The TAKS tests a student's understanding of what science is and how it works. Questions for this objective focus on the scientific method and representing data with graphs. Students must demonstrate an understanding of what makes a good scientific question, how to formulate a hypothesis, how to set up an experiment with variables and controls, how to collect data, how to organize and express data, how to analyze data and how to evaluate their original hypothesis. Questions include graph analysis, choosing the best hypothesis to answer a hypothetical question and identifying ways hypothetical experiments could have been conducted better.
This objective centers on biology. Students should understand how DNA molecules are constructed; what mRNA does; what genetic mutations are and their effect on evolution; what genetic engineering is; the differences between plant, animal and bacterial cells and how the human organ systems interconnect. Questions include identifying the purpose of specific organelles, recognizing DNA and mRNA processes, identifying the functions of body systems and basic genetic analysis.
Students are tested on their understanding of the effect of the environment on living things, both as individuals and when grouped by species and habitat. Students should understand natural selection, speciation, inherited traits, adaptation, the nature of an ecosystem, an ecosystem's energy pyramid and biomass pyramid, food chains and webs, the oxygen-carbon dioxide cycle and population-limiting factors. Questions ask students to analyze evolutionary trends, identify effects of newly introduced substances on the food chain, compare biomasses and identify interrelationships within an ecosystem.
This section of the test focuses on basic chemistry. Students should be familiar with the construction of atoms, how to read the periodic table, the properties of metals, nonmetals and metalloids, valence electrons, ionic bonds and compounds, chemical formulas, covalent bonds, chemical reactions, balancing chemical equations, conservation of mass, solutions and solubility, the pH scale, polar molecules and the properties of water, including adhesion, cohesion, viscosity, buoyancy and density. Questions involve recognizing properties of elements, explaining chemical reactions and predicting conduction levels.
The final objective tested on the TAKS is basic physics. Students should understand balanced and unbalanced forces, Newton's laws, friction, conservation of energy, waves, the difference between speed and frequency, wave interference, electromagnetic waves, energy sources and how to use the formulas for power, efficiency, acceleration, work and mechanical, kinetic and potential energy. The questions test the students' abilities to solve problems using physics formulas, understanding of the behavior of waves and by analysis of the efficiency of various energy sources.