Many years ago, beavers were introduced to a region of California that they had not previously inhabited. Forty years later, the beaver population had grown so much that a cluster of aspen trees used by the beavers for food and building materials inside the national forest became endangered. The beavers were also interfering with the water systems.
In retrospect, how would biologists most likely evaluate the impact of the introduction of the beaver?
Answer : B
There is more vegetation present in areas with mild climates than in areas with harsh climates. Pollen analysis is one of the tools used to study past climates. The diagram at the left shows information about sediments of the same age, sampled from different parts of the world.
Which of the sediments most likely represents the area with the mildest climate?
Answer : D
A food chain is a way of showing food relationships among a group of organisms that share an environment. The illustration at the left represents a freshwater food chain.
What is most likely to happen if the supply of large fish in a pond is reduced by extensive fishing?
Answer : C
During a clear night, many stars are visible from Earth. During the day, the only visible star is the Sun. Why are other stars not visible during the day?
Answer : C
Which is the best conclusion about the nutritional value of hot dogs based on the information in the chart?
Answer : A
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Since carbon dioxide dissolves in water to form an acid, an acid-base indicator such as bromthymol blue is used to track the acid concentration during plant photosynthesis and respiration. Bromthymol blue turns yellow in an acid solution and remains blue in a basic solution. The color change is reversible. A student used the following procedure to track carbon dioxide.
In an experiment, a student placed a solution of bromthymol blue into each of two flasks, inserted a drinking straw in each flask, and blew through the straw until the solution turned fromblue to yellow. Carbon dioxide, a waste product in the students breath, caused the color change. The student then placed a small Elodea water plant in each flask and closed the flasks with rubber stoppers. Flask A was placed in bright sunlight, while flask B was placed in the dark for 24 hours, as shown in the figure below.
After 24 hours, the bromthymol blue in flask A had turned back to blue, while in flask B it was still yellow.
-- Exhibit
The experiment was designed to track what substance?
Answer : D
-- Exhibit --
Since carbon dioxide dissolves in water to form an acid, an acid-base indicator such as bromthymol blue is used to track the acid concentration during plant photosynthesis and respiration. Bromthymol blue turns yellow in an acid solution and remains blue in a basic solution. The color change is reversible. A student used the following procedure to track carbon dioxide.
In an experiment, a student placed a solution of bromthymol blue into each of two flasks, inserted a drinking straw in each flask, and blew through the straw until the solution turned from blue to yellow. Carbon dioxide, a waste product in the students breath, caused the color change. The student then placed a small Elodea water plant in each flask and closed the flasks with rubber stoppers. Flask A was placed in bright sunlight, while flask B was placed in the dark for 24 hours, as shown in the figure below.
After 24 hours, the bromthymol blue in flask A had turned back to blue, while in flask B it was still yellow.
-- Exhibit --
If living things use oxygen and release carbon dioxide during respiration, what is the most probable reason that the atmosphere does not become depleted of oxygen and become filled with carbon dioxide?
Answer : A
-- Exhibit --
Since carbon dioxide dissolves in water to form an acid, an acid-base indicator such as bromthymol blue is used to track the acid concentration during plant photosynthesis and respiration. Bromthymol blue turns yellow in an acid solution and remains blue in a basic solution. The color change is reversible. A student used the following procedure to track carbon dioxide.
In an experiment, a student placed a solution of bromthymol blue into each of two flasks, inserted a drinking straw in each flask, and blew through the straw until the solution turned from blue to yellow. Carbon dioxide, a waste product in the students breath, caused the color change. The student then placed a small Elodea water plant in each flask and closed the flasks with rubber stoppers. Flask A was placed in bright sunlight, while flask B was placed in the dark for 24 hours, as shown in the figure below.
After 24 hours, the bromthymol blue in flask A had turned back to blue, while in flask B it was still yellow.
-- Exhibit --
What relationship was the experiment designed to explore?
The relationship between light and:
Answer : E
Touch sensors of nerves adapt to some degree after they have been stimulated for a period of time. On the first touch, a very high impulse rate of nerve signals is sent to the brain. But the rate then slows until some sensors stop responding altogether.
Which of the following is an example of the nerve touch sensors slowing down?
Answer : A
The basic unit of structure and function of a living thing is a cell. A group of specialized cells of the same type works together to form a tissue. Tissues work together to form an organ. Organs work together to form an organ system. Complete systems work together to form a multicellular organism.
According to this organizational description, what is an eye?
Answer : C
In a suspension, two materials will mix together only temporarily. One material does not dissolve into the other, but stays suspended only until gravity pulls it down.
Which is an example of a suspension?
Answer : B
A major volcanic eruption put large amounts of dust into the upper atmosphere. For three years following the eruption, Earths weather was cooler than normal. Which of the following is NOT a testable hypothesis regarding the relationship between the eruption and the weather?
Answer : D
If a weight with a string attached is swung in a horizontal circular motion around in the air, the path of the weight will appear as shown in the figure at the left.
If the string breaks when the weight is at position A, the weight will fly away in a straight line tangent to the circular path.
In order for the weight to hit an object located at position X, the person should let go of the string when the weight is located at which position?
Answer : D
Sugar is produced in the sugar beets leaves through photosynthesis and then is transported to the root. The root of a sugar beet weighs from 1.5 to 3 pounds.
For what purpose is the root of the sugar beet adapted?
Answer : B
Atmospheric pressure decreases as you get higher in altitude. What is the primary reason helium balloons released in the air eventually burst?
Answer : A
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