ICAS Interpreting Scientific Data 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?

Accepted Answer

Radish plants grow taller when they receive more light.

Answer

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.]

Accepted Answer

Species A is a predator, and Species B is its prey.

Answer

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?

Accepted Answer

Disinfectant Z is the least effective at stopping bacterial growth.

Answer

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?

Accepted Answer

100°C

Answer

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?

Accepted Answer

The polar bear population will decrease.

Answer

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.

(ICAS) ICAS Practice Test Practice Test

(ICAS) ICAS Practice Test Practice Test

ICAS Interpreting Scientific Data Questions and Answers