Two test tubes were filled with a solution of bromthymol blue. A student exhaled through a straw into each tube, and the bromthymol blue turned yellow. An aquatic plant was placed into each tube, and the tubes were corked. One tube was placed in the dark, and one was placed in direct sunlight. The yellow solution in the tube in sunlight turned blue, while the one in the dark remained yellow.Which statement best explains why the solution in the tube placed in sunlight returned to a blue color?   a. Oxygen was used in photosynthesis.   b. Oxygen was removed by respiration.   c. Carbon dioxide was removed by photosynthesis.   d. Carbon dioxide was produced by respiration.

Biology students studied the effect of temperature on the production of carbon dioxide by yeast cells.

•IDENTIFY IV AND DV•WHAT TYPE OF GRAPH•LABEL AXIS?•CONTROL GROUP(S)•EXPERIMENTAL GROUP(S)•CONSTANTS

Biology students studied the effect of temperature on the production of carbon dioxide by yeast cells. A diagram of their experiment is shown.

They counted the number of carbon dioxide bubbles produced by the yeast at different temperatures. A graph of their results is shown.

According to the data above, which of these is the best conclusion that can be made from this experiment?

a. CO2 production is not influenced by temperature

b. Yeast cells produce more CO2 at lower temperatures

c. The higher the temperature, the greater the production of CO2

d. CO2 production first increases then decreases as temperature rises

IV? DV? HYPOTHESIS?

Best Conclusion isa. ATP production is independent of sugar availability b. The amount of cellular respiration is constant in muscle cells c. ATP is only produced when sugar concentration is above 4 g/L d. Cellular respiration increases as sugar concentration increases.

It was observed that in one cove the bass caught were of an unusually small mass. An electric generating plant releases hot water into the cove. Students measured the oxygen levels in the cove at the hot water release point, and every 100 yards along the stream of hot water until it reached the main part of the lake.

Which of these hypotheses had the students most likely formed before taking their measurements?

a. The electric generating plant releases hot water into the cove.

  b. The small mass of the fish is caused by lack of oxygen in the water.

  c. The fish in the cove do not have enough food.

  d. The small mass of the fish is caused by plants clogging the cove.

IV? DV? Axis on graphs

• It was observed that in one cove the bass caught were of an unusually small mass. An electric generating plant releases hot water into the cove. Students measured the oxygen levels in the cove at the hot water release point, and every 100 yards along the stream of hot water until it reached the main part of the lake.

IV, DV, hypothesis, constants• When the bacterium Serratia marcescens is grown on a

sterile medium in a perti dish at 30 oC, the bacterial colonies are cream colored. When the same bacterium is cultured under identical conditions, except at a temperature of 25 oC, the colonies are brick red. This difference in color is most likely due to the

  a. types of nutrients in the culture medium

  b. sterilization of the culture medium

  c. effect of temperature on the expression of the gene for color

  d. effect of colony size on the synthesis of color pigments

Data shows that normally about 1% of the frogs are deformed, but in ponds where pesticides are used on surrounding land, as many as 69% of the frogs were deformed.

•HYPOTHESIS, IV, DV, CONTROL GROUP(S), EXPERIMENTAL GROUP(S)

A developmental biologist, questions whether a chemical could be the culprit because there were no deformed fish or other deformed animals found in the ponds where deformed frogs were captured. He believes parasites are the cause. When examining a three-legged frog from Vermont, the biologist found tiny parasitic flatworms packed into the joint where a leg was missing.

•WHAT’S WRONG WITH THIS EXPERIMENT?

•A biologist in a laboratory reports a new discovery based on experimental results. If the experimental results are valid, biologists in other laboratories should be able to

  a. repeat the experiment with a different variable and obtain the same results

  b. perform the same experiment and obtain different results

  c. perform the same experiment and obtain the same results

  d. perform the same experiment under different experimental conditions and obtain the same results

IV, DV, hypothesis

IV, DV, hypothesis

HYPOTHESIS, IV, DV

•Officials in Maryland have used the presence of lesions on fish as a reason for closing coastal waterways to fishing and all other water activities. They thought that the lesions on the dead fish were caused by a type of microscopic algae known as Pfiesteria. The toxins produced by Pfiesteria are believed to cause headaches, fatigue, and short-term memory loss in humans who come into contact with contaminated waterways.

IV, DV, HYPOTHESIS, CONSTANTS, CONCLUSION

WHAT’S WRONG WITH GRAPH?

•A student wants to view cells under a compound microscope at a total magnification of 400X. If the eyepiece is 10X, which of the following objective lenses should be used?

  a. 4X

  b. 10X

  c. 40X

  d. 100X

IV, UNITS OF DV, HYPOTHESIS

•WHAT INFERENCE MIGHT YOU MAKE?

The hypothesis best supported by this graph is that these beetles are most active when the area is

The data table shows the growth of two bean plants over several weeks using four different fertilizers. The experimental data would be more valid if which of the following variables was included in the experiment?

a. a fifth fertilizer was testedb. only one plant was testedc. the plants were grown at variable temperaturesd. a control without fertilizer was included for each plant

•Which sentence below best states the importance of using control groups in experiments?

a. Control groups allow comparison between subjects receiving a treatment and those receiving no treatment.

b. Control groups eliminate the need for large sample sizes, reducing the number of measurements needed.

c. Control groups eliminate the need for statistical tests and simplify calculations.

d. Control groups provide a method by which statistical variability can be reduced.

Which hypothesis is best supported by observation of this animal?

O   a. This animal spends much of its time digging.O   b. This animal usually hunts for food at night.O   c. This animal is a good swimmer.O   d. This animal has poor hearing.

•IV, DV, HYPOTHESIS, CONCLUSION, CONSTANTS, AXIS OF GRAPH

•IDENTIFY ALL HYPO-, HYPER-, AND ISOTONIC SOLUTIONS. IDENTIFY EACH PROBABLE CHANGE IN CELL SIZE. EXPLAIN

•The most valid and reliable test of this hypothesis would include an experimental group of pine seeds recovered from a fire area and a group of pine seeds that were

O   a. germinated after a fire

O   b. tolerant of fire

O   c. found before a fire

O   d. placed in a fire

Jan consistently read the volume of liquids as shown. How would this practice impact her work?

a. Her measurements would lack precision. b. Her measurements would be too high. c. Her measurements would be too low. d. Her measurements would be very accurate.

What is being measured?What tool is being used?What unit is

most likely being used?

Carmen conducted an experiment to determine if listening to different types of music would affect a person's pulse

•DV, IV, EXPERIMENTAL GROUP(S), CONTROL GROUP(S), CONSTANTS

•Cells are the functional units that make up tissues. Tissues then become the functional units that make up

O   a. enzymes

O   b. organs

O   c. other cells

O   d. DNA

IV, DV, CONSTANTS, EXPERIMENTAL GROUP(S), CONTROL GROUP(S),

HYPOTHESIS, AXIS OF GRAPH

•Hody performed an experiment on four equal-sized tomato plants. She placed each tomato plant in a separate container. Jody gave each plant the same amount of light and nutrients, different amounts of water, and frequently measured the amount of oxygen produced by each tomato plant.

DV, IV, HYPOTHESIS, CONTROL GROUP(S), CONSTANTS, EXPERIMENTAL

GROUP(S)

A biologist is studying a species of crab. He hypothesized that if a crab has larger pincer claws, then it will have greater reproductive success. He placed 50 crabs with small pincers and 50 crabs with large pincers together in an isolated area that closely resembled their natural environment. He observed several generations of the crabs over the next ten years.

•If hypothesis is supported, what did he observe?

•DV, IV

A scientist performed an experiment to determine the best level of light intensity for photosynthesis in an aquatic plant. He varied the light intensity and measured the amount of a gas produced by the plant at each level of light intensity.

•CONSTANTS, CONTROL GROUP(S), EXPERIMENTAL GROUP(S), IV, DV, HYPOTHESIS, LABEL GRAPH AXIS