Prokaryotic And Eukaryotic Cells

Question 1

What’s the name for bacteria which are adapted to living in extremes of salinity, pH and temperature.

Answer 1

Extremophiles- usually of the domain archaea.

Question 2

What are unicellular organisms

Answer 2

Only consist of one cell e.g. bacteria

Question 3

What’s the difference between the DNA of a prokaryotic cell

Answer 3

Generally have one molecule of DNA, a chromosome, which is supercoiled to make it more compact. The genes on the chromosome are often grouped into operons, meaning a number of genes are switched on or off at the same time.

Question 4

Difference between ribosomes in eukaryotes and prokaryotes

Answer 4

Prokaryotes-70S
Eukaryotes-80S

Question 5

Describe the structure of the prokaryotic cell wall

Answer 5

Cell wall made from peptidoglycan. Complex polymer formed from amino acids and sugars.

Question 6

Describe the prokaryotic flagella

Answer 6

The flagella of prokaryotes is thinner than eukaryotes and does not have the 9+2 arrangement. The energy to rotate the filament that forms the flagellum is supplied from the process of chemiosmosis, not from ATP as in eukaryotic cells. The flagellum is attached to the cell membrane of a bacterium by a basal body and rotated by a molecular motor.

Question 7

Describe the differences between a prokaryotic and eukaryotic cell- nucleus, DNA, DNA organisation, extra chromosomal DNA, organelles, cell wall, ribosomes, cytoskeleton, reproduction, cell type, cell-surface membrane.

Answer 7

Nucleus- P( not present) E(present)

DNA-P(circular) E(linear)

DNA organisation-P(proteins fold and condense DNA) E(associated with proteins called histones)

Extra chromosomal DNA- P(circular DNA called plasmids) E(only present in certain organelles eg chloroplasts and mitochondria)

Organelles-P-non-membrane bound) E(both membrane and non-membrane bound)

Cell wall- P(peptidoglycan) E(chitin in fungi, cellulose in plants, not present in animals)

Cytoskeleton- P(present) E(present, more complex)

Ribosomes - P(70S) E(80S)

Reproduction- P( binary fission) E(asexual or sexual)

Cell type- P(unicellular) E(unicellular and multicellular)

Cell surface membrane- present in both