Biology Review Questions – Midterm Key
Biology Chapter 1 - What is Science?
1. The basic unit of length in the metric system is the meter.
2. A student sees a bee on a flower. The student wonders how the bee finds flowers. This student is displaying
the scientific attitude of curiosity.
3. Based on your observations, you suggest that the presence of water could accelerate the growth of bread
mold. This is a hypothesis.
4. A skeptical attitude in science means a new idea will only be accepted if it is backed by evidence.
5. Information gathered from observing a plant grow 3 cm over a two-week period is called data.
6. Which of the characteristics of living things best explains why some North American birds fly south for the
winter? Living things respond to their environment.
7. Be able to convert meters to kilometers and kilometers to meters.
8. A scientist discovers an important breakthrough in cancer treatment. The scientist thinks the information
could save thousands of lives and immediately announces the results on national television, skipping peer
review. How might other scientists react to this news? They will be skeptical because the report was not
peer-reviewed.
9. Know the goals of science. One goal of science is to provide natural explanations for events in the natural
world. Science also aims to use those explanations to understand patterns in nature and to make useful
predictions about natural events.
10. Know the characteristics of all living things. Living things are made up of basic units called cells, are based
on a universal genetic code, obtain and use materials and energy, grow and develop, reproduce, respond to
their environment, maintain a stable internal environment, and change over time.
11. Science is best described as a way of knowing.
12. Know the ways that science influences society. Science provides answers to some of society’s practical problems,
science advances technology that is useful to society, and science increases society’s understanding of how
people affect the environment.
13. A personal preference or point of view is a bias.
14. Know the big ideas of biology. Cellular basis of life, information and heredity, matter and energy, growth
development and reproduction, homeostasis, evolution, structure and function, unity and diversity of life,
interdependence in nature, and science as a way of knowing.
15. Know the fields of biology. Biotechnology, building the tree of life(diversity), ecology and evolution of
infectious diseases, genomics and molecular biology,
16. The statement “The insect is 3 centimeters long” is a(n) observation.
17. Be able to recognize questions that can and cannot be answered by science. Questions that cannot be answered
by science are those that cannot be tested, for example, questions that deal with relative values and morals.
18. A well-tested explanation that explains a lot of observations is a theory.
19. The work of scientists usually begins with careful observations.
20. The standard or English system of measurement uses units such as yards, miles, quarts, and gallons. The
metric system uses units such as meters, kilometers, milliliters, and liters. Why is the metric system easier
to use than the English system? The metric system is based on multiples of ten.
21. Using a universal system of measurement is MOST important during which part of scientific
methodology? Collecting data.
22. Cells in multicellular organisms have many different sizes and shapes. These differences in cells is called
cell specialization. Cell specialization allows cells to perform different functions.
23. What does a reviewer do during peer-review? Check for mistakes and bias.
24. To be useful in science, a hypothesis must be testable.
25. A scientific hypothesis can be tested by experiments or observations.
26. During a controlled experiment, a scientist isolates and tests a single variable.
27. A scientist working in which area of biology is MOST likely to study DNA? Information & heredity
28. The information gathered in an experiment is called data.
29. In a controlled experiment, the group that is exposed to the same conditions as the experimental group
except for the variable that is deliberately changed is the control group.
30. In a controlled experiment, the variable that is observed and that changes in response the variable that is
deliberately changed is called the dependent variable.
31. A logical interpretation based on what scientists already know is a(n) inference.
32. The type of reproduction in which cells from two parents unite to form the first cell of a new organism is
sexual reproduction.
33. In a controlled experiment, the variable that is deliberately changed is the independent variable.
34. The combination of chemical reactions through which an organism builds up or breaks down materials as
it carries out its life processes is called metabolism.
35. An organized way of gathering and analyzing evidence about the natural world is called science.
36. The part of the Earth in which life exists, including land, water, and air or atmosphere is called the
biosphere.
37. The type of reproduction in which a single organism produces offspring identical to itself is called
asexual reproduction.
38. A signal to which an organism responds is called a(n) stimulus.
39. Observation is the act of using your senses to notice and describe events or processes in
a careful, orderly way.
40. The study of life is called biology.
41. Be able to differentiate between a theory and a hypothesis.
42. Be able to describe the location and purpose of each of the following pieces of safety equipment found in
our classroom: fire extinguisher, fire blanket, eyewash, and safety shower.
Biology Chapter 2 - The Chemistry of Life
1. The pH scale is a measurement system that indicates the concentration of hydrogen ions in solution.
2. When an atom has gained or lost electrons, it is called a(an) ions.
3. A five-carbon sugar, a phosphate group, and a nitrogen base are all parts of a nucleic acid.
4. The elements or compounds that come out of a chemical reaction are products.
5. The substance formed when covalent bonds unite atoms is called a(an) molecule.
6. A water molecule is polar because there is an uneven distribution of electrons between the oxygen
and the hydrogen atoms.
7. An element or compound that enters into a chemical reaction is called a(an) reactant.
8. A chemical bond formed by the transfer of electrons is a(an) covalent bond.
9. The energy need to start a chemical reaction is called the activation energy.
10. Solutions that have more OH– than H+ ions are bases.
11. Solutions that have more H+ than OH– ions are acids.
12. Carbon-12 is the most common isotope of carbon. It has 6 protons, 6 neutrons, and 6 electrons. Of its 6 electrons,
4 are valence electrons. How many covalent bonds can a carbon atom form? 4
13. A covalent bond is formed as the result of sharing electrons.
14. Be able to answer questions about enzymes, substrates, active sites, and how enzymes work.
15. What is the process that changes one set of chemicals into another set of chemicals? Chemical reaction
16. Why is carbon so special compared to other elements? Carbon atoms can bind to one another and form a lot of
different structures.
17. Be able to differentiate between diagrams that show reactions that absorb energy and reactions that release
energy.
18. Enzymes affect the reactions in living cells by changing the speed of the reaction.
19. What are found in the space surrounding the nucleus of an atom? electrons
20. What is the monomer of a polysaccharide? Monosaccharide or simple sugar
What is the monomer of a protein? Amino acid
What is the monomer of a nucleic acid? Nucleotide
21. Isotopes are atoms of the same element with the same number of protons and a different number of neutrons.
22. Chemical reactions that release energy often occur spontaneously.
23. The three particles that make up atoms are protons, neutrons, and electrons.
24. If the pH of stomach acid and of ammonia were measured, the pH of stomach acid would be below 7, but the pH
of ammonia would be above 7.
25. Identify the reactant(s) and product(s) in the chemical reaction, CO2 + H2O ® H2CO3. Reactants: carbon dioxide
+ water. Products: carbonic acid
26. Which property of water causes the curved surface in a graduated cylinder (see the figure in your test)? adhesion
27. In chemical reactions, atoms are rearranged.
28. A solution is a mixture in which the substances are evenly spread out.
29. You should know that catalysts speed up the rate of chemical reactions, lower the activation energy for chemical
reactions, and are not used up during a chemical reaction.
30. Name the substance formed by the chemical joining of two or more elements in definite amounts. compound
31. Water molecules are polar, with the oxygen side being slightly negative and the hydrogen side being slightly
positive.
32. Acidic substances have a pH value below 7, neutral substances have a pH value of 7, and basic substances have a
pH value greater than 7. The more acidic a substance, the closer its pH value is to 0, the more basic a substance,
the closer its pH value is to 14.
33. Why is the melting of ice not a chemical reaction? Whether frozen or liquid, it is still water.
34. Why are atoms considered neutral? They have an equal number of protons and electrons
35. What is the difference between a saturated fatty acid and an unsaturated fatty acid? Saturated fatty acids have
only single carbon-carbon bonds. Unsaturated fatty acids have at least one carbon-carbon double bond.
36. List the 6 major elements of life. Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur
37. Name the functions for each of the following macromolecules: carbohydrates, lipids, proteins, and nucleic acids.
Carbohydrates: main source of energy for most organisms, Lipids: stored energy and heat insulation,
Proteins: control of reaction rate, regulation of cell processes, formation of important cellular structures,
transportation of substances into or out of cells, and disease fighting, Nucleic acids: storage and transmission of
genetic information.
Biology Chapter 3 The Biosphere
1. The total amount of living tissue within a given trophic level is called the biomass.
2. The total amount of living tissue at each trophic level in an ecosystem can be shown in a(n) biomass pyramid.
3. Why can’t the producers in some ecosystems make an unlimited supply of organic material? One or more nutrients
are in short supply
4. Primary producers are organisms that use energy taken in from the environment to convert inorganic molecules
into complex organic molecules.
5. Only 10 percent of the energy stored in an organism can be passed on to the next trophic level. Of the remaining
energy, some is used for the organism’s life processes, and the rest is elimated as heat.
6. What term describes a group of different species that live together in a defined area? community
7. In what way are herbivores and carnivores alike? They both obtain energy by consuming other organisms.
8. Corn planted in a field that has been previously planted with legumes and then plowed under is likely to be more
productive because bacteria living on the roots of legumes fix nitrogen in the soil.
9. A model of the complex feeding interactions among organisms in a community from producers to decomposers is
called a food web.
10. What animals eat both producers and consumers? herbivores
11. Be able to differentiate between biotic and abiotic factors.
12. Be able to name and describe the processes by which carbon cycles through the biosphere. Processes that return
carbon to the atmosphere: consumers by respiration, burning of forests and fossil fuels, Processes that remove
carbon from the atmosphere: producers by photosynthesis, decomposition of animals and plants into rocks.
13. A group of individuals that belong to a single species and that live together in a defined area is known as a(n)
population.
14. Which biogeochemical cycle does NOT include a major path in which the substance cycles through the
atmosphere? Phosphorus cycle
15. Be able to interpret a water cycle diagram and identify what is happening at each step in the diagram. Water
cycles into the atmosphere by evaporation from bodies of water and transpiration from plants. Water droplets
in the atmosphere condense into clouds. Water cycles back to the Earth by precipitation, water on the Earth
exists as runoff, gets into ground water, or runs into bodies of water such as lakes and streams, and eventually
back into the ocean. In bodies of water, evaporation starts again.
16. Nitrogen fixation is carried out primarily by bacteria.
17. A bird stalks, kills, and then eats an insect. Based on its behavior, which pair of ecological terms describes
the bird? Carnivore and consumer
18. Animals get the most of the nitrogen they need by consuming plants or other animals.
19. Which ecological inquiry method is an ecologist using when he or she sets up a greenhouse and measures the
effects of different levels of carbon dioxide on an endangered plant species? Experimenting.
20. All of life on Earth exists in the biosphere.
21. Be able to identify biotic factors that affect the size of a population in a specific ecosystem? Answers vary, should
have to do with some lifeform.
22. Which is a source of energy for Earth’s living things? Sunlight and chemical energy
23. What are the three kinds of ecological pyramids? Biomass, energy, and numbers
24. The repeated movement of water between Earth’s surface and the atmosphere is called the water cycle.
25. What is the term for each step in the transfer of energy and matter within a food web? Trophic level
26. The nonliving components of an ecosystem are called abiotic, while the living parts are called biotic.
27. Be able to interpret a food web to determine a food chain within the food web, the role of each organism on
the food web (producer, herbivore, carnivore, omnivore, etc.)
28. What is at the base of all ecological pyramids? Producers.
29. Animals that get energy by eating the carcasses of other animals that have been killed by predators or have died of