Biology Honors Midterm Study Guide
Completion
Complete each sentence or statement.
1. ____________________ is the study of the interaction of organisms with their environment and with each
other.
2. To function properly, all living things must maintain a constant internal environment through the process of
____________________.
3. An educated guess, or a(n) ____________________, may be tested by experimentation.
4. Stating in advance the result that may be obtained from testing a hypothesis is called
____________________.
5. A unifying explanation for a broad range of observations is a ____________________.
6. A ____________________ experiment is one in which the condition suspected to cause the effect is
compared to the same situation without the suspected condition.
7. The base unit for length in the Système International d’Unités (International System of Units) is the
____________________.
8. A ____________________ electron microscope passes a beam of electrons over a specimen’s surface,
whereas a ____________________ electron microscope passes a beam of electrons through a thin slice of a
specimen.
9. Substances that are changed when they become involved in chemical reactions are called
____________________, while the new substances that are formed are called ____________________.
10. The energy needed to break existing chemical bonds during the initiation of a chemical reaction is called
____________________.
11. Chemical reactions in the body can be speeded up by adding a(n) ____________________, which lowers the
amount of activation energy required to start the reaction.
12. The loss of electrons from a molecule is called ____________________, while the gain of electrons by a
molecule is called ____________________.
13. A substance that dissolves in another is called a(n) ____________________.
14. ____________________ is the most common solvent in cells.
15. ____________________ and ____________________ ions form when water dissociates.
16. An acidic solution is one that has more ____________________ than ____________________ ions.
17. A solution with a pH of 3 has ____________________ times more hydronium ions than a solution with a pH
of 6.
18. Buffers are important because body fluids must be maintained within a relatively narrow range of
____________________.
19. Water is very effective at dissolving other polar substances because of its ____________________.
20. Breaking of ____________________ bonds is the first thing that happens when water is heated, which means
that it takes a great deal of thermal energy to raise the temperature of water.
21. Because carbon atoms have four electrons in their outermost energy level, they can form up to
____________________ covalent bonds with other atoms.
22. In the molecule that has the chemical formula C2H4, the carbon atoms are bonded together with a
____________________ bond.
23. In a condensation reaction, two molecules become linked together and a molecule of ____________________
is produced.
24. The formation of polymers from monomers occurs as a result of ____________________ reactions, and the
breakdown of polymers into monomers occurs as a result of ____________________ reactions.
25. Lipids are ____________________ molecules because they have no negative and positive poles.
26. A substrate attaches to the ____________________ of an enzyme.
27. In a triple bond, ____________________ pair(s) of electrons is (are) shared between two atoms.
28. ATP contains ____________________ phosphate groups.
29. The statement “Cells are produced only from existing cells” is part of the ____________________.
30. The ratio of surface area to ____________________ puts limitations on a cell’s size.
31. Eukaryotic cells are much larger and have more specialized functions than prokaryotic cells because they
contain ____________________, which carry out specialized activities.
32. A cell with a well-defined nucleus and cytoplasm surrounded by a plasma membrane is a(n)
____________________ cell.
33. A plasma membrane is said to be ____________________ permeable because it allows the passage of some
solutes and not others.
34. ____________________ molecules have “heads” and “tails” and are found in the plasma membrane.
35. Scientists have discovered that cells contain smaller specialized structures known as ____________________.
36. The spherical organelles that are the site of protein synthesis in a cell are the ____________________.
37. The meshlike network of protein fibers that supports the shape of the cell is called the
____________________.
38. The fluid portion of the cytoplasm is called the ____________________.
39. Photosynthesis takes place in the ____________________ of plant cells.
40. Both plant and animal cells have plasma membranes. In addition, plant cells are surrounded by a(n)
____________________.
41.
Refer to the illustration above. The diagram shows the ____________________ that makes up the framework
of the plasma membrane.
42. Matthias Schleiden worked with ____________________ cells, and Theodor Schwann worked with
____________________ cells.
43. Some plants produce a _________________________ between the plasma membrane and the primary cell
wall.
44. Stacks of thylakoids, called ____________________, are suspended in the stroma of chloroplasts.
45. A photosynthetic pigment that absorbs primarily red and blue wavelengths of light and appears green is called
____________________, while pigments that absorb other wavelengths and appear yellow and orange are
called ____________________.
46. Organisms that harvest energy from either sunlight or chemicals in order to make food molecules are called
____________________.
47. The main pigment associated with the two photosystems is ____________________.
48. The abundance of oxygen in Earth’s atmosphere is a result of millions of years of ____________________.
49. Chemiosmosis in the thylakoid membrane results in the synthesis of ____________________.
50. The second stage of photosynthesis, in which glucose is manufactured, is called the ____________________.
51. ____________________ plants have an enzyme that can fix CO2 into four-carbon compounds.
52. ____________________ is the study of how organisms interact with each other and with their environment.
53. An ecosystem consists of the living and ____________________ environment.
54. The physical area in which an organism lives is called its ____________________.
55. An ecological model is limited in its application because no model can account for every
____________________ in an environment.
56. Organisms that do not regulate their internal conditions are called ____________________, while those that
do are called ____________________.
57. The ____________________ of an organism includes its habitat, its feeding habits, other aspects of its
biology, and its interactions with other organisms and with the environment.
58. If a deer in a forest is classified as a herbivore, then the cougar that eats the deer is classified as a(n)
____________________.
59. Animals that eat only primary producers are classified as ____________________.
60. Bacteria that break down dead tissue are called ____________________.
61. When the interrelated food chains in an ecosystem are represented together, the model is called a(n)
____________________.
62. The primary productivity of an ecosystem is a measure of the amount of organic material that the
____________________ organisms in the ecosystem produce.
63. A one-way path of feeding relationships among organisms in an ecosystem is called a(n)
____________________.
64. In an ecosystem, ____________________ diminishes at each successive trophic level.
65. An energy pyramid shows the amount of energy contained in the bodies of organisms at each
____________________ level.
66. Every time energy is transferred in an ecosystem, some of the energy is lost as ____________________.
67. Cellular respiration and photosynthesis are the two processes that form the basis of the biogeochemical cycle
known as the ____________________ cycle.
68. When forests are cut down, both water and nutrient ____________________ are disrupted.
69. Water that seeps into the soil is called ____________________.
70. The conversion of nitrogen gas to nitrate by the action of bacteria is called ____________________.
71. The process of ____________________ occurs when anaerobic bacteria break down nitrates and release
nitrogen gas back into the atmosphere.
72. The biome that has coniferous trees as the dominant vegetation is the ____________________.
73. The thick, continually frozen soil layer found in the northern tundra is called ____________________.
74. ____________________ is a type of biome that is located in the middle latitudes and contains grasses, spiny
shrubs, and scattered clumps of trees.
75. The ____________________ is a cold and mostly treeless biome with a frozen soil layer.
76. Zebras, gazelles, and lions usually live in the biome called the ____________________.
77. The biome that makes up most of the central part of the continental United States is the
_________________________.
78. A dry grassland dominated by dense, spiny shrubs and scattered clumps of coniferous trees is called the
____________________.
79. Some plants have adapted for living in the desert by opening their ____________________ only at night.
80. Trees that lose their leaves every year are known as ____________________ trees.
81. _________________________ are characterized by lush vegetation, abundant rain, and year-round warm
temperatures.
82. The ____________________ zone is small in area but contains most of the ocean’s biodiversity.
83. Most of the ocean is the deep, open part known as the ____________________ zone.
84. A(n) ____________________ occurs where a major river flows into the ocean.
85. Streams in mountainous areas have____________________ gradients.
86. Marshes, swamps, and bogs are examples of _________________________.
Problem
87. Some scientists conducted an experiment in which they evaluated various measurements of human health in
people who drank at least one cup of coffee a day. They found no significant differences in these health
indicators between the subjects who drank only one cup of coffee a day and those who drank as many as 20
cups a day. They concluded that coffee has no adverse effects on human health. Write your answers to the
following in the spaces below.
a. What were the independent and dependent variables in this experiment?
b. Was this a controlled experiment? If so, what were the control and experimental groups?
c. Do you agree with the conclusion the scientists drew from their results? Why or why not?
88.
Refer to the illustration above. The graph depicts the relative energy levels of the products and reactants for
the following chemical reaction: A + B
C + D. Write your answers to the following in the spaces below.
a. Which substances, A, B, C, and/or D, are present at point 1 on the graph?
b. Which substances, A, B, C, and/or D, are present at point 3 on the graph?
c. Why is point 2 at a higher energy level than point 1?
d. Why is point 3 at a lower energy level than point 1?
e. Draw a dashed line on the graph indicating how the energy level of this reaction over time would be
different if the enzyme that catalyzes the reaction were not present.
89. All of the major components of the light reactions, including the pigment molecules clustered in photosystems
I and II, are located in the thylakoid membrane. What is the advantage of having these components confined
to the same membrane rather than dissolved in the stroma or the cytosol?
90.
Refer to the illustration above. Amy wants to test the hypothesis that the rate of photosynthesis is directly
related to the light level to which plants are exposed. She has chosen the aquatic plant Elodea as her study
organism. In her experimental design, she has four different tanks in which she will place Elodea plants. Each
Elodea plant will be placed inside an inverted test tube. She plans to estimate the relative rate of
photosynthesis by measuring the amount of oxygen produced by plants placed under different light levels.
She plans to compare the amount of oxygen gas that collects in the top of each of the test tubes.
Amy plans to place tank 3 next to a window in the classroom. She plans to place tank 2 ten feet away from the
window. She plans to place tank 1 twenty feet away from the window. She plans to place tank 4 in the
classroom’s refrigerator, because it is the only place she can find that is dark. Write your answers to the
following in the spaces below.
a. What is wrong with the design of Amy’s experiment?
b. What could Amy change in her experimental design to make it a better experiment?
Essay
91. Name five characteristics that are considered distinct properties of all living things. Write your answer in the
space below.
92. Toads that live in hot, dry regions bury themselves in the soil during the day. How might this be important to
the toad? Write your answer in the space below.
93. Define enzyme, and describe how an enzyme can function in speeding up a chemical reaction within a cell.
Write your answer in the space below.
94. How are the organs of a multicellular organism like the organelles of a single cell? Write your answer in the
space below.
95. Why do the cells of plant roots generally lack chloroplasts? Write your answer in the space below.
96. Define the terms autotroph and heterotroph. What types of organisms belong in each of these categories?
Write your answer in the space below.
97. Explain why the leaves of plants appear green to the human eye. Write your answer in the space below.
98. Summarize how the light reactions and the Calvin cycle work together to create the continuous cycle of
photosynthesis.
99. Explain how a change in the habitat of a species affects the entire ecosystem. What could ultimately result
from such a disruption? Write your answer in the space below.
100. Rabbits, coyotes, and clover plants are some of the organisms that occupy a particular ecosystem. Assign the
roles of primary producers, consumers, herbivores, and carnivores to these three groups of organisms and
explain your answer. Write your answer in the space below.