AP Biology Questions on Cellular Structure and the Cytoskeleton

📚 Quick Study Guide

• 🧬 Cellular Structures: Eukaryotic cells contain membrane-bound organelles such as the nucleus, endoplasmic reticulum (ER), Golgi apparatus, mitochondria, and lysosomes. Prokaryotic cells lack these organelles.
• 🧱 Cell Wall: Provides structural support and protection in plant cells (cellulose), bacteria (peptidoglycan), and fungi (chitin).
• 🦠 Plasma Membrane: A selectively permeable barrier composed of a phospholipid bilayer with embedded proteins. Functions in transport, cell signaling, and cell adhesion.
• ⚡ Cytoskeleton: A network of protein fibers that provides structural support, facilitates cell movement, and intracellular transport. It consists of:
• 🕸️ Microfilaments: Composed of actin, involved in cell motility, muscle contraction, and cytokinesis.
• 💪 Intermediate Filaments: Provide structural support and mechanical strength to cells and tissues.
• 🚂 Microtubules: Composed of tubulin, involved in chromosome movement during cell division, intracellular transport, and cell shape.
• 💡 Key Functions of the Cytoskeleton: Cell shape maintenance, motility (cilia & flagella), intracellular transport (motor proteins), and cell division.
• 🔬 Techniques for Studying Cellular Structures: Microscopy (light, electron), cell fractionation, and immunofluorescence.

🧪 Practice Quiz

1. Which of the following is NOT a component of the cytoskeleton?
   1. Microfilaments
   2. Intermediate filaments
   3. Microtubules
   4. Cellulose
2. What is the main function of the Golgi apparatus?
   1. Protein synthesis
   2. Lipid synthesis
   3. Protein modification and sorting
   4. Energy production
3. Which structure is primarily responsible for maintaining cell shape in plant cells?
   1. Plasma membrane
   2. Cell wall
   3. Cytoskeleton
   4. Nucleus
4. Which of the following structures is found in prokaryotic cells?
   1. Mitochondria
   2. Endoplasmic reticulum
   3. Nucleus
   4. Ribosomes
5. What protein comprises microfilaments?
   1. Tubulin
   2. Actin
   3. Keratin
   4. Myosin
6. Which cytoskeletal element is involved in the movement of chromosomes during cell division?
   1. Microfilaments
   2. Intermediate filaments
   3. Microtubules
   4. All of the above
7. Which of the following is NOT a function of the plasma membrane?
   1. Cell signaling
   2. Energy production
   3. Transport of molecules
   4. Cell adhesion