Introduction to Cells Topic 2: Investigating Cells Standard Grade Biology Magnification Cells can be seen more clearly using microscopes magnify Microscopes _________________________ the cells Microscopes may have two.
Download ReportTranscript Introduction to Cells Topic 2: Investigating Cells Standard Grade Biology Magnification Cells can be seen more clearly using microscopes magnify Microscopes _________________________ the cells Microscopes may have two.
Introduction to Cells Topic 2: Investigating Cells Standard Grade Biology Magnification Cells can be seen more clearly using microscopes magnify Microscopes _________________________ the cells Microscopes may have two or objective lenses three__________________________________________ and one eyepiece lens ___________________________________________. Calculating Magnification To work out Total Magnification use the following formula TOTAL MAGNIFICATION = magnification of eyepiece lens x magnification of objective lens Since microscopes magnify cells we have a new unit of measurement. These new units are called microns _________________________. 1mm 1 1000 = = 1000 µm 1 µm Measuring Cell Size We can use microscopes to estimate the size of cells we are looking at e.g. if we know the diameter of the field of our field of view we can then estimate the size of the cells a)if the field of view = 1mm Field of view Onion cell then onion cells are 1mm (1000 µm) 0.5 ______________ mm 500 microns or ______________(µm) in length b)if the field of view = 0.5mm or 500µm then these cheek cells would be 500 5 100 µm in length mm or ______________ 0.5 mm (500 µm) Human cheek cell Magnification mm Field of View Microns (µm) X40 4 4000 X150 1 1000 X400 0.5 500 Staining Cells Animal and plant cells can be stained _________________________ so that the structures within cells ____________________________________ seen more clearly can be______________________________ _________________________ stains the Iodine nucleus _________________________ of onion cells and also its cell wall _________________________. Methyl Blue _________________________ is used to stain the nucleus _________________________ of human cheek cells __________________________. Acetic orcein _________________________ is used to chromosomes stain the _________________________ present in the nucleus of cells which are about to divide. This powerpoint was kindly donated to www.worldofteaching.com http://www.worldofteaching.com is home to over a thousand powerpoints submitted by teachers. This is a completely free site and requires no registration. Please visit and I hope it will help in your teaching.