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California CAST · High School · Science

California High School CAST Science Practice Test

Build California High School CAST Science readiness with five focused 10-question practice sets covering life science, physical science, Earth and space science, environmental systems, engineering, and data.

High School CAST Science practice sets

This California High School CAST Science Practice Test page provides five short practice sets with 10 original multiple-choice questions each. The sets support supplemental review across life science, physical science, Earth and space science, environmental systems, engineering design, data analysis, and scientific reasoning.

Science skills covered

  • Population dynamics, ecosystems, mutations, meiosis, natural selection, photosynthesis, decomposers, speciation, alleles, and homeostasis
  • Particle motion, reaction energy, reaction rates, conservation of atoms, circuits, graphs, gravity, waves, and catalysts
  • Mantle convection, plate tectonics, greenhouse gases, stars, redshift, tides, carbon cycling, ice cores, solar energy, and radioactive dating
  • Food webs, wetlands, eutrophication, fisheries, biodiversity, stormwater, climate feedbacks, conservation, ocean chemistry, and data scales
  • Engineering optimization, repeated trials, extrapolation, controlled variables, model revision, correlation, uncertainty, unexpected results, constraints, and outliers

How to use this page

Complete one 10-question set at a time. Identify the evidence, explain the mechanism, and review every solution before moving to the next set.

This is supplemental State Test Practice, State Assessment Practice, and Standardized Test Practice. It does not replace current California Department of Education guidance, official CAST blueprints, accommodations, or testing schedules.

For the broader California assessment hub, visit California State Assessments.

Select a test

5 Tests
1. Test2. Test3. Test4. Test5. Test

5. Test

California High School CAST Science Practice Questions

A 10-question California High School CAST Science practice set on engineering, data, and scientific reasoning, with answers and explanations.

Read each science task carefully, choose one answer, and review the explanation after responding.

10 Questions
0/10 Questions0 %
Correct 0
Incorrect 0
Unanswered 10
1. QuestionMultiple choice

A design must reduce water use while keeping crop yield high. Which approach best represents engineering optimization?

Please select an answer first.

Correct answer: A

The correct answer is Compare several designs using water use, yield, cost, and reliability data..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Optimization requires comparing solutions against relevant constraints and criteria.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Optimization requires comparing solutions against relevant constraints and criteria.

2. QuestionMultiple choice

Why are repeated trials important in an investigation?

Please select an answer first.

Correct answer: B

The correct answer is They help identify variation and increase confidence in a pattern..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Repeated trials help distinguish a consistent effect from random variation.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Repeated trials help distinguish a consistent effect from random variation.

3. QuestionMultiple choice

A graph shows a curved relationship between fertilizer amount and plant growth. What should a scientist avoid doing?

Please select an answer first.

Correct answer: C

The correct answer is Assuming growth will continue increasing at the same rate outside the measured range..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Extrapolation beyond the data can be unreliable when the relationship is not known.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Extrapolation beyond the data can be unreliable when the relationship is not known.

4. QuestionMultiple choice

Which change would improve the fairness of a test comparing two solar panels?

Please select an answer first.

Correct answer: D

The correct answer is Use the same light source, angle, time, and measurement method for both panels..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Keeping relevant conditions constant makes the comparison more valid.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Keeping relevant conditions constant makes the comparison more valid.

5. QuestionMultiple choice

A model predicts a bridge will support a certain load, but testing shows it fails. What is the best next step?

Please select an answer first.

Correct answer: A

The correct answer is Use the evidence to revise the design or model and test it again..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Engineering is iterative and uses test results to improve solutions.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Engineering is iterative and uses test results to improve solutions.

6. QuestionMultiple choice

What does a correlation between two variables show?

Please select an answer first.

Correct answer: B

The correct answer is They change together in a pattern, but correlation alone does not prove causation..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Correlation describes an association; additional evidence is needed to establish cause.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Correlation describes an association; additional evidence is needed to establish cause.

7. QuestionMultiple choice

Why should uncertainty be reported with a measurement?

Please select an answer first.

Correct answer: C

The correct answer is It communicates the range within which the measured value may reasonably lie..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Uncertainty communicates limits of precision and helps readers interpret results.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Uncertainty communicates limits of precision and helps readers interpret results.

8. QuestionMultiple choice

A student finds an unexpected result that conflicts with the hypothesis. What is the most scientific response?

Please select an answer first.

Correct answer: D

The correct answer is Check the procedure and data, then consider revising the explanation..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Unexpected results should be investigated rather than hidden or altered.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Unexpected results should be investigated rather than hidden or altered.

9. QuestionMultiple choice

Which design constraint is a limit that an engineer must work within?

Please select an answer first.

Correct answer: A

The correct answer is A maximum budget for materials..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Constraints such as budget limit which solutions are feasible.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Constraints such as budget limit which solutions are feasible.

10. QuestionMultiple choice

A data table contains one value far outside the pattern of all other trials. What should be done first?

Please select an answer first.

Correct answer: B

The correct answer is Check for recording or measurement error and examine the original observation..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: An apparent outlier should be verified before it is included or excluded from analysis.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

An apparent outlier should be verified before it is included or excluded from analysis.

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Frequently asked questions about California High School CAST Science Practice Test

Which Science skills are covered?

The page covers high school life science, physical science, Earth and space science, environmental systems, engineering practices, data analysis, and scientific reasoning.

How many questions are included?

There are five practice sets with 10 questions each, for 50 questions in total. Each set can be completed separately.

Are these official CAST questions?

No. These are original supplemental practice questions. Check the latest California Department of Education information for official materials, standards, accommodations, and policies.