Module 2: Basic components of living systems Flashcards
how do you calculate magnification?
magnification = size of image ÷ actual size
transmission electron microscope
- a beam of electrons is transmitted through a specimen and is focused to produce an image
- has the best resolution
scanning electron microscope
- a beam of electrons is sent across the surface of the specimen and the reflected electrons are collected
- resolution isn’t as good as transmission electron microscope
- can produce a 3D image
what are the advantages of a light microscope?
- inexpensive to buy/operate
- small and portable
- simple sample prep
- vacuum isn’t required
- specimens can be living or dead
what are the disadvantages of a light microscope?
- only x2000 magnification (lower than electron)
- lower resolution than electron microscope
what are the advantages of an electron microscope?
- x500000 magnification
- high resolution
- images can be digitally coloured
what are the disadvantages of an electron microscope?
- expensive to buy and operate
- large and needs to be installed
- complex sample prep
- sample prep often distorts material
- vacuum is required
- specimens are dead
what are the components of a eukaryotic animal cell?
- nucleus
- nuclear envelope
- nucleolus
- mitochondria
- cytoskeleton
- vesicles
- lysosomes
- centrioles
- golgi apparatus
- RER
- SER
- ribosomes
- flagella
- cilia
what are the components of a eukaryotic plant cell?
- vacuole
- cellulose cell wall
- chloroplasts- nucleus
- nuclear envelope
- nucleolus
- mitochondria
- cytoskeleton
- vesicles
- lysosomes
- centrioles
- golgi apparatus
- RER
- SER
- ribosomes
- flagella
- cilia
what are the components of a prokaryotic cell?
- plasmid DNA
- ribosomes
- cell wall
- flagella
what are the differences between eukaryotic and prokaryotic cells?
- prokaryotic cells don’t have a nucleus
- prokaryotes have circular DNA
- prokaryotes only have non membrane-bound organelles
- ribosomes are smaller in prokaryotes
what is the cell wall made from in prokaryotes?
peptidoglycan
what is the cell wall made from in fungi?
chitin
what is the cell wall made from in plants?
cellulose
what is a nucleus?
it contains the DNA, meaning it controls the metabolic activities of the cell
