Chapter 3 The Cell Flashcards
(15 cards)
What are the three main tenets of cell theory?
- All organisms are made up of cells 2. Cells are the basic unit of life 3. All cells come from pre-existing cells
Who coined the term ‘cell’?
Robert Hooke
What evidence supports the endosymbiotic theory?
Mitochondria and chloroplasts have circular DNA, 70S ribosomes, and replicate via binary fission
What does germ theory state?
Microorganisms are the cause of many diseases
What type of symbiotic relationship benefits one organism without affecting the other?
Commensalism
Name two differences between prokaryotic and eukaryotic cells.
Prokaryotes lack a nucleus and membrane-bound organelles; eukaryotes have both.
Which group of prokaryotes includes many human pathogens and is gram-negative?
Proteobacteria
What are two traits that distinguish Archaea from Bacteria?
Archaea have ether-linked lipids and lack peptidoglycan in their cell walls.
How does a gram-positive bacterium differ from a gram-negative one?
Gram-positive has thick peptidoglycan and no outer membrane; gram-negative has thin peptidoglycan and an outer LPS membrane.
What structure allows bacterial motility?
Flagella
Why is Mycoplasma pneumoniae resistant to penicillin?
It lacks a cell wall, so penicillin has no target.
What did Semmelweis demonstrate?
Handwashing significantly reduces postpartum infections.
Which scientist first traced cholera to a contaminated water source?
John Snow
What kind of ribosomes are found in mitochondria?
70S ribosomes
What does Pasteur’s swan-neck flask experiment demonstrate?
Microorganisms come from the environment, not spontaneous generation.
