ICAS Interpreting Scientific Data Questions and Answers — Questions and Answers
Question 1: A group of students investigated how the amount of light affects the growth of radish plants. They used a single light source and placed identical pots with radish seeds at different distances from it. The table below shows the average height of the seedlings in each pot after 10 days. | Pot | Distance from Light (cm) | Average Seedling Height (cm) | |---|---|---| | 1 | 10 | 12 | | 2 | 20 | 9 | | 3 | 30 | 6 | | 4 | 40 | 3 | Which statement is the most valid conclusion from this experiment?
- Radish plants grow taller when they receive more light. (Correct answer)
- The radish seedlings in Pot 4 were unhealthy.
- All radish plants need at least 12 cm of light to grow.
- The distance from light does not affect radish plant growth.
Correct answer: Radish plants grow taller when they receive more light.
The data clearly shows an inverse relationship between the distance from the light source and the average seedling height. As the distance decreases (meaning the light intensity increases), the average height of the seedlings increases. Pot 1, at the shortest distance (10 cm), had the tallest seedlings (12 cm), while Pot 4, at the farthest distance (40 cm), had the shortest seedlings (3 cm).
Question 2: The graph below shows the population of two different species, A and B, in a shared habitat over 15 years. What is the most likely relationship between Species A and Species B based on the data? [A line graph showing two lines. The Y-axis is 'Population' and the X-axis is 'Year'. The line for Species A (predator) consistently rises after the line for Species B (prey) rises, and falls after the line for Species B falls. The peaks and troughs of Species A's line lag behind Species B's line.]
- Species A is a parasite, and Species B is its host.
- Species A and Species B have a mutualistic relationship.
- Species A is a predator, and Species B is its prey. (Correct answer)
- Species A and Species B compete for the same resources.
Correct answer: Species A is a predator, and Species B is its prey.
The graph displays a classic predator-prey cycle. The population of the prey (Species B) increases first, providing more food for the predator (Species A). This leads to an increase in the predator population. As the predator population rises, they consume more prey, causing the prey population to decline. The subsequent lack of food then causes the predator population to decline, allowing the prey population to recover, and the cycle repeats.
Question 3: A scientist tests the effectiveness of four different disinfectants (W, X, Y, Z) on a specific type of bacteria. She prepares four identical petri dishes with the same concentration of bacteria. She then adds an equal amount of each disinfectant to a different dish. After 24 hours, she measures the area in the dish where bacteria did not grow (the zone of inhibition). The results are shown in the bar chart. [A bar chart with 'Disinfectant' on the X-axis and 'Zone of Inhibition (mm²)' on the Y-axis. The bar for W is at 50, X is at 120, Y is at 80, and Z is at 45.] Based on the chart, which of the following is the most accurate statement?
- Disinfectant Y is more effective than Disinfectant X.
- Disinfectant Z is the least effective at stopping bacterial growth. (Correct answer)
- Disinfectant W is twice as effective as Disinfectant Z.
- A combination of W and Z would be more effective than X.
Correct answer: Disinfectant Z is the least effective at stopping bacterial growth.
The 'zone of inhibition' represents the area where the disinfectant was effective at stopping bacterial growth. A larger zone means greater effectiveness. Disinfectant Z has the smallest bar on the chart (45 mm²), indicating it was the least effective of the four tested. Disinfectant X had the largest zone (120 mm²) and was therefore the most effective.
Question 4: A student measures the temperature of a beaker of water as it is heated over a Bunsen burner. They record the temperature every two minutes. The table shows their results. | Time (minutes) | Temperature (°C) | |---|---| | 0 | 20 | | 2 | 35 | | 4 | 50 | | 6 | 65 | | 8 | 80 | | 10 | 95 | If the student continues to heat the water under the same conditions, what is the most likely temperature at the 12-minute mark?
- 100°C (Correct answer)
- 105°C
- 110°C
- 115°C
Correct answer: 100°C
The data shows a consistent increase of 15°C every 2 minutes. Continuing this pattern from 10 minutes (95°C) would lead to 110°C at 12 minutes. However, this is a measurement of water being heated. Water's boiling point at standard pressure is 100°C. Once water reaches its boiling point, the temperature will plateau and remain at 100°C as the liquid turns into steam, even with continued heating. Therefore, the temperature will stop rising at 100°C.
Question 5: The diagram below shows a simplified food web for an arctic ecosystem. [A food web diagram showing: Algae is eaten by Krill. Krill is eaten by Arctic Cod and Seals. Arctic Cod is eaten by Seals. Seals are eaten by Polar Bears.] If a disease significantly reduces the population of seals, which of the following is the most probable immediate consequence?
- The krill population will increase.
- The polar bear population will increase.
- The Arctic cod population will decrease.
- The polar bear population will decrease. (Correct answer)
Correct answer: The polar bear population will decrease.
According to the food web, polar bears rely on seals as their primary food source. A significant reduction in the seal population would directly reduce the amount of available food for polar bears, leading to a decrease in the polar bear population due to starvation or migration.
Question 6: A study was conducted to determine the effect of soil pH on the number of flowers produced by a certain plant species. The results are presented in the scatter plot graph below. [A scatter plot graph with 'Soil pH' on the X-axis (from 4 to 10) and 'Average Number of Flowers' on the Y-axis. The data points form an inverted 'U' shape, starting low at pH 4, peaking around pH 6.5-7, and decreasing again towards pH 10.] What conclusion can be drawn from the data presented in the graph?
- As the soil pH increases, the number of flowers consistently increases.
- This plant species produces the most flowers in highly acidic soil.
- The number of flowers is not affected by soil pH.
- This plant species produces the most flowers in soil that is close to neutral pH. (Correct answer)
Correct answer: This plant species produces the most flowers in soil that is close to neutral pH.
The graph shows that the average number of flowers is highest when the soil pH is between 6.5 and 7, which is considered a neutral pH range. At pH values that are more acidic (lower pH) or more alkaline/basic (higher pH), the number of flowers produced is significantly lower. This indicates an optimal pH range for flower production.
ICAS Interpreting Scientific Data Questions and Answers
A group of students investigated how the amount of light affects the growth of radish plants.
They used a single light source and placed identical pots with radish seeds at different distances from it.
The table below shows the average height of the seedlings in each pot after 10 days.
| Pot | Distance from Light (cm) | Average Seedling Height (cm) |
|---|---|---|
| 1 | 10 | 12 |
| 2 | 20 | 9 |
| 3 | 30 | 6 |
| 4 | 40 | 3 |
Which statement is the most valid conclusion from this experiment?