Flashcards in Topic 1.2 - Cell Biology Deck (24)
What are prokaryotic cells?
Prokaryotes are organisms whose cells lack a nucleus ('pro' = before ; 'karyon' = nucleus)
What kingdom do prokaryotic cells belong to?
Monera and have been further classified into two distinct domains
What 2 domains are prokaryotic cells classified as?
- Archaebacteria – found in extreme environments like high temperatures, salt concentrations or pH (i.e. extremophiles)
- Eubacteria – traditional bacteria including most known pathogenic forms (e.g. E. coli, S. aureus, etc.)
9 main features in prokaryotic cells:
What is binary fission?
A form of asexual reproduction used by prokaryotic cells
Process of binary fission:
- The circular DNA is copied in response to a replication signal
- The two DNA loops attach to the membrane
- The membrane elongates and pinches off (cytokinesis), forming two cells
How do prokaryotic cells divide?
Through binary fission
What are eukaryotic cells?
Organisms whose cells contain a nucleus (‘eu’ = good / true ; ‘karyon’ = nucleus)
Which has a more complex structure, prokaryote or eukaryote?
Where were eukaryotic cells believed to evolve from?
From prokaryotic cells (via endosymbiosis)
What are Eukaryotic cells are compartmentalized by?
Membrane-bound structures (organelles) that perform specific roles
Eukaryotes can be divided into four distinct kingdoms:
3 universal organelles:
9 Eukaryotic Organelles:
3 organelles only in plant cells:
Organelle only found in plant cells:
6 Key features of a prokaryotic cell:
6 Key features in an animal cell:
4 Key features of a plant cell:
All bacteria share features common to every prokaryotic cell, what are they?
- They lack a nucleus and membrane-bound organelles
- They have circular DNA that is naked (not bound to protein)
- They have smaller ribosomes (70S)
Different types of bacteria can be distinguished according to a number of characteristics, what are they?
Cell wall composition
Prokaryotic cells and eukaryotic cells differ in a number of key features, including:
- DNA (composition and structure)
- Organelles (types present and relative sizes)
- Reproduction (mode differs according to chromosome structure)
- Average size (exceptions may exist)
DNA in prokaryotes and eukaryotes:
P: DNA is naked. DNA is circular. Usually no introns
E: DNA bound to protein. DNA is linear. Usually has introns.