A scientist conducted an experiment to test the hypothesis that
maple seeds exposed to acid rain will take longer to germinate
than seeds exposed to normal rain, which has a pH of 5.6. The
scientist set up four groups, each containing 200 maple seeds.
The water used for each group had a different pH value: 5.6, 4.0,
3.0, and 2.0. All other conditions were kept the same. After ten
days, the number of seeds that had germinated in each group was
counted.
I.
-Identify the control group in this experiment.
II. -Identify the dependent and independent variable in this
experiment.
III. -State one example of experimental results that would indicate
that acid rain, which has a pH between 4.5 and 4.0, could be
responsible for a decrease in the number of young maple
trees in some forest regions.
A student states that exercise will affect the number of times a
person can squeeze a clothespin in a certain amount of time. An
experiment is carried out to test this hypothesis. One group of ten
students sits quietly before squeezing a clothespin as many times
as possible during a one-minute interval. A second group of ten
students does 25 jumping jacks before squeezing a clothespin as
many times a possible during a one-minute interval.
State one way the experiment could be improved in order to
increase the validity of the results.
You have been assigned to design an experiment to
determine the effects of light on the growth of tomato
plants. In your experimental design be sure to:
I. state one hypothesis to be tested
II. identify the independent variable in the experiment
III. identify the dependent variable in the experiment
IV. identify 2 constants
V. how will the control group be different from the
experimental group
VI. describe the type of data to be collected
VII. draw a data table with two columns and label them
appropriately
Plants respond to their environment in many different ways. Design an
experiment to test the effects of one environmental factor, chosen from the list
below, on plant Growth.
Acidity of precipitation
Temperature
Amount of water
In your answer, be sure to:
I.
state one hypothesis to be tested
II. identify the independent variable in the experiment
III. identify the dependent variable in the experiment
IV. identify 2 constants
V. how will the control group be different from the experimental group
VI. describe the type of data to be collected
VII. draw a data table with two columns and label them appropriately
Many plants can affect the growth of other plants near them. This
can occur when one plant produces a chemical that affects
another plant.
Design an experiment to determine if a solution containing
ground-up goldenrod plants has an effect on the growth of radish
seedlings. In your experimental design be sure to:
I. • state a hypothesis to be tested [1]
II. • describe how the experimental group will be treated
differently from the control group [1]
III. • explain why the number of seedlings used for the experiment
should be large [1]
IV. • identify the type of data that will be collected [1]
V. • describe experimental results that would support your
hypothesis
The photograph below shows a pill bug. Pill bugs are small
animals frequently found in wooded areas near decomposing
organic material.
Describe some parts of an experiment to determine the
preference of pill bugs for light or darkness. In your answer be
sure to:
I. state one hypothesis to be tested
II. identify the independent variable in the experiment
III. identify the dependent variable in the experiment
IV. identify 2 constants
V. how will the control group be different from the experimental
group
VI. describe the type of data to be collected
VII. draw a data table with two columns and label them
appropriately
VIII.state one example of experimental data that would support
your hypothesis
A student conducted an experiment to determine if listening to
different types of music would affect pulse rate. She thought that
pulse rate would change with different types of music. Each
person participating in her experiment listened to seven different
selections of music for 30 seconds each. The pulse rates were
taken after each 30-second interval of music. Based on her
experiment, the student concluded that a person’s pulse rate
changed when listening to different types of music.
The component missing from this experiment is a
(1) prediction
(2) hypothesis
(3) control group
(4) research plan
Students in a class recorded their resting pulse rates and their pulse rates immediately after
strenuous activity. The data obtained are shown in the histograms below.
I An appropriate label for the y-axis in each histogram would be
(1) Number of Students
(2) Average Number of Heartbeats
(3) Time (min)
(4) Amount of Exercise
II. According to the data, compared to the average resting pulse rate, the average pulse
rate immediately after strenuous activity generally
(1) decreased
(2) increased
(3) remained the same
(4) decreased and leveled off
III. State one biological explanation for the fact that not all students had the same resting
pulse rate.
Base your answers to questions 44
through 47 on the data table below and
on your knowledge of biology.
The data table shows the number of fish
species found at various ocean depths.
Directions (44–45): Using the information
in the data table, construct a line graph
on the grid, following the
directions below.
44 Mark an appropriate scale, without
any breaks, on each labeled axis. [1]
45 Plot the data from the data table.
Surround each point with a small circle
and connect the points. [1]
46 State the general relationship between
water depth and the number of fish
species found. [1]
47 The approximate number of fish
species that can be found at 120 meters
is
(1) 5
(3) 18
(2) 13 (4) 31
A biology class conducted an experiment to determine the rate of respiration of yeast in
bread dough at various temperatures. Bread dough will rise due to the production of carbon
dioxide by the yeast present in the dough. An equal amount of dough was placed in the
bottom of each of five graduated cylinders. Each cylinder was then placed in a different
water bath to maintain a particular temperature. A diagram of the setup is shown below.
The amount of expansion of the dough in each cylinder was measured after 15 minutes.
The results are shown in the data table below.
Using the information in the data table, construct a line graph on the grid, following the directions below.
Mark an appropriate scale, without any breaks, on the axis labeled “Temperature of Water Bath (°C).” [1]
Plot the data from the data table. Surround each point with a small circle and connect the points. [1]
At which temperature did yeast cells produce the least amount of gas in 15 minutes? [1]
_______________________°C
Identify the independent variable in this investigation. [1]
_______________________________________________________________________________________
Euglena are single-celled organisms that live in ponds. All euglena have chloroplasts and can make their own
food. They can also take in food from the environment. The diagram below represents a euglena. An experiment
was set up to determine the effect of nitrates, a pollutant, on the number of chloroplasts present in euglena. Five
tanks were set up, each with euglena and a different concentration of nitrate solution: 0%, 0.5%, 1.0%, 1.5%, and
2.0%. The tanks were placed in a sunny location where each tank received the same amount of light.
31 Which statement is a possible hypothesis for this experiment that could be supported by the results of this
experiment?
(1) If the average number of chloroplasts in euglena decreases, will less nitrate be needed in each tank?
(2) If the nitrate concentration is increased, then the euglena will have a lower average number of chloroplasts.
(3) If the number of euglena in a tank increases, will more nitrates be produced?
(4) If the nitrate concentration is decreased, then more light will reduce the average number of chloroplasts in
euglena.
32 Which statement correctly identifies a variable in this experiment?
(1) The independent variable is the concentration of nitrate solution used.
(2) The dependent variable is the number of euglena placed in the tanks.
(3) The independent variable is the amount of sunlight.
(4) The dependent variable is the number of tanks used.
33 Euglena can be classified as both
(1) an autotroph and a parasite (3) a producer and a parasite
(2) a decomposer and a heterotroph (4) an autotroph and a heterotroph
Which individual most likely has diabetes?
(1) A (3) both A and B
(2) B (4) neither A nor B
48 Identify one hormone associated with
the maintenance of blood glucose levels.
[1]
__________________________________
_________
Key
= Individual A
= Individual B
Blood Glucose (mg/100 mL)
Time (hr)
table below and on your
knowledge of biology.
Diabetes is a disease characterized by
consistently high blood glucose levels (at
or above
126 mg/100 mL) as a result of hormone
deficiency. For a study of diabetes, blood
glucose
levels from individual A and individual B
were recorded each hour over a 5-hour
period
following a meal. The results are shown in
the data table below.
Blood Glucose Levels
(mg/100 mL)
Directions (44 – 46): Using the information
in the data table, construct a line graph on
the grid on the next
page, following the directions below.
44 Mark an appropriate scale, without any
breaks, on each labeled axis. [1]
45 Plot the data for individual A on the grid,
surround each point with a small circle, and
connect the points. [1]
46 Plot the data for individual B on the grid,
DNA samples can be separated according
to size using the technique of
(1) chromatography (3) replication
(2) electrophoresis (4) dissection
The diagram below represents the results of a laboratory
procedure.
This procedure is used to
(1)separate molecules in a liquid mixture
(2)detect glucose in a solution
(3)determine the rate of photosynthesis in plants
(4)examine the gene sequences of organisms
A student performed a gel electrophoresis
experiment. The results are represented in
the diagram below.
Compared to the fragments at the top of the
gel, the fragments at the lower end are
(1) larger, and move slower
(2) smaller, and move faster
(3) larger, and move faster
(4) smaller, and move slower
Reasons for conducting peer review include
all of the following except
(1) analyzing the experimental design
(2) pointing out possible bias
(3) identifying an illogical conclusion
(4) changing data to support the hypothesis
The drawings below were made during a
laboratory exercise in which a microscope
was
used to view slides of preserved protozoa.
The microscope had a 10× eyepiece and
two
different objectives.
81 Which statement about the size of the
organisms is correct?
(1) Organism A is larger than organism B.
(2) Organism B is larger than organism A.
(3) Organisms A and B are both the same
size.
(4) The relative size of the organisms
cannot be determined from the information
given.
New varieties of organisms have resulted
from human activities. These organisms
have
often led to problems in modern society.
Two of these new varieties are listed
below.
Antibiotic-resistant bacteria
Pesticide-resistant insects
56–60 Select one of these varieties and
discuss a problem associated with the
development of this new variety
of organism. In your answer, be sure to:
• identify the variety you selected
• identify one biological process by which a
population of this variety may develop
resistance [1]
• describe how this process is involved in
the production of a population of resistant
organisms [1]
• identify one problem caused by this
resistance [1]
• state one solution to this problem [1]
• identify one possible negative effect of
this solution [1]
Variety:
The diagram below represents the
measurement of a biological specimen.
What is the approximate length of the
specimen in millimeters?
(1) 25 mm (3) 35 mm
(2) 30 mm (4) 40 mm
The diagram below shows a student heating some test tubes with chemicals in them
during a laboratory
activity.
Explain why putting stoppers in the test tubes could be dangerous. [1]
______________________________________________________________________
_________________
______________________________________________________________________
_________________
The materials represented in the diagram
below were used in a laboratory activity.
These materials were used to carry out the
technique known as
(1) DNA staining (3) paper chromatography
(2) genetic engineering (4) glucose testing
A coverslip should be slowly lowered from
a 45° angle onto a slide in order to
(1) prevent the slide from being scratched
(2) stop the loss of water from under the
coverslip
(3) ensure that the specimen being viewed
will stay alive
(4) reduce the formation of air bubbles
An experiment was designed to test whether students could
squeeze a clothespin more times in 1 minute after resting
or after exercising. What would be a hypothesis for the
experiment?
(1) Do students squeeze clothespins more often in 1
minute after exercising?
(2) Can most students squeeze a clothespin more times
after they rest?
(3) Ten students who exercise before squeezing a
clothespin squeezed it more times in 1 minute than ten
students who rested first.
(4) Students who rest before squeezing a clothespin will
squeeze it fewer times in 1 minute than students who
exercise beforehand.
An experiment was designed to test
whether students could squeeze a
clothespin more
times in one minute after resting or after
exercise.
Note: The answers to questions 81 and
82 should be recorded on your separate
answer sheet.
81 The dependent variable for this
experiment is the
(1) time the student was squeezing the
clothespin
(2) number of times the student was able
to squeeze the clothespin
(3) strength of the student
(4) length of the clothespin
82 The experimental results could be made
more valid by
(1) increasing the number of students (3)
using safety precautions
(2) using a plastic clothespin (4) making a
bar graph of the data
A chemical known as fertex affects external fertilization of sea urchin eggs. An
experiment was set up using three tanks to investigate the effect of fertex. Each
tank had a different concentration of fertex: 1%, 2%, and 3%. Ten sea urchin eggs
and 2 mL of sea urchin sperm were added to each of the three tanks. A fourth tank
was set up as a control.
State one way the contents of the control tank would differ from the contents of the
three experimental tanks.
Identify two factors that must be kept the same in all four tanks.
Factor 1:
Factor 2:
State one way to improve the validity of the experimental results.
Identify the independent variable in the experiment.
State one example of the type of data that should be collected during the
experiment.
An experiment was carried out to determine whether drinking
caffeinated soda increases pulse rate. The pulse rates of two
groups of people at rest were measured. Group A was then given
caffeinated soda and group B was given caffeine-free soda.
One hour after drinking the soda, the pulse rates were measured.
The participants in the experiment were all the same age, and
they were all given the same amount of soda.
The dependent variable in this experiment is the
(1) type of soda given to each group
(2) amount of soda given to each group
(3) pulse rate of each group
(4) age of participants in each group
Blown Away
Head Lice Meet Hair Dryer of Death
Head lice are becoming indestructible. A study found that as many as 80 percent of the
bugs are [resistant] to insecticides in over-the-counter shampoos, and resistance will
only increase. Evolutionary biologist Dale Clayton may have a new line of attack.
Clayton, who usually studies lice on bird feathers, stumbled onto his solution after a
major research setback. When he moved his laboratory from England to the University
of Utah a decade ago, his entire louse collection perished in the dry desert air. Soon
after, his 8-year-old came home from school with head lice. He wondered if human head
lice could also be killed by drying them out. “It was sort of a forehead slapper,” Clayton
says. After conventional hair dryers failed, Clayton came up with the LouseBuster, a 10pound device resembling a vacuum cleaner that desiccates [dries out] the bugs with a
jet of 140-degree air [140°F]. “It’s a pretty brutal assault,” he says. Tests show the
invention is both safe and effective, eradicating 80 percent of live lice and 98 percent of
eggs, leaving survivors unable to breed. And, Clayton says, “it will be awfully hard for
lice to develop resistance.”
Source: Emily Saarman, “Blown Away—Head Lice Meet Hair Dryer of Death,”
Discover Magazine, February 2007
I. State how Clayton first learned that desiccating lice kills them. [1]
II. state the hypothesis to be tested in the experiment [1]
III. state one way the control group will be treated differently from the experimental
group [1]
IV. state one result of the experiment that would support the hypothesis [1]
Daphnia (water fleas) are sensitive to many changes in pond
ecosystems. For this reason they are often used in bioassays,
tests in which organisms are exposed to various levels of a
chemical to determine what levels are safe. The results of these
tests determine whether or not the chemical being tested will
affect other pond organisms.
An experiment was designed to determine the toxicity of different
salt solutions on cultures of daphnia. Five fish tanks were each
filled with the same amount of water containing different
concentrations of salt. Ten daphnia were placed into each tank.
After
48 hours, the number of daphnia that had survived and the
number of daphnia that had died in each tank were recorded and
the percent mortality was calculated. The results of the
experiment are shown in the data table below.
Using the information in the data table, construct a line graph on
the grid on the next
page, following the directions below.
I. Label the x-axis. Be sure to include units.
II. Mark an appropriate scale, without any breaks, on each axis.
III. Plot the data for mortality on the grid. Surround each point
with a small circle and connect the points.
IV. Which salt concentration was most toxic to the daphnia in this
experiment?
(1) 1.25 g/L (3) 5.0 g/L
(2) 2.5 g/L (4) 10.0 g/L
V. Which salt concentration is most likely closest to the
concentration of salt found in the natural environment of this
species of daphnia? Support your answer.
Salt concentration:_______________________
Base your answers to questions 48 and 49 on the graph below and on your
knowledge of biology. The graph shows the number of species that became extinct
from 1800 to 2000. It also shows estimates of the number of species that will
become extinct between 2000 and 2020.
The number of species that became extinct between the years 1950 and 2000 is
approximately
(1) 5,000 (3) 22,000
(2) 12,000 (4) 37,000
Five students design an experiment to answer the question: “How is heart rate affected
by running?” Two chairs were set up at different ends of a large room. The pulse rate of
each student was taken at rest just before running. Each of the five students ran between
the chairs a different number of times. Their pulse rates were taken after running and
the results are shown in the table below.
If a control group is not included in an experiment, it would be difficult to
(1) formulate a hypothesis for the experiment (3) record data in a data table
(2) make observations about the experimental group (4) draw a valid conclusion
The bar graph below shows the height of a
plant at the end of each week of a fiveweek growth period.
Which statement represents a valid conclusion based on the information in the graph?
(1) The plant was given water during the first three weeks, only.
(2) The plant will grow faster during the sixth week than it did during the fifth week.
(3) The plant grew fastest during the first three weeks, and then it grew slower.
(4) The plant grew slowest during the first three weeks, and then it grew faster.
When using a compound light microscope,
the
most common reason for staining a
specimen
being observed is to
(1) keep the organism from moving around
(2) make the view more colorful
(3) determine the effects of chemicals on
the
organism
(4) reveal details that are otherwise not
easily seen
Thrips are insects that feed on the pollen and flowers of certain plants. The size of a
thrip populationdepends on the number of flowers available. Which graph best
represents changes in a population of thrips if winter was longer than usual and the
summer was too cool and dry for many flowers to bloom?