Cells‼️ Flashcards
What are differences between a light microscope and an electron microscope?
light microscopes: inexpensive,low maintenance,lower magnification,lower resolution,image is coloured,live and dead specimens can be seen
electron: expensive,high maintenance,high magnification,high resolution,image is black and white, only dead and dried specimens can be seen.
What is the formula used to calculate the magnification of an image?
magnification= image size/actual size
A specimen is 50 μm wide in real life. Calculate the width of the image under a magnification of x100.Give your answer in mm.
5000 μm or 5mm
What colour is the lowest powered objective lens?
Red
What colour is the medium powered objective lens?
yellow
What colour is the highest powered objective lens?
Blue
What does MRS GREN stand for?
Movement,Respiration,Senses,Growth,Reproduction,Excretion,Nutrition
What is the cytoplasm?
Where most chemical reactions take place
What is the nucleus?
controls the activities of the cell and contains chromosomes made of coiled DNA molecules. The chromosomes are normally found in pairs.
What does the cell membrane do?
controls what comes in and out of the cell
What do ribosomes do?
They are the site of protein synthesis
What does the mitochondria do?
aerobic respiration
What does the cell wall do?
Gives the cell strength, it is made of cellulose
What does the vacuole do?
It contains sap and help support the shape of the cell
What does the chloroplast do?
contains chlorophyll which is needed for photosynthesis
What sub cellular structures are present ONLY in plant cells?
Cell wall,vacuole and chloroplast
What are eukaryotes?
Cells which are complex and made of many cells Eg: Animal and Plant cells.They have a nucleus where the DNA is found and other membrane bound organelles.
What are prokaryotes?
Cells which are much smaller and simpler than eukaryotes and are a single celled organism Eg: bacteria. DNA is not found in a nucleus and is circular
What are the differences between eukaryotic and prokaryotic cells?
Prokaryotic cells are much smaller than eukaryotes, prokaryotes have no membrane bound organelles,DNA is not in a nucleus in prokaryotes,prokaryotes have extra rings of plasma
What are archaea?
Microorganisms which are similar to bacteria in size and simplicity of structure but radically different in molecular organization.
What are extremophiles?
A microorganism, especially an archaean, that lives in conditions of extreme temperature, acidity, alkalinity, or chemical concentration.
What is magnification?
The ability of a lens or other optical instrument to enlarge the size of the optical image
What is the magnification of the low power objective lens?
x4
What is the magnification of the medium powered objective lens?
x10