2.11 Origins of Cell Compartmentalization

• One key difference between prokaryotic and eukaryotic cells is the presence of organelles
• Steps of the endosymbiotic theory for the origin of mitochondria

  1️⃣ A prokaryotic cell engulfs another prokaryotic cell.

  2️⃣ The engulfed cell becomes a symbiotic organelle.

  3️⃣ The host cell compartmentalizes cellular processes.
• Mitochondria and chloroplasts have their own DNA and ribosomes
• Match the feature with its explanation according to the endosymbiotic theory:

  Origin of Organelles ↔️ Mitochondria and chloroplasts were once independent prokaryotic organisms

  Symbiotic Relationship ↔️ Engulfed prokaryotes and host cell formed a mutually beneficial relationship

  Genetic Evidence ↔️ Mitochondria and chloroplasts have their own DNA
• What is the term for the division of a cell into specialized structures with distinct functions?

  Compartmentalization
• Organelles facilitate specialized cellular tasks.


  True
• Which two organelles are believed to have originated from prokaryotic organisms according to the endosymbiotic theory?

  Mitochondria and chloroplasts
• What is one benefit of compartmentalization in eukaryotic cells?

  Increased efficiency
• The endosymbiotic theory explains the origins of all organelles in eukaryotic cells.

  False
• Mitochondria and chloroplasts were once independent prokaryotic
• Match the feature of the endosymbiotic theory with its evidence:

  Genetic Evidence ↔️ Mitochondria and chloroplasts have their own DNA and ribosomes

  Compartmentalization ↔️ Increases efficiency and functional diversity

  Symbiotic Relationship ↔️ Prokaryotes provide specialized functions

  Origin of Organelles ↔️ Mitochondria and chloroplasts were engulfed by larger cells
• What genetic evidence supports the endosymbiotic theory?

  Own DNA and ribosomes
• The genetic code of mitochondrial DNA is more similar to prokaryotes than the host cell's nucleus.


  True
• Mitochondria and chloroplasts contain circular DNA and 70S ribosomes
• What is the main difference between prokaryotic and eukaryotic cells regarding organelles?

  Prokaryotic cells lack organelles
• What are the specialized structures within cells that perform specific functions called?

  Organelles
• Mitochondria and chloroplasts have circular DNA
• Prokaryotic cells lack membrane-bound organelles
• Match the cell type with its cell wall composition:

  Prokaryotic Cells ↔️ Peptidoglycan

  Plant Cells ↔️ Cellulose

  Fungal Cells ↔️ Chitin
• The DNA in prokaryotic cells is circular
• What key feature distinguishes eukaryotic cells from prokaryotic cells?

  Presence of a nucleus
• The cell membrane acts as a selective barrier to regulate molecule movement.
• The cell membrane maintains the internal environment of the cell.


  True
• Match the organelle with its primary function:

  Nucleus ↔️ Controls cellular activities

  Mitochondria ↔️ Energy production

  Chloroplasts ↔️ Photosynthesis

  Endoplasmic Reticulum ↔️ Protein synthesis

  Golgi Apparatus ↔️ Protein packaging
• Cell compartmentalization increases cellular efficiency.


  True
• The endosymbiotic theory suggests that mitochondria and chloroplasts originated from prokaryotic organisms.
• What genetic evidence supports the endosymbiotic theory?

  Similar DNA to prokaryotes
• What is the advantage of compartmentalization in cells?

  Increased function
• What type of DNA do mitochondria and chloroplasts have?

  Circular
• Mitochondria and chloroplasts have double membranes similar to the cell walls of prokaryotes
• The incorporation of organelles through endosymbiosis increased cellular efficiency and functional diversity


  True
• What is the primary role of the cell membrane?

  Selective barrier
• The selective permeability of the cell membrane allows organelles to perform specialized tasks
• What is the function of mitochondria in cellular respiration?

  Energy production
• Chloroplasts in plant cells allow the efficient conversion of sunlight into energy
• What does the endosymbiotic theory propose regarding the origin of mitochondria and chloroplasts?

  Prokaryotic organisms
• The symbiotic relationship between the host cell and the engulfed prokaryotes was mutually beneficial.


  True
• Order the steps involved in the endosymbiotic theory according to evolutionary time:

  1️⃣ Prokaryotic organisms exist independently

  2️⃣ Prokaryotic organisms are engulfed by larger cells

  3️⃣ Symbiotic relationship forms

  4️⃣ Organelles become compartmentalized

  5️⃣ Eukaryotic cells evolve
• Mitochondria and chloroplasts have DNA and ribosomes similar to prokaryotes
• What structural feature of mitochondria and chloroplasts resembles prokaryotic cell walls?

  Double membranes