NumicornNumicornLearn, solve, progress

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

3. Test

California High School CAST Science Practice Questions

A 10-question California High School CAST Science practice set on earth and space science, 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

What drives convection in Earth’s mantle?

Please select an answer first.

Correct answer: A

The correct answer is Differences in temperature and density cause material to move..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Heating creates density differences that can drive convection within Earth’s interior.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Heating creates density differences that can drive convection within Earth’s interior.

2. QuestionMultiple choice

Which evidence supports the theory of plate tectonics?

Please select an answer first.

Correct answer: B

The correct answer is Matching fossils and rock formations are found on continents now separated by oceans..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Matching geological evidence across separated continents supports past movement.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Matching geological evidence across separated continents supports past movement.

3. QuestionMultiple choice

How does carbon dioxide contribute to the greenhouse effect?

Please select an answer first.

Correct answer: C

The correct answer is It absorbs and re-emits some infrared radiation in the atmosphere..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Greenhouse gases interact with outgoing infrared radiation and affect energy balance.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Greenhouse gases interact with outgoing infrared radiation and affect energy balance.

4. QuestionMultiple choice

What happens to a star after it uses much of the hydrogen in its core?

Please select an answer first.

Correct answer: D

The correct answer is Its structure and energy production can change as it evolves..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Changes in core fuel alter the balance between pressure and gravity during stellar evolution.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Changes in core fuel alter the balance between pressure and gravity during stellar evolution.

5. QuestionMultiple choice

Why do scientists use redshift to study distant galaxies?

Please select an answer first.

Correct answer: A

The correct answer is The shift can provide evidence about their motion relative to Earth..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: The change in observed wavelength can reveal relative motion through the Doppler effect.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

The change in observed wavelength can reveal relative motion through the Doppler effect.

6. QuestionMultiple choice

What causes tides on Earth most strongly?

Please select an answer first.

Correct answer: B

The correct answer is Gravitational interactions with the Moon and the Sun..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: The gravity of the Moon and Sun produces regular changes in ocean water levels.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

The gravity of the Moon and Sun produces regular changes in ocean water levels.

7. QuestionMultiple choice

Which process removes carbon dioxide from the atmosphere for a period of time?

Please select an answer first.

Correct answer: C

The correct answer is Photosynthesis by plants and algae..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Photosynthesis takes in carbon dioxide and stores carbon in organic molecules.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Photosynthesis takes in carbon dioxide and stores carbon in organic molecules.

8. QuestionMultiple choice

Why can an ice core provide evidence of past atmospheric conditions?

Please select an answer first.

Correct answer: D

The correct answer is Trapped gas bubbles preserve samples of ancient air..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Gas bubbles and chemical layers in ice can preserve information about past environments.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Gas bubbles and chemical layers in ice can preserve information about past environments.

9. QuestionMultiple choice

What is the main source of energy driving most weather and climate systems on Earth?

Please select an answer first.

Correct answer: A

The correct answer is Radiation from the Sun..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Solar radiation supplies most of the energy that drives atmospheric and surface processes.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Solar radiation supplies most of the energy that drives atmospheric and surface processes.

10. QuestionMultiple choice

How can scientists estimate the age of a rock using radioactive isotopes?

Please select an answer first.

Correct answer: B

The correct answer is They compare parent and daughter isotope amounts using a known decay rate..

  1. Identify the science idea: Determine whether the task focuses on life, physical, Earth and space, environmental, or engineering science.
  2. Use the evidence: Radioactive decay provides a measurable rate for estimating elapsed time.
  3. Check the choice: Make sure the answer explains the mechanism, pattern, or evidence rather than only repeating a detail.

Radioactive decay provides a measurable rate for estimating elapsed time.

Previous testNext test

Choose your next study path

Elementary School Tests

Build foundational reading, math, science, and social studies skills for Grades 1–5.

Middle School Tests

Review grade-level ELA, math, science, and social studies skills for Grades 6–8.

High School Tests

Explore course and assessment preparation for Grades 9–12.

Pomodoro Timer

Use focused study intervals to work through your next practice set.

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.