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California CAST · Grades 5, 8 & High School · Science

California CAST Science Practice Test

Build California CAST Science readiness with five focused 10-question practice sets covering life science, physical science, Earth and space science, engineering, and data analysis for Grades 5, 8, and high school.

CAST Science practice sets

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

Science skills covered

  • Photosynthesis, natural selection, cells, heredity, ecosystems, energy flow, mutations, evolution, and experimental variables
  • Chemical and physical change, thermal energy, circuits, atomic structure, reactions, waves, collisions, work, and ions
  • Plate tectonics, climate, Moon phases, greenhouse gases, fossils, tides, volcanic ash, renewable resources, and redshift
  • Controlled experiments, engineering criteria and constraints, models, repeated trials, efficiency, controls, and claim-evidence-reasoning
  • Associations, systems, phase changes, surface energy, biodiversity, gas relationships, conservation of matter, simulations, carrying capacity, and uncertainty

How to use this page

Complete one 10-question set at a time. Identify the evidence, describe the mechanism, and review every explanation before moving to the next set. Use the grade-specific pages when you want more focused practice for Grade 5, Grade 8, or high school.

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.

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

5. Test

California CAST Science Practice Questions

A 10-question California CAST Science practice set on crosscutting concepts and data analysis, with answers and explanations for Grades 5, 8, and high school review.

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 graph shows that atmospheric carbon dioxide and average temperature both rise over several decades. What can the graph support?

Please select an answer first.

Correct answer: A

The correct answer is The variables have a positive association over the period shown..

  1. Identify the science idea: Determine whether the task focuses on a life, physical, Earth and space, engineering, or data concept.
  2. Use the evidence: The graph shows an association, but additional evidence is needed to establish the full causal relationship.
  3. Check the choice: Make sure the answer explains the observed pattern, mechanism, or evidence rather than merely repeating a detail.

The graph shows an association, but additional evidence is needed to establish the full causal relationship.

2. QuestionMultiple choice

A food web loses a top predator. Which effect is most plausible?

Please select an answer first.

Correct answer: B

The correct answer is Some prey populations may increase and alter lower levels of the web..

  1. Identify the science idea: Determine whether the task focuses on a life, physical, Earth and space, engineering, or data concept.
  2. Use the evidence: Removing a predator can change prey numbers and create cascading effects through the food web.
  3. Check the choice: Make sure the answer explains the observed pattern, mechanism, or evidence rather than merely repeating a detail.

Removing a predator can change prey numbers and create cascading effects through the food web.

3. QuestionMultiple choice

A material changes from solid to liquid while its temperature stays constant during the change. What is happening to the energy?

Please select an answer first.

Correct answer: C

The correct answer is Energy is being used to change particle arrangement rather than raise temperature..

  1. Identify the science idea: Determine whether the task focuses on a life, physical, Earth and space, engineering, or data concept.
  2. Use the evidence: During a phase change, added energy can change intermolecular arrangement while temperature remains constant.
  3. Check the choice: Make sure the answer explains the observed pattern, mechanism, or evidence rather than merely repeating a detail.

During a phase change, added energy can change intermolecular arrangement while temperature remains constant.

4. QuestionMultiple choice

A city replaces dark pavement with a reflective surface and measures lower surface temperatures. Which system interaction is being investigated?

Please select an answer first.

Correct answer: D

The correct answer is How surface properties affect energy transfer between Earth’s surface and the atmosphere..

  1. Identify the science idea: Determine whether the task focuses on a life, physical, Earth and space, engineering, or data concept.
  2. Use the evidence: The design changes surface reflection and tests its effect on thermal energy in the local system.
  3. Check the choice: Make sure the answer explains the observed pattern, mechanism, or evidence rather than merely repeating a detail.

The design changes surface reflection and tests its effect on thermal energy in the local system.

5. QuestionMultiple choice

A species has a small population and low genetic diversity. Why may it be vulnerable to disease?

Please select an answer first.

Correct answer: A

The correct answer is Fewer genetic differences may mean fewer individuals have resistance traits..

  1. Identify the science idea: Determine whether the task focuses on a life, physical, Earth and space, engineering, or data concept.
  2. Use the evidence: Limited variation reduces the chance that some individuals carry traits that help them resist a new disease.
  3. Check the choice: Make sure the answer explains the observed pattern, mechanism, or evidence rather than merely repeating a detail.

Limited variation reduces the chance that some individuals carry traits that help them resist a new disease.

6. QuestionMultiple choice

A data table shows that increasing pressure decreases the volume of a gas at constant temperature. Which relationship is described?

Please select an answer first.

Correct answer: B

The correct answer is An inverse relationship..

  1. Identify the science idea: Determine whether the task focuses on a life, physical, Earth and space, engineering, or data concept.
  2. Use the evidence: As pressure increases, volume decreases, so the variables have an inverse relationship.
  3. Check the choice: Make sure the answer explains the observed pattern, mechanism, or evidence rather than merely repeating a detail.

As pressure increases, volume decreases, so the variables have an inverse relationship.

7. QuestionMultiple choice

Which observation is evidence of conservation of matter in a closed chemical reaction?

Please select an answer first.

Correct answer: C

The correct answer is The total mass before the reaction equals the total mass after it..

  1. Identify the science idea: Determine whether the task focuses on a life, physical, Earth and space, engineering, or data concept.
  2. Use the evidence: In a closed system, atoms are rearranged but the total mass remains constant.
  3. Check the choice: Make sure the answer explains the observed pattern, mechanism, or evidence rather than merely repeating a detail.

In a closed system, atoms are rearranged but the total mass remains constant.

8. QuestionMultiple choice

A community compares two flood-control designs using computer simulations before construction. What is a benefit of the model?

Please select an answer first.

Correct answer: D

The correct answer is It allows consequences to be explored with less cost and risk than a full-scale build..

  1. Identify the science idea: Determine whether the task focuses on a life, physical, Earth and space, engineering, or data concept.
  2. Use the evidence: Models can help test scenarios and identify possible problems before implementation.
  3. Check the choice: Make sure the answer explains the observed pattern, mechanism, or evidence rather than merely repeating a detail.

Models can help test scenarios and identify possible problems before implementation.

9. QuestionMultiple choice

A graph of a population rises rapidly and then levels off near the habitat’s carrying capacity. What does the leveling suggest?

Please select an answer first.

Correct answer: A

The correct answer is Limiting factors are restricting further population growth..

  1. Identify the science idea: Determine whether the task focuses on a life, physical, Earth and space, engineering, or data concept.
  2. Use the evidence: Food, space, disease, or other limiting factors can keep a population near carrying capacity.
  3. Check the choice: Make sure the answer explains the observed pattern, mechanism, or evidence rather than merely repeating a detail.

Food, space, disease, or other limiting factors can keep a population near carrying capacity.

10. QuestionMultiple choice

Why is it useful to state uncertainty when reporting a scientific measurement?

Please select an answer first.

Correct answer: B

The correct answer is It communicates the limits of the measurement and prevents false precision..

  1. Identify the science idea: Determine whether the task focuses on a life, physical, Earth and space, engineering, or data concept.
  2. Use the evidence: Reporting uncertainty helps readers judge how precise and reliable the result is.
  3. Check the choice: Make sure the answer explains the observed pattern, mechanism, or evidence rather than merely repeating a detail.

Reporting uncertainty helps readers judge how precise and reliable the result is.

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Frequently asked questions about California CAST Science Practice Test

Which grades does this CAST Science practice page support?

This hub provides mixed supplemental practice for the California CAST assessment areas used in Grade 5, Grade 8, and high school. Grade-specific pages can provide more targeted review.

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.