Topic B1- Cells

• What did Robert Hooke observe when he looked at a slice of cork under a microscope?

  He saw the building blocks of many organisms, which he called cells.
• What are the two main types of organisms based on cell structure?

  Organisms can be Prokaryotes or Eukaryotes.
• What are the two types of cells mentioned in the study material?

  Prokaryotic cells and Eukaryotic cells.
• What is a characteristic of Eukaryotic cells?

  Eukaryotic cells are complex and include organelles such as a nucleus.
• What is a characteristic of Prokaryotic cells?

  Prokaryotic cells are simple and usually single-celled organisms.
• What are the subcellular structures found in most animal cells?

  • Nucleus: contains genetic material that controls cell activities.
  • Cytoplasm: gel-like substance where most chemical reactions occur.
  • Cell membrane: holds the cell together and controls what goes in and out.
  • Mitochondria: where most reactions for aerobic respiration take place.
  • Ribosomes: where proteins are made.
• What additional structures do plant cells have compared to animal cells?

  • Rigid cell wall: made of cellulose, supports and strengthens the cell.
  • Permanent vacuole: contains cell sap, a weak solution of sugar and salts.
  • Chloroplasts: where photosynthesis occurs, containing chlorophyll to absorb light.
• What is the function of the cell wall in plant cells?

  The cell wall supports and strengthens the cell.
• What is the role of chloroplasts in plant cells?

  Chloroplasts are where photosynthesis occurs, making food for the plant.
• What do bacterial cells lack compared to eukaryotic cells?

  Bacterial cells do not have chloroplasts or mitochondria.
• What is unique about the DNA in bacterial cells?

  Bacterial cells have a single circular strand of DNA that floats freely in the cytoplasm.
• What are plasmids in bacterial cells?

  Plasmids are small rings of DNA that may be present in bacterial cells.
• Compare the structures of prokaryotic and eukaryotic cells.

  Prokaryotic Cells:

  • Simple structure
  • No true nucleus
  • Usually unicellular
  • Smaller in size

  
  

  Eukaryotic Cells:

  • Complex structure
  • True nucleus present
  • Can be unicellular or multicellular
  • Larger in size