STAAR® EOC Biology

Don't mess with Texas…EOC.

  • Practice questions: 132
  • Practice exams: 3
  • Pages of review: 39
  • Videos: 22

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Ah, biology, the study of life. It's a great opening line—just ask every biology textbook ever written—but what comes next? As it turns out, a whole lot. Prep for the Texas Biology End-of-Course Assessment with Shmoop's guide to the exam. We'll discuss why we're completely outnumbered by our cells, how hominids managed to make it to the big dance, and how to deal with the other organisms fighting for elbow room on the big blue marble we call home. We'll also cover just about everything in between…including more about pea flowers than you ever wanted to know.

What's Inside Shmoop's Online Texas EOC Biology Prep

Shmoop is a labor of love from folks who are really, really into learning. Our test prep resources will help you prepare for exams with comprehensive, engaging, and frankly hilarious materials that bring the test to life. No, not like that. Put down those torches.

Here, you'll find…

  • extreme topic review (for the extreme student)
  • practice drills to drill concepts into your brain
  • multiple full-length practice exams to get that full-length experience
  • test-taking tips and strategies from experts who know what they're talking about
  • step-by-step guides to taking down essay questions
  • chances to earn Shmoints and climb the leaderboard

Sample Content


Some tumors only grow to a certain size and then stop with no explanation. (Since cells can't talk to scientists, we understand the lack of communication.) Other tumors continue to grow until they are removed or until the organism dies. Still other tumors will spread throughout the body when a few cells break off into the blood stream or lymph nodes, deposit themselves somewhere else in the body, and then set up shop wherever they land. A tumor that spreads is called malignant (From the Latin "mal," bad ) cancer.

Cancer Triggers

Anything that disrupts DNA could lead to cancer, but the chances are higher if the disruption is at a site that codes for a control protein or a repair protein. If the genes for a repair protein and a control protein both mutate in the same cell—but the cell doesn't die on its own—then cancer is most likely to occur.

The two word roots you will most see to describe cancer are "carcino" and "onco." DNA disruptions can occur when chemical bonds are broken by high-frequency radiation such as sunlight or radioactive emissions. They may also occur when chemicals interfere with the placement of nucleotides during replication. These chemicals that cause cancer are called carcinogens (from the Latin "carcino," crab + "gen," birth). Guess those old Romans thought that tumors looked like crabs growing underneath a person's skin, which is…frankly kind of creepy, old Romans.

Additionally, some viruses cause cancer by purposely attacking control genes. These viruses are called oncoviruses (from the Greek "onco," bulk + "virus," poison).

Cancer-causing mutations may also be introduced when cellular enzymes just make a silly mistake. This is why cancer is the leading cause of death among the elderly; the longer life span, the higher the chance of mistakes. You can't teach an old cell new tricks, and in some cases it's only a matter of time before a random mistake is made during cell division.

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