1. Bell Work Question for 1/24/13
1. Which of these would be measured to determine the density of the polar bear population in Canada?
The number of bears per square kilometer
The mass of the bears at the Arctic Circle
The total number of bears minus the juvenile bears
The total number of bears seen per day

2. Bell Work Question for 1/25/13
2. Which sentence best states the importance of using control groups?
Control groups provide a method by which statistical variability can be reduced.
Control groups allow comparison between subjects receiving a treatment and those receiving no treatment.
Control groups eliminate the need for statistical tests and simplify calculations.
Control groups eliminate the need for large sample sizes, reducing the number of measurements needed.

3. Bell Work Question for 1/28/13
3. Which procedure would most likely provide valid results in a test to determine if drug A would be effective in treating cancer in white mice?
(1) injecting 1 mL of drug A into 100 white mice with cancer
(2) injecting 1 mL of drug A into 100 white mice with cancer and 0.5 mL of drug X into 100 white mice without cancer
(3) injecting 1 mL of drug A into 100 white mice with cancer and 0.5 mL of drug X into another group of 100 white mice with cancer
(4) injecting 1 mL of drug A into 100 white mice with cancer and 1 mL of distilled water into another group of 100 white mice with cancer

4. Bell Work Question for 1/29/13
4. A scientist designed an experiment to test the effect of temperature on bacterial growth. He grew three different cultures of the bacterium E. coli under three heat lamps at different temperatures. What was the independent variable in this experiment?
Length of the experiment
Number of bacteria
Reproduction rate
Temperature

5. Bell Work Question for 1/30/13
5. Data about the climate in an ecosystem were collected for 30 years. Which hypothesis about a population of eagles could be made based on the climate data collected
Eagle chick survival is directly related to annual rainfall amounts.
An outbreak of disease in 1987 killed 82% of the eagle population.
Eagles remain with the same mate throughout their lifetime.
Mortality of eagles from pesticides after was less than 5%.

6. Bell Work Question for 1/31/13
6. In an experiment, the height of several plants was recorded daily in millimeters. Which tool would be the most accurate and appropriate for this measurement?
Yardstick
Graduated cylinder
Digital scale
Metric ruler

7. Bell Work Question for 2/4/13
7. In a forest ecosystem, which is an abiotic factor? A the amount of rainfall B the size of the deer C the type of trees D the number of birds

8. Bell Work Question for 2/6/13
8. Which situation would result in the greatest increase in the human population? A decreased birth rate and increased death rate B increased infant mortality and decreased death rate C decreased death rate and increased birth rate D increased birth rate and increased infant mortality

9. Bell Work Question for 2/7/13
9. In the carbon cycle, atmospheric carbon dioxide is converted into organic material by which process? A cellular respiration B decomposition C photosynthesis D transpiration

10. Bell Work Question for 2/8/13
10. Why do ecosystems rarely contain more than a few trophic levels? A Energy transfer efficiency is high. B Energy transfer efficiency is low. C Energy amounts remain constant. D Energy cannot flow through levels.

11. Bell Work Question for 2/12/13
11. Recent climate data suggests a global warming trend. The most likely cause could be an increase in which gas? A oxygen B carbon dioxide C nitrogen D hydrogen sulfide

12. Bell Work Question for 2/14/13
12. Which component of a stable ecosystem can not
be recycled?
Oxygen
Energy
Water
nitrogen

13. Bell Work Question for 2/15/13
13. Silt and nutrients from eroding farmland flow into a lake. As a result, which will most likely increase first? A fish population B shore vegetation C algae growth D dissolved oxygen

14. Bell Work Question for 2/21/13
14. The main difference between prokaryotic and eukaryotic cells is that —
eukaryotic cells have a smaller cell nucleus
prokaryotic cells are always much larger
prokaryotic cells do not have a plasma membrane
eukaryotic cells have a more advanced cellular organization

15. Bell Work Question for 2/27/13
15. What structure is common to all five kingdoms of living organisms?
Cell wall
DNA
Nucleus
Mitochondria

16. Bell Work Question for 2/28/13
16. When an animal eats, food stays in the stomach for a period of time. When a unicellular organism, such as Paramecium, takes in food, the food is contained in which organelle?
Chloroplast
Mitochondrion
Vacuole
Nucleus

17. Bell Work Question for 3/1/13
17. The function of most proteins depends primarily on the A. type and order of amino acids B. environment of the organism C. availability of starch molecules D. nutritional habits of the organism

18. Bell Work Question for 3/4/13
18. Enzymes are classified as which of the following biological organic compounds?
A carbohydrates
B lipids
C nucleic acids
D proteins

19. Bell Work Question for 3/5/13
19. Why do cells need buffering agents? A to maintain constant internal environment at a pH of 10 B to minimize the changes in pH of the internal environment C to function properly in an extremely basic internal environment D to function properly in an extremely acid internal environment

20. Bell Work Question for 3/6/13
20. The sweet taste of freshly picked corn is due to the high sugar content in the kernels. Enzyme action converts about 50% of the sugar to starch within one day after picking. To preserve its sweetness, the freshly picked corn is immersed in boiling water for a few minutes, and then cooled. Which statement most likely explains why the boiled corn kernels remain sweet?
Boiling destroys sugar molecules so they cannot be converted to starch.
Boiling kills a fungus on the corn that is needed to convert sugar to starch.
Boiling activates the enzyme that converts amino acids to sugar.
Boiling deactivates the enzyme responsible for converting sugar to starch.

21. Bell Work Question for 3/7/13
21. Individuals who lack lactase are unable to break down the sugar lactose. Which term best describes lactase? A enzyme B fatty acid C lipid D starch

22. Bell Work Question for 3/11/13
22. Damage to which structure will most directly disrupt water balance within a single-celled organism?
ribosome
Nucleus
cell membrane
chloroplast

23. Bell Work Question for 3/12/13
23. Which cell process will move substances against a concentration gradient? A diffusion B facilitated diffusion C osmosis D active transport

24. Bell Work Question for 3/13/13
24. Placing wilted lettuce in cold water will make it crisp again. Which statement best describes what happens to restore the lettuce to its original condition? A Water left the lettuce cells by diffusion. B Water entered the cells of the lettuce by osmosis. C Osmosis caused salts to enter the lettuce cells. D Salts in the leaf caused water to leave the cells.

25. Bell Work Question for 3/14/13
25. Some peeled pieces of apple were placed in distilled water and some in very salty water. The cells in the apple pieces will —
lose water in both solutions
gain water in the distilled water and lose water in the salty water
gain water in both solutions
lose water in the distilled water and gain water in the salty water

26. Bell Work Question for 3/15/13
26. Certain poisons are toxic to organisms because they interfere with the function of enzymes in mitochondria. This results directly in the inability of the cell to
(1) store information
(2) build proteins
(3) release energy from nutrients
(4) dispose of metabolic wastes

27. Bell Work Question for 3/18/13
27. If several species of carnivores are removed from an ecosystem, the most likely effect on the ecosystem will be
(1) an increase in the kinds of autotrophs
(2) a decrease in the number of abiotic factors
(3) a decrease in stability among populations
(4) an increase in the rate of succession