Ch 6-A Tour of the Cell part 1

Question 1

Role of Cells in Organisms

Answer 1

Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions Cells have many parts, each with a different function.

Question 2

Light Microscopy

Answer 2

• Visible light pass through specimen and lenses
• Lens refract the light and image is magnified

Question 3

Electron Microscopy

Answer 3

• Uses beam of electrons
• Magnify up to 100,000 times
• Types
  
  • Scanning electron microscopes (SEM)
  • Transmission electron microscopes (TEM)

Question 4

Cell Theory

Answer 4

The unified cell theory states that; all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells.

Question 5

Prokaryotic organisms

Answer 5

• Characterized by having
  
  • No nucleus
  • DNA in an unbound region called the nucleoid
  • No membrane-bound organells
• Ex: Bacteria and Archaea

Question 6

Eukaryotic Organisms

Answer 6

• Characterized by having
  
  • DNA in a nucleus - bounded by a double membrane
  • Membrane-bound organells
• Much larger than prokaryotic cell

Question 7

Sizes of different cells

Answer 7

Describe

Question 8

Eukaryotic Cells

Answer 8

Describe Structure

Question 9

Animal and Plant cells

Answer 9

• Only in plant
  
  • Chloroplasts
  • Central vacuole
  • Cell wall
  • Plasmodesmata (channels in cell walls; connect adjacent cells)
• Only in animal
  
  • Lysosomes
  • Centrioles
  • Flagella (present in some plant sperm)

Question 10

Nucleus and Ribosomes

Answer 10

• Nucleus
  
  • Contain cell’s DNA - Chromosomes
  • Nuclear envelope - lipid bilayer
    
    • Nuclear pore
• Ribosomes
  
  • Protein factories
  • Made up of Ribosomal RNA (rRNA) and Protein
  • Produced in Nucleolus
  • Composed of large and small subunit