Cell Biology Quiz

Prokaryotic Cells

• Lack a nucleus and membrane-bound organelles.
• Examples include Bacteria and Archaea.
• DNA is found in a nucleoid region within the cell.
• Simple structure features a plasma membrane, cell wall, and may have flagella or pili.
• Generally smaller than eukaryotic cells.

Eukaryotic Cells

• Contain a nucleus and membrane-bound organelles.
• Examples include Animal cells, Plant cells, Fungal cells, and Protist cells.
• DNA is contained within the nucleus.
• Complex structure includes organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus.

Specific Cell Types

Animal Cells

• Lack a cell wall, have irregular shapes, and often contain lysosomes and centrioles.
• Key organelles include:
  • Nucleus for storing genetic information.
  • Mitochondria for ATP production.
  • Endoplasmic Reticulum (ER) for protein (rough ER) and lipid (smooth ER) synthesis.
  • Golgi Apparatus for modulating, sorting, and packaging proteins and lipids.
  • Lysosomes for digesting macromolecules and cellular debris.

Plant Cells

• Characterized by a rigid cell wall, chloroplasts, and a large central vacuole.
• Key organelles include:
  • Chloroplasts as the site for photosynthesis.
  • Cell Wall for structural support and protection.
  • Large Central Vacuole for maintaining turgor pressure and storing nutrients and waste products.

Fungal Cells

• Similar to plant cells but have a cell wall made of chitin instead of cellulose.
• Key organelles include:
  • Nucleus for housing genetic material.
  • Vacuoles for storing nutrients and waste.
  • Cell Wall composed of chitin.

Protist Cells

• A diverse group exhibiting characteristics of animal, plant, or fungal cells.
• Notable examples:
  • Amoebas: Unicellular and move using pseudopodia.
  • Paramecia: Unicellular and move using cilia.
  • Algae: Photosynthetic organisms with chloroplasts.

Specialized Cell Types

• Specialized cells have unique structures and functions to perform specific roles within an organism, differing morphologically and biochemically from non-specialized cells.

Examples of Specialized Cells

• Nerve Cells (Neurons)

  • Function: Transmit electrical impulses throughout the nervous system.
  • Structure includes axons (carry signals away), dendrites (receive signals), and synaptic terminals (release neurotransmitters).

• Muscle Cells

  • Function: Facilitate movement through contraction.
  • Types include:
    • Skeletal Muscle Cells: Striated, voluntary, attached to bones.
    • Cardiac Muscle Cells: Striated, involuntary, found in the heart.
    • Smooth Muscle Cells: Non-striated, involuntary, located in internal organ walls.

• Blood Cells

  • Types:
    • Red Blood Cells (Erythrocytes) for carrying oxygen.
    • White Blood Cells (Leukocytes) for immune responses.
    • Platelets (Thrombocytes) for blood clotting.

• Epithelial Cells

  • Function: Form protective layers and barriers on surfaces and organs.
  • Types include:
    • Squamous Epithelium: Thin, flat cells for skin and blood vessels.
    • Cuboidal Epithelium: Cube-shaped cells for ducts and glands.
    • Columnar Epithelium: Tall cells in the digestive tract for absorption and secretion.

• Sperm Cells

  • Function: Fertilize egg cells during reproduction.
  • Structure includes:
    • Flagellum: Tail-like propelling structure.
    • Acrosome: Cap-like structure with enzymes to penetrate the egg.

• Plant Cells

  • Function: Perform photosynthesis and provide structural support.
  • Specialized structures include:
    • Chloroplasts for capturing light energy.
    • Rigid Cell Wall for strength.
    • Central Vacuole for maintaining turgor pressure and nutrient storage.