2. PLANT VS ANIMAL CELLSDescribe the differences between plant and animal cells

Identify organelles under the electron microscope

Microscopes

Light microscope – useful magnification up to 1500x – any higher magnification gives blurred images. Can distinguish between objects as small as 200nm.

Electron microscopes – 1930’s – uses a beam of electrons and give resolutions of about 0.2 nm (1000x better than the light microscope) and magnifications of up to 500 000x

Why do we not use electron microscopes at school?

How they work.

Electron microscopes…

2 types –1. Transmission electron microscopes send

electrons through a very thin sample and can see inside cells. We use these to study cell organelles.

2. Scanning electron microscope sends electrons onto the surface of a sample where they bounce off and are detected by a screen. These are useful for making 3D images of the outside of organelles or cells.

Which microscope? TEM, SEM or light?

Plant vs Animal Cells – complete the table

Cell Plant Animal

Cell Membrane

Cell Wall

Nucleus

Endoplasmic Reticulum

Mitochondria

Chloroplasts

Golgi Body

Lysosomes

Centrioles

Vacuoles

Can you identify any organelles in this electron microscope pictures?

Plant or animal cell?

What is the difference between these two? Which is from a plant cell?

Close up of part of an adrenal cell. What do you think the dark shapes are?

Summary:

Plant and animal cells can be viewed best using the ___________________ microscope as this can mangnify up to ________________ and distinguish between objects ____________ nm in size.

Plant cells are different from animal cells because they contain ______________, _____________ and a __________________. They are generally ___________ in size than animal cells.