1. What is the best definition of a Nucleoid ?
   1. Organelles made of protein and RNA that direct protein synthesis.
   2. A dense region of DNA in a prokaryotic cell.
   3. The basic structural and functional unit of all organisms.
   4. A phospholipid bilayer that surrounds the cell
2. Plasma membrane is best described as….
   1. A phospholipid bilayer that surrounds the cell
   2. Organelles made of protein and RNA that direct protein synthesis.
   3. A rigid non-cellulose structure that surrounds cells of bacteria
   4. A dense region of DNA in a prokaryotic cell.
3. Which statement best describes a prokaryote cell wall ?
   1. Hair-like protein structures, that allow bacteria to attach to things.
   2. A phospholipid bilayer that surrounds the cell
   3. A dense region of DNA in a prokaryotic cell.
   4. A rigid non-cellulose structure that surrounds cells of bacteria

Data analysis question

1. Calculate the length of this prokaryote cell using the scale bar. (2 marks)

(click the eye icon to show the model answer)

Written question

1. Compare the structure of a prokaryote cell with an eukaryote cell (4 marks)
   (click the eye icon to show the model answer)
    

   One mark for each correct comparison: up to a max of four.

   Here are  two examples…

   A prokaryote has DNA in a nucleoid region but a eukaryote has a membrane bound nucleus.

   Prokaryotes contain 70s ribosomes, but eukaryotes have 80s ribosomes.

   Don't accept statements which do not compare the same thing,
    e.g. Prokaryotes have 70s ribosomes, and eukaryotes have mitochondria.

   Accept the following pairs of structures in a comparison.

   Prokaryote	Eukaryote
   Nucleoid	Nucleus
   Free Ribosomes 70s	Free ribosomes 80s & attached ribosomes on rER
   non-cellulose wall	plants have cellulose wall
   no membrane bound organelles	membrane bound organelles eg mitochondria
   Similarities in both	Cytoplasm, plasma membrane DNA