TEKS 8.12

The student knows that cycles exist in Earth systems.

The student can predict the results of modifying the Earth's nitrogen, water, and carbon cycles.

TEKS 8.14

The student knows that natural events and human activities can alter Earth systems.

The student can analyze how natural or human events may hae contributed to the extinction of some species.

The student can describe how human activities have modified soil, water, and air quality.