Biology STAAR (State of Texas Assessments of Academic Readiness) Practice Test

Disable ads (and more) with a membership for a one time $2.99 payment

Prepare for the Biology STAAR Exam with our interactive test. Utilize flashcards and multiple-choice questions with detailed explanations and hints. Ace your exam confidently!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.


What is the function of the plasma membrane?

  1. To facilitate energy production

  2. To store genetic information

  3. To serve as a boundary and control permeability

  4. To conduct cellular respiration

The correct answer is: To serve as a boundary and control permeability

The plasma membrane's primary function is to serve as a boundary that separates the interior of the cell from its external environment, effectively maintaining the integrity of the cell. It acts as a selective barrier, controlling the entry and exit of substances, which is essential for maintaining homeostasis within the cell. The plasma membrane is composed of a lipid bilayer with embedded proteins, allowing it to regulate the movement of ions, nutrients, and waste products. By controlling permeability, the plasma membrane ensures that essential molecules can enter the cell while keeping potentially harmful substances out. It also plays a vital role in communication and signaling between cells, enabling the cell to respond to various stimuli. The other options relate to cellular functions but do not describe the fundamental role of the plasma membrane itself.