#2 MORE AP Bio Unit 2 Exam

• What is the core structure of cilia and flagella?


  It has a "9 + 2" pattern of microtubules.
• What is the function of dynein arms in cilia and flagella?


  They are motor proteins that use ATP to facilitate movement along microtubules.
• What is the structure of the basal body of cilia and flagella?


  It has a "9 + 0" pattern of microtubules.
• How do cilia function in cellular movement?


  Cilia move fluid over the cell surface or propel single-celled organisms through water.
• What is the primary function of flagella?


  Flagella propel cells in liquids by whipping back and forth.
• What are the three major components of the cytoskeleton?


  Microfilaments, microtubules, and intermediate filaments.
• What are the structures and functions of microfilaments?


  • Structure: Two intertwined strands of actin (globular protein).
  • Function: Provide structural support, cell movement, and contraction (e.g., muscle contraction, amoeba).
• What are the structures and functions of microtubules?


  • Structure: Hollow tubes made from tubulin proteins (alpha + beta dimers).
  • Function: Provide structural support and assist in cellular movement (e.g., cilia and flagella).
• What are the structures and functions of intermediate filaments?


  • Structure: Intermediate thickness compared to microfilaments and microtubules.
  • Function: Provide structural support and maintain organelle positions; more stable than the other two.
• What is the composition of the phospholipid bilayer?


  It consists of hydrophilic heads and two hydrophobic tails.
• What types of molecules can easily pass through the phospholipid bilayer?


  Small, nonpolar molecules can easily pass through.
• What type of molecules can pass through the membrane but with difficulty?


  Small, polar molecules can pass but with more difficulty.
• What type of molecules cannot pass through the phospholipid bilayer?


  Large, polar molecules cannot pass through.
• What is the role of transport proteins in the cell membrane?


  They provide pathways for molecules that cannot pass through the bilayer.
• What are integral membrane proteins?


  They are embedded within the membrane and interact with both hydrophobic and hydrophilic environments.
• What are peripheral membrane proteins?


  They are loosely attached to the membrane surface.
• How do membrane proteins extend into and out of the cell?


  They have amphipathic regions that interact with both hydrophobic and hydrophilic environments.
• What is the primary structure of the cell wall?

  It is made of cellulose microfibrils.
• What is the function of the cell wall?


  It provides rigidity, maintains cell shape, and prevents excessive water uptake.
• What is the extracellular matrix composed of?


  It is composed of glycoproteins and proteoglycans.
• What is the function of collagen in the extracellular matrix?


  Collagen provides strength and structural support to surrounding cells.
• What role do integrins play in the extracellular matrix?


  Integrins connect the ECM to the cytoskeleton, facilitating signal transmission.
• What are the types of intercellular junctions and their functions?

  • Tight junctions: Seal spaces between cells to prevent leakage.
  • Desmosomes: Provide mechanical adhesion between cells.
  • Gap junctions: Allow ions and small molecules to pass for communication.
  • Plasmodesmata: Channels in plant cells for molecular travel between cells.
• What is the function of the cell wall?


  It provides structural support and protection.
• What is the function of the plasma membrane?


  It controls the movement of substances in and out of the cell.
• What is the role of ribosomes?


  They are the sites of protein synthesis.
• What is the function of the nucleoid in prokaryotic cells?


  It is where the cell's DNA is located.
• What is the function of flagella?


  They provide movement for the cell.
• What is the function of pili in prokaryotic cells?


  Pili help in attachment to surfaces.
• What is the function of the capsule in prokaryotic cells?


  It provides protection and helps the cell stick to surfaces.
• How does the ratio of surface area to volume limit cell size?


  As cells grow, volume increases faster than surface area, limiting efficiency.
• What are the downward limits of cell size?


  A cell that is too small cannot accommodate essential components like DNA and organelles.
• What are the upward limits of cell size?

  A cell that is too large has a decreased surface area to volume ratio, hindering nutrient exchange.
• How do organelles contribute to cellular complexity?


  • Organelles compartmentalize metabolic processes.
  • They allow for specialization and increased efficiency.
  • They enable multiple processes to occur simultaneously.
  • They contribute to the development of specialized cells in multicellular organisms.
• What is the function of the nucleus in a eukaryotic cell?


  It contains DNA and controls cell activities by regulating gene expression.
• What are ribosomes made of?


  Ribosomes are made of rRNA and proteins.
• What is the function of the rough endoplasmic reticulum?


  It synthesizes proteins for secretion or membrane insertion.
• What is the function of the smooth endoplasmic reticulum?


  It is involved in lipid synthesis, detoxification, and calcium storage.
• What is the role of the Golgi apparatus?


  It modifies, sorts, and packages proteins and lipids from the ER into vesicles.
• What is the function of mitochondria?


  They generate ATP through cellular respiration.