B1 - Cell Structure and Transport Flashcards
What is the defining feature of a eukaryotic cell?
They all have a nucleus
What type of organism are prokaryotic?
Bacteria
Name the two types of DNA in prokaryotic cells
Plasmid and chromosomal
What is the function of ribosomes?
Protein synthesis
What is the function of plasmid DNA?
It allows bacteria to swap genetic information between them
What is the equation for finding the size of a real object?
Size of image/magnification
Define resolution.
The measure of the level of detail you can see with a microscope
Why are electron microscopes better than light microscopes?
They have a higher magnification and resolution
When does diffusion occur?
Oxygen transported into the bloodstream, carbon dioxide out of bloodstream, waste product urea from cells into bloodstream, etc.
What can affect the rate of diffusion?
Steepness of concentration gradient, temperature, surface area of the membrane
Define osmosis
Movement of water from an area of low concentration (dilute) to an area of high concentration (concentrated) through a semi-permeable membrane
What makes active transport unique?
It requires energy because it is going against the concentration gradient
Give the features for an effective exchange surface
Large surface area and a thin wall/membrane (constant blood supply in animals)
How is gas exchange made effective in the lungs?
Millions of alveoli leads to a very large total surface area, short diffusion pathway, a good blood supply, air supply due to ventilation
Describe how root hair cells are adapted to their function
They have long projections which increase the surface area and shorten the diffusion pathway, as well as no chloroplasts due to being underground so more space is made
