EOC Practice Test - DO NOT WRITE ON THIS!!
1. What is the best definition of a scientific theory?
a. An explanation of how and why a natural phenomenon behaves the way it does
b. A description of an invariable relationship that exists in nature
c. A speculation or guess about how nature works
d. An unproven fact
2. While doing an experiment, students burned 100 g of rice until only 5 g of inorganic material remained. Determine
the percent of inorganic material in this rice sample.
a. 0.05%
c. 20%
b. 5%
d. 90%
3. Which level of biological organization includes nonliving factors?
a. Organism
c. Community
b. Population
d. Ecosystem
4. Carbon-14 is a radioactive isotope used to determine the age of ancient objects composed of organic matter.
Carbon-12 and carbon-13 are other isotopes of carbon. The number of what subatomic particles varies among these
carbon isotopes?
a. Electrons
c. Photons
b. Neutrons
d. Protons
5. What is the maximum number of covalent bonds that can form between a single carbon atom and 1 or more
hydrogen atoms?
a. 1
c. 3
b. 2
d. 4
6. Which formula represents an inorganic molecule?
a. NH2CH2COOH
c. CO2
b. C12H22O11
d. CH3-CH(NH2)-COOH
7. As part of an experiment, a student adds 10 mL of 5% sodium hydroxide to 100 mL of a non-buffered, colorless
solution of sugar. What is the most likely result?
a. The concentration of hydroxide ions (OH-) will increase
c. The pH will not change
+
b. The concentration of hydroxide ions (H ) will increase
d. The pH will decrease
8. Which solution has the greatest concentration of hydrogen ions (H+)?
a. Urine (pH 6.0)
c. Tomato juice (pH 4.0)
b. Rainwater (pH 5.5)
d. Gastric juice (pH 2.0)
9. Which statement most accurately describes the induced fit model of enzyme function?
a. Substrate binding is not dependent upon the shape of the active site.
b. Competitive inhibitors block the substrate from the active site.
c. Substrate binding slightly changes the shape of the enzyme.
d. An enzyme creates a permanent bond with the substrate
10. During aerobic cellular respiration, in which of the following locations do ATP molecules form?
a. Cytosol only
b. Mitochondrial matrix only
c. Mitochondrial matrix and outer mitochondrial membrane only
d. Cytosol, mitochondrial matrix, and outer mitochondrial membrane
only
11. A science teacher performs an experiment to measure the CO2 uptake of the green algae Chlorella under light
conditions. He prepares a suspension of Chlorella and places it in a growth chamber near a lamp. A student disrupts the
experiment by turning off the tamp, creating dark conditions. Why is there a negative uptake of CO2 under dark
conditions?
a. CO2 production requires light .
c. Chlorella is actively photosynthesizing.
b. Cellular respiration is taking place. d. Glucose production in the dark requires less CO2.
12. A scientist studies the effects that temperature has on the growth of rice, weeds, and insects. Temperature, rice,
and insects make up which level of biological organization?
a. Population
c. Ecosystem
b. Community
d. Biome
13. A researcher counted the number of eggs a single fruit fly laid in 24 hrs for 5 days and recorded the findings in this
table.
What is the average number of eggs laid per day over the 5 days?
a. 10
c. 22
b. 16
d. 26
14. Omid is spending the semester in England where the road signs are in km. If he drives from his school into a town 6
mi away, how many km will he drive?
a. 3.73
c. 9.66
b. 4.00
d. 11.00
15. Many insects produce pheromones (chemical signals) to facilitate mating and reproduction. Scientists have
discovered that pheromones, if given at a certain time in an insect's life cycle, can confuse male insects and disrupt the
mating process. Crop growers want to use this knowledge to help control insect pests. Which step would be least likely
to change this scientific information into a usable technology?
a. Determining which pheromones most disrupt the mating of common insect pests
b. Determining when, during an insect pest's life cycle, the application of pheromones would most disrupt
mating
c. Developing a practical means of dispersing the pheromones
d. Developing stronger insecticides to kill insects not affected by the pheromones
16. The students used correct lab practice when handling samples of pond water. Which practice is NOT an example of
correct lab practice?
a. Wearing disposable gloves
c. Disinfecting the lab countertop before and after each lab
session
b. Discarding samples down the drain d. Washing hands before and after each lab session
17. A scientific theory is based on experimental results that satisfy which criterion?
a. They can be replicated by others.
b. Their significance is supported by experts.
c. They are absolute and cannot be challenged.
d. They are inconsistent with personal experience.
18. What is the goal of basic scientific research in biology?
a. Finding cures that will prolong human life through the study of disease
b. Providing a better understanding of the origin of life in the universe
c. Developing a more complete understanding of the interactions within and surrounding living organisms
d. Creating a comprehensive set of laws that allow us to predict how matter behaves and interacts
19. A microbiologist wants to determine whether a certain chemical affects the growth rate of bacteria. Which method
would be most efficient and reliable for tracking the bacteria population's growth rate each hr for 24 hrs?
a. Counting individual bacterial cells
b. Determining the mass of the tube containing the bacteria
c. Measuring the light absorbance of the populations in the tubes using a spectrophotometer
d. Calculating the size of the population using the average doubling time of the bacteria in the absence of the
chemical
20. If a researcher makes an experimental observation that is contrary to well-established scientific understanding,
what should the next step be?
a. Ignoring the results of the experiment if they support the hypothesis
b. Re-evaluating the procedure and replicating the experiment
c. Publishing the research in a well-known journal
d. Manipulating the data so it conforms to current understanding
21. What key factor distinguishes organic compounds from inorganic compounds?
a. Organic compounds contain carbon.
c. Organic compounds provide energy for cells.
b. Organic compounds contain hydrogen.
d. Organic compounds are the building blocks of cells.
22. Which functional group found in DNA is absent from monosaccharides, polysaccharides, fatty acids, and glycerol?
a. -COOH
c. -OH
b. -NH2
d. -PO4
23. How do enzymes speed up chemical reactions?
a. By reducing activation energy
c. By increasing activation energy
b. By reducing energy produced by the reaction
d. By increasing energy produced by the reaction
24. Pepsin is a protein-digesting enzyme in the human stomach. Antacids cause the pH of the stomach to increase and
protein digestion becomes less efficient. What occurs to reduce the efficiency of protein digestion?
a. Antacids break the covalent bonds within pepsin.
c. The active site of pepsin changes shape.
b. Pepsin dissolves antacids in the gastric juice.
d. The concentration of pepsin increases.
25. When the pH in a stomach decreases from 4 to 2, how does the hydrogen ion (H+) concentration change?
a. It increases by a factor of 2
c. It decreases by a factor of 2
b. It increases by a factor of 100
d. It decreases by a factor of 100
26. Red blood cells have a salt content of 0.9%. When a microbiologist places red blood cells in pure water, osmosis
occurs. What net movement of a substance occurs in this instance of osmosis?
a. Water molecules move out of the cells
b. Water molecules move into the cells
c. Salt ions move out of the cells
d. Salt ions move into the cells
27. The diagram shows a cell membrane composed of a phospholipid bilayer with a channel protein. Each x represents
the same type of molecule inside or outside the cell. Facilitated diffusion moves these molecules across the cell
membrane.
In what direction do these molecules move and through which structure?
a. Into the cell through the channel protein
c. Out of the cell through the channel protein
b. Into the cell through the phosphilipid bilayer
d. Out of the cell through the phospholipid bilayer
28. These diagrams represent different stages of animal cell division.
From start to finish, what is the correct order of the stages?
a. 2, 4, 3, 1
c. 3, 4, 2, 1
b. 2, 3, 4, 1
d. 3, 2, 4, 1
29. Megan examines a liver cell and observes an organelle with many smooth-sided channels. Which activity would
identify this organelle as the smooth endoplasmic reticulum?
a. Digestion of macromolecules and old organelles
b. Detoxification of poisonous molecules within the cell
c. Harvesting of energy from organic molecules to make ATP
d. Processing and packaging of cellular materials prior to export
30. Naomi adds cycloheximide to cells grown in a test tube. Within minutes, she identifies short incomplete segments
of proteins in the cells. On which organelle does cycloheximide act?
a. Endoplasmic reticulum
c. Nucleus
b. Golgi apparatus
d. Ribosome
31. The Krebs cycle produces what type of molecules?
a. NADH, CO2 and ATP
b. NADH, CO2, FADH2, and ATP
c. Pyruvate, CO2, NADH and ATP
d. Pyruvate, CO2, FADH2 and NADH
32. What is the purpose of meiosis?
a. To produce 2 cells, each with 1 complete set of chromosomes
b. To produce 2 cells, each with half the normal number of chromosomes
c. To produce 4 cells, each with 1 complete set of chromosomes
d. To produce 4 cells, each with half the normal number of chromosomes
33. Which process generates ethanol in the absence of oxygen?
a. Electron transport chain
c. Glycolysis
b. Fermentation
d. Krebs cycle
34. While investigating yeast respiration, a researcher detects ethanol in the yeast culture. Which molecule does the
yeast culture also contain?
a. Lactic acid and ATP
c. Carbon dioxide and ATP
b. Oxygen and lactic acid
d. Oxygen and carbon dioxide
35. During which phase of mitosis do spindle fibers separate sister chromatids?
a. Anaphase
c. Prophase
b. Metaphase
d. Telophase
36. By what process does a sodium ion exit a cell through the plasma membrane?
a. Active transport
c. Facilitated diffusion
b. Exocytosis
d. Osmosis
37. A scientist places a cell in a solution, and over time the cell gains mass and swells. What is the most likely
explanation for the cell's gain in mass?
a. The solution is hypertonic to the cell
c. The solution and the cell have equal concentrations of
solutes
b. The solution is hypotonic to the cell
d. The solution and the cell have equal concentrations of water
38. What combines with sugar and a phosphate group to form a nucleotide?
a. Amino acid
c. Glycerol
b. Deoxyribose
d. Nitrogenous base
39. In humans, pigmented skin is dominant to non-pigmented skin (albinism). What is the genotype of an individual
without albinism who had a parent with albinism?
a. Carrier
c. Homozygous dominant
b. Heterozygous
d. Homozygous recessive
40. Adrenoleukodystrophy (ALD) is a sex-linked recessive trait that affects the nervous system. In one family, the father,
mother, daughter and elder son do not have ALD, while the younger son has ALD. Who must be a carrier of the ALD
allele?
a. Father
c. Daughter
b. Mother
d. Elder son
41. Achondroplasia is a genetic disease in which the limbs of an individual are shorter than the average person. Males
and females must inherit 1 allele with this mutation to have the disease. What is the mode of inheritance of
achondroplasia?
a. Autosomal dominant
b. Autosomal recessive
c. Sex-linked dominant
d. Sex-linked recessive
42. DNA and RNA have many structural similarities. Which structure in DNA and RNA is similar?
a. Purine bases
c. Type of sugar
b. Pyrimidine bases
d. Attached proteins
43. This molecule is an example of which substance?
a. Amino acid
c. Fatty acid
b. Carbohydrate
d. Nucleotide
44. What occurs during metaphase I of meiosis?
a. Centromeres of replicated chromosomes line up along the cell's equator
b. Centromeres divide as sister chromatids move toward opposite poles of the cell
c. Homologous chromosome pairs line up along the cell's equator
d. Homologous chromosomes move toward opposite poles of the cell.
45. Two black guinea pigs bred and produced 3 black offspring and 2 albino offspring. Assuming no mutations, which
guinea pigs must be heterozygous?
a. All 3 black offspring
c. Both albino offspring
b. Exactly 2 of the black offspring
d. Both parents
46. Alkaptonuria is a genetic disorder of protein metabolism. The disorder is determined by 2 alleles at 1 locus.
What is the genotype for individual 1 in the diagram?
a. AA or Aa
c. Aa
b. AA
d. aa
47. A trisomy of chromosome 21 causes what condition?
a. Albinism
c. Down syndrome
b. Dwarfism
d. Color blindness
48. During what phase of meiosis does nondisjunction occur?
a. Metaphase I
c. Prophase II
b. Anaphase I
d. Metaphase II
49. Jeanine inherited 2 alleles for round eye shape and has round eye shape. Her brother inherited 1 allele for round
eye shape and 1 allele for almond eye shape and has almond eye shape. What type of trait is round eye shape?
a. Co-dominant
b. Dominant
c. Recessive
d. Sex-linked
50. In humans, red-green color blindness is a recessive, sex-linked trait. The chromosomes and alleles associated with
color blindness are represented in this chart.
Which child could NOT be born to these parents: a female (XBXb) and a male (XBY)?
a. Color-blind daughter
c. Daughter with normal color vision
b. Color-blind son
d. Son with normal color vision
51. Lazzaro Spallanzani and Louis Pasteur both performed experiments hoping to disprove spontaneous generation.
What conditions existed in Pasteur's experiment that did not exist in Spallanzani's?
a. Air could enter the flasks, but no microorganisms could enter.
b. No air could enter the flasks, but microorganisms could enter.
c. Neither air nor microorganisms could enter the flasks.
d. Both air and microorganisms could enter the flasks.
52. Who helped disprove the idea of spontaneous generation by demonstrating that maggots come from fly eggs and
NOT from meat?
a. Francisco Redi
c. Lazzaro Spallanzani
b. John Needham
d. Louis Pasteur
53. Stanley Miller and Harold Urey's experiment recreated Earth's hypothetical early atmosphere. What was their
conclusion?
a. Spontaneous generation could not occur.
b. Earth's early atmosphere contained oxygen gas.
c. Organic molecules could form from inorganic substances.
d. Many simple organisms could form from Earth's early atmosphere.
54. What process of natural selection favors the extreme phenotypes of a trait and eliminates intermediate
phenotypes?
a. Directional selection
c. Random selection
b. Disruptive selection
d. Stabilizing selection
55. This figure represents what type of tissue?
a. Adipose
c. Muscle
b. Epithelial
d. Nervous
56. What physiological system includes the hypothalamus, the thyroid gland, and the adrenal gland?
a. Endocrine
b. Nervous
c. Reproductive
d. Respiratory
57. Which figure represents blood cells?
58. The pancreas produces which hormones?
a. Insulin and glucagon
c. Estrogen and progesterone
b. Oxytocin and prolactin
d. Epinephrine and norepinephrine
59. Renaldo grew algae in the presence of a poison that stops the light-independent reactions of photosynthesis. As a
result, which molecules will the light-dependent reactions stop producing?
a. ADP and NADP+
c. ATP and NADP+
b. ADP and NADPH
d. ATP and NADPH
60. What is the correct sequence of events during photosynthesis?
a. Light absorption, electron transport chain, Calvin cycle, chemiosmosis
b. Chemiosmosis, light absorption, Calvin cycle, electron transport chain
c. Chemiosmosis, light absorption, electron transport chain, Calvin cycle
d. Light absorption, electron transport chain, chemiosmosis, Cavin cycle
61. All members of which of the following groups have a cell wall made up of chitin?
a. Fungi
c. Protists
b. Bacteria
d. Viruses
62. A Gram stain can be used to distinguish between which type(s) of organisms?
a. Different groups of bacteria c. Bacteria and protists
b. Different groups of protists d. Bacteria and viruses
63. Scientists discover a new invertebrate in the rainforests of Argentina. This small creature has an exoskeleton, three
body segments, six legs, compound eyes and jointed appendages. To what known animal would this new invertebrate
be most closely related?
a. Grasshopper (Insecta)
c. Millipede (Myriapoda)
b. Lobster (Crustacean)
d. Spider (Arachnida)
64. An entomologist identified a new species of beetle in a Southern American rain forest. The beetle has all the
features of the darkling beetle family Tenebrionidae and closely resembles other darkling beetles of the genus Tenebrio.
What should the entomologist do next?
a. Give the beetle new genus and family names
b. Give the beetle a new species name not used in the genus Tenebrio
c. Name the beetle after the species it is most similar to
d. Discard the beetle because it is not found in existing taxonomy
65. What is the path of deoxygenated blood at it enters a 4-chambered heart?
a. Pulmonary vein -> left atrium -> left ventricle -> aorta
b. Pulmonary vein -> right atrium -> left atrium -> aorta
c. Vena cava -> right atrium -> left atrium -> pulmonary artery
d. Vena cava -> right atrium -> right ventricle -> pulmonary artery