Cell structure and microscopy Flashcards
How big are animal cells?
Animal cells are between 0.01mm and 0.05mm.
How big are plant cells?
Plant cells are between 0.01mm and 0.1mm.
What is the smallest size a human eye can see?
0.05mm
What is another word for eyepiece lens?
Another word for an eyepiece lens is an ocular.
What is an objective lens?
The objective lens is the one closest to the specimen, has a very short focal length, and produces a greatly magnified image.
What is a compound microscope?
A compound microscope is one with two lenses, the objective lens, and the eyepiece lens.
What is the focal length?
The focal length is the distance from the centre of the lens to the focal point.
What is the lens used in a microscope called?
The lens in a microscope is called convex.
What is the eyepiece lens?
The eyepiece lens is the one at the top of a compound microscope. Larger focal length than the objective lens. Magnifies image produced by the objective lens.
What is meant by magnification?
Magnification is the amount that something has been scaled up when viewed in a microscope.
What is the most common magnification of an eyepiece?
The most common magnification of an eyepiece is x10.
What is the formula for finding the magnification of a microscope?
Magnification objective lens x magnification eyepiece lens.
What is the formula for working out the magnification of an image?
Size of image / real size of image.
What is the division of a nanometer as a fraction and standard form?
1/000,000,000 metre.
1x 10-9
What is the division of a micrometer as a fraction and standard form?
1/1,000,000 metre
1x 10-6
What is a micrograph?
A micrograph is a photo taken of a microscopic image.
When is the coarse focus knob used?
The coarse focussed knob is used at low magnification.
When is the fine focus knob used?
The fine focus knob is used at high magnification.
Can the mitochondria be seen under a light microscope?
It can be seen but not in very good detail.
What is the function of the nucleus?
The nucleus control’s cell’s activity and contains the genetic information.
What is the function of the cytoplasm?
The cytoplasm is a jelly-like substance where most chemical reactions take place. Contains dissolved nutrients and salts.
What is the function of the cell membrane?
The cell membrane controls substances coming in and out of the cell. It is permeable for some but not all substances.
What is the function of the cell wall in plants?
The cell wall is made of cellulose and it strengthens the cell and supports the plant.
What is the function of the chloroplast?
Chloroplast contains a green pigment called chlorophyll which absorbs sunlight to make glucose. Contains enzymes needed for photosynthesis.
What is the function of the permanent vacuole?
Filled with cell sap to support the plant and keep it turgid.
What is a prokaryotic cell?
A cell without a nucleus - DNA moves within the cytoplasm.
What is a eukaryotic cell?
A cell that has a nucleus.
What is a specialized cell?
A cell that has become differentiated to carry out a particular function.
What does myelin do in a nerve cell?
Myelin insulates the axon which speeds up electrical impulses.
What are synapses?
Synapses are junctions that allow impulses to be transmitted from one neuron to another.
What does a condenser do in a light microscope?
A condenser converts the scattered light source into a converging beam.
