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Based on the diagram,
at which point is the least amount of force needed to move the weighted box?
Which household compound is hazardous when combined with sodium hypochlorite, which is found in bleach?
Students in a biology class were asked to construct hypotheses about the relationship between air temperature and the number of times crickets chirp per minute. They listened to a tape of crickets chirping at six different temperatures. The students counted the number of chirps per minute and recorded their results, which are shown in the table below.
Which statement best describes the relationship between the number of chirps and the air temperature?
Density is the relationship of the mass of an object to its volume. A formula that describes density isdensity = mass/volumewhere mass is the quantity of matter present and volume measures how much space the matter occupies.
Suppose that a tanker truck overturns, causing hazardous vapors to leak from the tank. As the vapors leak out, they appear to fall to the ground and then travel along the ground.
Which conclusion about density may be correctly drawn from this information?
Vertebrates, animals with backbones, are divided into the following five major groups: fish, reptiles, amphibians, birds, and mammals. Some characteristics of these groups are given in the table below.
Which statement is true if an animal lives in water, does not lay eggs, and is warm-blooded?
Exhibit:
Some recipes suggest that certain foods, such as sauces and frostings, be prepared in a double boiler, such as the one shown at the left.
Which statement best describes the advantage of using a double boiler?
Making bread involves a chemical reaction. A chemical reaction involves starting materials (the reactants) and the substances produced (the products).
Which material is a product of this chemical reaction?
The amount of carbon dioxide in the atmosphere is increasing, therefore contributing to the phenomenon called the greenhouse effect. The end result is an increase in average temperatures worldwide.
A decrease in global warming could result if we reduced the consumption of materials that give off carbon dioxide when burned.
To reduce global warming, what should be used LESS?
In the 1900s, the rate of extinction of animal species increased dramatically.
Which factor is most likely responsible?
A family wants to plant a garden, but the soil around the house is mainly clay. Clay soil easily becomes saturated with water, cutting off the air supply needed by plants. Adding sand and peat moss can help plants grow in clay soil.
Which is the procedure for preparing the clay soil for planting?
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?
Pressure is explained as the force (a push or a pull) applied on a surface, divided by the total area over which the force is applied. For example, more pressure is exerted under Abby’s heel wearing spiked heel shoes than under Abby’s heel wearing flat heeled shoes.
In figure A, the man is walking in snow with snowshoes and does not sink into the deep snow. In figure B, the man has no snowshoes on and immediately sinks into the deep snow.
What would cause the man in figure A to sink less deeply into the snow than the man in figure B?
Simple machines reduce the amount of force needed to do work such as lifting an object. The simple machine shown below is a lever. A downward force on one end of a lever moves the other end up. A playground seesaw or a crowbar are common examples of levers.
The amount of force needed to raise the box sitting on the lever depends on where the force is applied. The more distance between the weight and the force, the smaller the force that is needed.
In the diagram on the left, where would the LEAST amount of force be needed to move the weighted box?
For years, DDT was used for mosquito control in the marshlands near Long Island, New York. Authorities claimed DDT was safe because the poison would be diluted by the seawater. However, tests later revealed that tissues of fish-eating birds in the area contained DDT levels 500,000 times higher than that of the surrounding seawater.
Which statement best explains why the authorities were incorrect in their assessment of the environmental impact of the use of DDT?
Exhibit:
Based on this article, which statement is true for any defective gene a person carries?
Which of the following represents the approximate combined use (in quads) of natural gas and oil in 1997?
Light travels so fast that one can see an event at about the same time that it happens, such as turning on the light. When one sees lightning, it can be assumed that it happened at the same instant it was seen. Sound, on the other hand, travels more slowly. The sound of thunder takes 5 seconds to travel about 1 mile.
Based on the data,
which conclusion is correct?
The sugars and starches in the human diet are broken down into glucose in the digestive system. This glucose passes from the small intestine into the blood. Human blood glucose levels are regulated by two hormones produced by the Islets of Langerhans in the human pancreas. The hormones are insulin, which lowers the level of blood glucose, and glucagon, which raises it.
Which statement best describes what happens after one eats a meal high in sugar and starches?
Based on the information and graph, which statement provides the best conclusion?
Soil is formed when the rock at Earth’s surface weathers. Normally, soil develops into three layers, called horizons. The illustration below shows the A, B, and C horizons of a typical soil profile.
Based on the diagram, if the surface vegetation were removed, which would be the likely effect on the soil?
An electromagnet is a magnet that can be turned on and off. It consists of a central metal core, such as iron, and many wrappings of wire around the metal core. An electrical current sent through the wire wrappings causes the formation of a magnetic field. There are several ways to increase the strength of an electromagnet: increasing the number of wrappings, increasing the current of electricity, making the wrappings closer together, or increasing the diameter of the core.
Five electromagnets are shown above. The electrical power source for each electromagnet is an ordinary flashlight battery.
Which electromagnet will produce the strongest magnetic field?
The death rate from heart disease fell more than 8 percent in just one year during the 1980s. Advances in public awareness of heart disease and in treatments for it are thought to be partially responsible for the decline. New heart drugs, a technique called angioplasty for clearing the arteries, and surgical advances have also assisted in reducing heart disease fatalities, as has increased interest in a healthy lifestyle and diet.
Which of the following was a contributing factor for the more than 8-percent decrease in heart disease mortality between 1988 and 1989?
Uma wanted to test her hypothesis that fescue grass grows best under red light. Independent variables, such as size of fescue grass plants, soil type, number of plants, and length of exposure to light were kept identical for both the experimental and control groups. Uma exposed the experimental group to red, green, and blue light and the control group only to sunlight. She took daily measurements of plant height for the next three weeks.
During the second week, Uma noticed that 8 of the 10 plants that she had exposed to red light looked a little wilted. She increased the daily water amount for these 8 plants. At the end of the experiment, she concluded that fescue grass grows best under red light.
What is a possible flaw in Uma’s experiment?
Earth’s system is observed by noting changes and interactions of the oceans, land, the atmosphere, and organisms. Some of these changes and interactions happen daily, while others take place over long periods of time.
Which of the following changes and interactions happen on a daily basis?
A community is a population of all living things, or organisms, in a given area. Communities consist of organisms that may interact with one another. When two organisms, each from a different species, interact, their interaction can be categorized as one of the following:
Which category describes an interaction where a tapeworm feeds on intestinal material in the human body?
Daily weather patterns are often the result of temperature differences, patterns of air flow, relative humidity, condensation, or evaporation. A warm front forms when a warmer air mass pushes a cold air mass ahead of it. Precipitation over a large area can occur along a warm front.
Based on this information and diagram, what would most likely happen if a mass of hot, humid air encountered a colder air mass in the northern portion of Earth’s surface?
Yeast is a fungus that is used in making bread. As the yeast cells reproduce and feed, they ferment sugars to produce ethyl alcohol and carbon dioxide gas. The carbon dioxide forms bubbles in the dough, causing the dough to rise. How fast the dough rises depends on temperature.
Three portions of dough weighing exactly the same are allowed to rise for 45 minutes at three different temperatures. At the end of forty-five minutes, the volume of each portion is measured. The results of the experiment are listed in the table at the left.
Based on the chart, which statement is an accurate conclusion?
-- 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 student’s 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?
A home built on the California coast was once 150 yards from the shore. Now it is only 75 yards away.
Which process is most likely responsible for this change?
Water quality is affected when nutrients such as nitrogen and phosphorus drain into streams and lakes. These compounds promote the growth of algae, which, when they die and decay, may result in the depletion of oxygen in the water. The chart below indicates the relative content of nitrogen and phosphorus in several substances.
Based on the information and chart, which situation is LEAST likely to lead to an excess of nitrogen and phosphorus in the water?
Scientist Alexander Fleming was looking for a chemical that would be effective in combating bacteria. In order to test various chemicals, he grew cultures of the bacteria, Staphylococcus. One day in 1928, as he was working in his laboratory, Fleming noticed that one of his culture plates had mold growing on it. Many people might have thrown the plate away thinking that it was useless, but Fleming did not. He noticed something—that no bacteria were growing near the mold. He hypothesized that the mold was killing the bacteria. Fleming had just discovered penicillin.
He began working to separate the chemical that killed the bacteria from all the other chemicals in the mold. Unfortunately, he was unable to do so. However, in 1940, two chemists, Ernst Chain and Howard Florey, did manage to separate the chemical penicillin. In 1945, all three men were awarded the Nobel Prize in Medicine.
Based on the information, which statement represents the best conclusion?
Based on the diagram,
Which statement represents a conclusion about the movement of the horses in their circular paths?
Yolanda knows copper is sometimes found in lava flows. Where would she be most successful in finding copper?
The formation of a large lake in a cold northern climate was the result of a massive piece of ice scraping out a huge depression in the ground.
Which process best explains this change?
Petroleum is a complex mixture of hydrocarbon molecules (molecules containing hydrogen and carbon). This hydrocarbon mixture varies greatly in composition. Different hydrocarbons have different boiling points and can be separated on this basis. The more carbon atoms in the chain, the higher the boiling point.
Based on this information, which hydrocarbon has the lowest boiling point?
Blood typing is essentially a chemical reaction that provides data so that blood may be safely transfused from one person to another. The basic objective is to avoid “clumping” that could occur in the recipient when the wrong blood type is received. These “clumps” of red blood cells could block arteries or veins affecting the blood flow to critical body organs, like the heart or the brain.
Exhibit:
Based on the chart and the information, which blood type will not form clumps with either Anti-A reagent serum or the Anti-B reagent serum?
The digestive tract of an animal that eats meat is about four times the length of the animal’s body. In an animal that eats plants, the digestive tract is about twenty times the length of the animal’s body.
Which animal would be expected to have the longest digestive tract relative to its body length?
TESTED 22 Sep 2025
