| A | B |
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| Identify Robert Hooke. | He was an Englishman who examined cork under a microscope; he coined the term "cells" in 1665. |
| Identify Anton van Leeuwenhoek. | He used a single-lens microscope to observe pond water and other things. He was surprised at all the living organisms he saw. |
| Identify Matthias Schleiden. | He was a German botanist who in 1838 concluded that all plants were made of cells. |
| Identify Theodor Schwann. | In 1839, he concluded that all animals are made of cells. |
| Identify Rudolph Virchow. | He proposed the idea that all cells come from existing cells. |
| What does the cell theory say? | 1) all living things are composed of cells; 2) cells are the basic units of structure & function in living things; 3) new cells are produced from existing cells. |
| What is the advantage of confocal light microscopy? | This scans cells with a laser beam, so 3-dimensional images of cells and their parts can be produced. |
| How do scientists follow molecules as they move through cells? | They use fluorescent labels and light microscopy to do this. |
| What advantage do electron microscopes have? | They reveal details up to 1000 times smaller than those visible in a light microscope. This occurs because electron wavelengths are much shorter than those of light. |
| What is a TEM? | It's a transmission electron microscope. Cells & tissues examined under it must be cut into ultrathin slices, and then cell structures and large protein molecules can be studied. |
| What is an SEM? | It's a scanning electron microscope; a pencillike beam of electrons is scanned over the specimen's surface, producing 3-dimensional images of cells. |
| What is the big disadvantage of electron microscopes? | Only nonliving, preserved cells and tissues can be examined by them. (pg. 171) |
| What type of microscope made it possible to study surfaces and observe single atoms? | Scanning proble microscopes made this possible. (see 172) |
| What 2 characteristics do all cells have in common? | 1) They are surrounded by a cell membrance that serves as a barrier; 2) at some point, they contain DNA. |
| What two characteristics do all cells have in common? | 1) Eukaryotes which have a nucleus; 2) prokaryotes which do not have a nucleus. |
| Give one example of a prokaryote. | Bacteria are prokaryotes. They carry on all activities associated with living things. (173) |
| Give examples of eukaryotes, remembering that they have nuclei? | Plants, animals, fungi, protists are all examples. |
| List the differences between prokaryotes and eukaryotes. | 1) Prokaryotes are smaller and simpler; 2) eukaryotes have a nucleus & prokaryotes don't; 3) eukaryotes are more complex, having dozens of structures and internal membranes. |
