prokaryotes

Question 1

Draw and label the structure of a typical prokaryotic cell (8)

Answer 1

Cell wall (made of murein - a glycoprotein);
Cell surface membrane;
Free circular DNA molecule in cytoplasm;
Ribosomes (70S ribosomes); Cytoplasm;
Capsule surrounding the cell wall (in some);
One or more plasmids (in some); One or more flagella (in some)

Question 2

What structures are present in all prokaryotic cells? (5)

Answer 2

Cell wall (made of murein - a glycoprotein);
Cell surface membrane;
Free circular DNA molecule in cytoplasm;
Ribosomes (70s ribosomes); Cytoplasm

Question 3

What structures are only present in some prokaryotic cells? (3)

Answer 3

Capsule surrounding the cell wall;

One or more plasmids;

One or more flagella

Question 4

Describe the DNA of prokaryotic cells (4)

Answer 4

No nucleus is present;

DNA is free in the cytoplasm;

Circular DNA;

Not attached to any histone proteins

Question 5

Describe the properties of plasmids found in prokaryotic cells (3)

Answer 5

Contain antibiotic resistance genes (amongst others);

Plasmids are able to be passed between prokaryotes;

Some prokaryotic cells have several plasmids, others have no plasmids

Question 6

Compare prokaryotic cells and eukaryotic cells (5)

Answer 6

Prokaryotic cells lack a nucleus, whereas eukaryotic cells have a nucleus;

Prokaryotic cells have 70S ribosomes, eukaryotic cells have 80S ribosomes;

Prokaryotic cells are smaller;

Prokaryotic cells have circular DNA, eukaryotic cells have linear DNA;

Prokaryotic cells have no membrane-bound organelles

Question 7

What is the difference in the type of ribosome in bacterial and human cells? (2)

Answer 7

Bacterial cells have 70S ribosomes whereas, human cells have 80S ribosomes