Microscopes/Cell Ultrastructure (Biology 008) Flashcards
What is magnification
How much larger something is compared to it’s real size
What is resolution
A measure of how clear an image is
What is contrast
The difference between light and dark areas of an image
What are two things that a microscope does to an image
What is seen through the microscope is that the image is upside down, back to front
How big is the magnification of a light microscope
It is 1000 times the actual size of the specimen
What is limited when the magnification is greater
The resolution of the image becomes limited
Can living cells be seen through a light microscope
Yes
Why is the electron microscope better than the light microscope
Better magnification and resolution
What kind of cells can be seen through an electron microscope
Organelles, membrane-enclosed cells can be seen through an electron microscope
What are the two roles of the nucleus
Directs cell activity, contains RNA and DNA
What is the role of the nucleolus
Produce ribosomal RNA , RNA transcription occurs here
What is the two roles of the nuclear envelope
Controlled passage of genetic information into the cytoplasm, have an inner and outer membrane that surrounds the nucleus
What is the role of nuclear pores
Semi-permeable in a sense, able to control entry and exit of proteins, RNAs and large complexes of macromolecules
What are the roles in the cell membrane
The cell membrane is semi-permeable, has proteins in that membrane itself to allow large molecules and ions to enter and leave the cell, the membrane is protected by a cell wall made out of cellulose in which provides support
