test tube 2.  Which        conclusion regarding this investigation is not valid?       (1.) All bacteria grow best in a solution of glucose.        (2.) The type of sugar solution will make a               difference in the rate of growth of E. coli.       (3.) E. coli grows better in a 10% solution of               glucose than in a 10% solution of sucrose.        (4.) The rate of growth of E. Coli depends on               the type of carbohydrate present.

45. The effect of pH on a certain enzyme is shown in         the graph at the right.   At what pH would         the enzyme be most effective?           (1.) above 10 3.   (2.) between 5 and 7        (3.) between 8 and 10  (4.) below 5

 46.  Which words best complete the lettered blanks in the two sentences below?

Organic compounds, such as proteins and starches, are too A to diffuse into cells. Proteins are digested into B and starches are digested into C .
(1) A—large, B—simple sugars, C—amino acids
(2) A—small, B—simple sugars, C—amino acids
(3) A—large, B—amino acids, C—simple sugars
(4) A—small, B—amino acids, C—simple sugars

47.  Which sequence of terms is in the correct order from simplest to most complex?
(1) cells, tissues, organs, organ systems 
(2) tissues, organisms, cells, organ systems
(3) cells, tissues, organ systems, organs
(4) organs, organisms, organ systems, cells

48. While viewing a slide of rapidly moving sperm cells, a student concludes that these cells require
a large amount of energy to maintain their activity.   The organelles that most directly provide this
energy are known as  (1) vacuoles (2) chloroplasts (3) ribosomes (4) mitochondria

49.  In nature, during a 24-hour period, green plants continuously use  (1) carbon dioxide, only 
(2) both carbon dioxide and oxygen (3) oxygen, only  (4) neither carbon dioxide nor oxygen

50.  Which statement describes all enzymes?  (1) They control the transport of materials.
(2) They provide energy for chemical reactions.  (3) They affect the rate of chemical reactions.
(4) They absorb oxygen from the environment. 

51. Organisms undergo constant chemical changes as they maintain an internal balance known as
(1) interdependence  (2) synthesis  (3) homeostasis (4) recombination

52.  Scientific studies have indicated that there is a higher percentage of allergies in babies fed formula containing cow’s milk than
in breast-fed babies. Which statement represents a valid inference made from these studies?  (1) Milk from cows causes allergic reactions
in all infants.  (2) Breast feeding prevents all allergies from occurring.  (3) There is no relationship between drinking cow’s milk and
having allergies.  (4) Breast milk most likely contains fewer substances that trigger allergies.

53.  A student observes that an organism is green. A valid conclusion that can be drawn from this
observation is that  (1) the organism must be a plant (2) the organism cannot be single celled
(3)  the organism must be an animal (4) not enough information is given to determine whether the organism is a plant
or an animal

54.  Why do scientists consider any hypothesis valuable?  (1) A hypothesis requires no further investigation. 
(2) A hypothesis may lead to further investigation even if it is disproved by the experiment.  (3) A hypothesis requires
 no further investigation if it is proved by the experiment.  (4) A hypothesis can be used to explain a conclusion even if
 it is disproved by the experiment.

55.  Using one or more complete sentences, state a likely cause for a decrease of an enzyme's 
       activity at very high or low pH values.

Constructed Response Section
Base your answer on the data table and your knowledge of biology. The data table shows water temperatures 
at various depths in an ocean.

1.   Using the information in the data table, construct a line graph on the grid with the following directions:
      Mark an appropriate scale on the axis labeled "Water Depth (m)."

2.   Correctly plot the points on the graph grid provided above.

3.  What is the dependent variable in the experiment summarized in the graph shown?
 

4. The graph at the right shows the relationship       between kidney function and arterial pressure      in humans.      State how a steady decrease in arterial pressure       will affect homeostasis in the human body.

5. How do guard cells of a leaf help to maintain homeostasis in a plant? [1]

6. Systems in the human body interact to maintain homeostasis. Four of these systems are listed below.

                                                  Body Systems
                                                    circulatory
                                                    digestive
                                                    respiratory
                                                    excretory

Select two of the systems listed. Identify each system selected and state its function in helping to maintain homeostasis in the body.

Explain how a malfunction of one of the four systems listed disrupts homeostasis and how that malfunction could be prevented or treated. In your answer be sure to:

• name the system and state one possible malfunction of that system
• explain how the malfunction disrupts homeostasis
• describe one way the malfunction could be prevented or treated

7. Many people who are in favor of alternative medicine claim that large doses of vitamin C introduced into a 
    vein speed up the healing of surgical wounds. Describe an experiment to test this hypothesis. Your answer 
    must include at least:

• the difference between the experimental group of subjects and the control group
• two conditions that must be kept constant in both groups 
• data that should be collected
• an example of experimental results that would support the hypothesis
 

8. Vaccinations play a major role in medicine today. Explain the role of vaccines in the prevention of disease. 
    Your answer must include at least:
• a description of the contents of a vaccine
• a description of how a vaccine protects the body from disease
• one specific reason certain vaccinations are required for students to attend public schools
 
 

Base your answers to questions 9 and 10 on the word equation shown below and on your  knowledge of biology.

9.     Name the process represented by the equation. 10.   Name the molecule represented by letter X.

11.  Just like complex organisms, cells are able to survive by coordinating various activities. Complex organisms 
       have a variety of systems, and cells have a variety of organelles that work together for survival.  Describe 
       the roles of two organelles. In your answer be sure to include:

• the names of two organelles and function of each
• an explanation of how these two organelles work together 
• the name of an organelle and the name of a system in the human body that have similar functions

12.  Immunization protects the human body from disease. The success of vaccinations can be seen in the fact that smallpox has been eliminated worldwide from the list of common infectious diseases. The only remaining smallpox viruses on Earth are thought to be those kept in certain research laboratories.

The United States is now committed to the goal of immunizing all children against common childhood diseases. However, many parents are choosing not to immunize their children against childhood diseases such as diphtheria, whooping cough, and polio.   For example, the mother of a newborn baby is concerned about having her child receive the DPT (diphtheria, whooping cough, and tetanus) vaccine. Since these diseases are caused by bacteria, she believes antibiotic therapy is a safe alternative to vaccination.

Discuss the use of antibiotics and vaccines in the treatment and prevention
of bacterial diseases. In your answer be sure to include:

• what is in a vaccine
• how a vaccine promotes immunity
• one advantage of the use of vaccinations to fight bacterial diseases

Connect here for answers to this practice midterm.

Please send comments or questions to Jim Buckley at jbuckley@ekcsk12.org