Cell Structure

• What are the two types of cells?

  Eukaryotic - Plants and Animals

  Prokaryotic - Bacteria
• What is the differences between prokaryotic and eukaryotic cells?

  Prokaryotic are much smaller then Eukaryotic

  Eukaroytic contain membrane-bound organelles and a nucleus, Prokaryotes do not
• What is the prokarytoic cell wall composed of?

  Peptidoglycan
• How is genetic information stored in a bacterial cell?

  Can be stored in Plasmids

  Or in chromosomal DNA which is contained in the cytoplasm.
• What are Plasmids?


  Small, circular loops of DNA found free in the cytoplasm.

  Carry genes that provide genetic advantages such as antibiotic resistance.
• What is a millimeter?

  1 × 10⁻³ m
• What is a micrometer?

  $1 × 10⁻⁶$m
• What is a nanometer?

  $1 × 10⁻⁹$ m
• What is the difference in magnitude of 100µm and 100nm?

  100µm = 1 × 10⁻⁴ m

  100nm = 1 × 10⁻⁷ m

  -4-(-7) = -4 + 7 = 3
• What is the difference in magnitude of 100µm and 100nm? (WORK OUT)

  3
• List components that both animal and plant cells have.

  Nucleus

  Cell Membrane

  Ribosomes

  Cytoplasm

  Mitochondria
• List the 3 components that are exclusive to plant cells.

  Cell Wall

  Permanent Vacoule

  Chloroplasts
• What are the two functions of the nucleus?

  Controlling cellular activites

  Storing genetic information
• Other than storing genetic information what else is the nucleus of a cell responsible for?

  Controlling cellular activites
• Describe the structure of the cytoplasm.

  -Fluid component of the cell

  -Contains organelles, enzymes and dissolved ions and nutrients
• What is the function of the cytoplasm?

  Site of cellular reactions e.g first stage of respiration

  Transport medium
• What is the function of the cell membrane?

  Controls entry and exit of material in the cell.
• What is the function of the mitochondria?

  Site of areobic respiration
• What is the function of ribosomes?

  Joins amino acids in a specific order during the translation for the synthesis of proteins
• What is the plant cell wall made of?

  Cellulose
• What is the function of the plant cell wall?

  Provides strength

  Prevents the cell bursting when water enters via osmosis.
• What does the permanent vacoule contain?

  Cell sap
• What is the function of the permanent vacoule?

  Supports the cell and maintains it turgidity.
• What is the function of chloroplasts?

  Photosynthesis
• How are sperm cells adpated to their function?

  Haploid nucleus contains genetic information

  Tail enables movement

  Mitochondria provide energy for tail movement

  Acrosome contains enzymes that dissolve the egg cell membrane.
• How are nerve cells adapted to their function?

  Long Axon - allows electrical impluses to be transmitted all over the body from the CNS

  Dendrites - recieve impluses from other nerve, muscle and gland cells

  Myelin Sheath - insultates the axon and speeds up the transmission of impluses across the nerve cell.
• Describe how muscle cells in animals are adapted to their function.

  Arrangement of protein fliment allows them to slide over each other to provide muscle contractions

  Mitochondria provides energy for contractions

  Merged cells in Sketeal muscle allows muscle fibre contraction in unison.
• How are root hair cells in plants adapted to their function?

  Large surface area - absorbs nutrients and water from surrounding soil

  Thin walls - do not restrict water absorption
• Describe how xylem cells in plants are adapted to their function.

  No upper or lower margins between cells to provide a continuous route for water to flow.

  Thick, woody side walls strengthen structure to prevent collapse
• Describe how Pholem cells in plants are adapted to their function.

  Sieve plates let dissolved amino acids and sugars be transported.

  Companion cells provide energy needed for active transport of substances along the pholem
• What is cell differenation?

  The process by which a cell becomes specialised for a specific function.
• Why is cell differentation important?

  Allows production of vital tissues and organs
• At what point in their life style do most animal cells differentiate?

  Early in their life cycle
• For how long do plant cells maintain the ability to differentiate?

  Throughout their entire life cycle.
• What is the purpose of cell divison in mature animals?


  Repair and replacement of cells.
• Define magnification.


  The number of times an image appears compared to the size of real objects.
• Define resolution.

  The smallest distance between two objects that can be distinguished.
• How does a light microscope work?


  Passes a beam of light through a specimen which travels through the eyepiece lens, allowing the specimen to be observed.
• What are the advantages of light microscopes.

  -Cheap

  -Easy to use

  -Portable

  -Observe both dead and living specimens
• What is the disadvantage of light microscopes.

  Limited resolution