Zoology Module Three

Exam One

Prokaryotic cell

single celled, bacteria and archaea, have no nucleus, DNA in nucleoid, no membrane-bound organelles, cytoplasm bound by plasma membrane, have one circular chromosome, reproduce through binary fission

Eukaryotic cell

protists, fungi, plants, and animals, DNA in nucleus bound by double membrane, membrane-bound organelles, cytoplasm inbetween nucleus and membrane

All cells have

plasma membrane, cytoplasm (cytosol), chromosomes, ribosomes

Prokaryotic cell shapes

cocci (spheres), bacilli (rods), spirals

Peptidoglycan

sugar polymers cross linked with polypeptides

Gram stain

used to classify bacteria by cell wall composition

Gram positive bacteria

simpler walls, large amount of peptidoglycan

Gram negative bacteria

less peptidoglycan, more complex with outer membrane that contains lipopolysaccharides, more resistant to antibiotics

Endospores

copy genetic info and can withstand extreme conditions

Fimbriae

sticky hairlike appendages

Pili

longer than fimbriae and pull cells together to exchange DNA

Taxis

ability to move towards/away from stimuli

Chemotaxis

responding to chemical stimuli

Flagella

little tails allowing for movement, differ in structure