End Show Slide 1 of 31 Copyright Pearson Prentice Hall 7-1 Life Is Cellular

End Show 7-1 Life Is Cellular Slide 2 of 31 Copyright Pearson Prentice Hall The Discovery of the Cell Early Microscopes In 1665, Robert Hooke used an early compound microscope to look at a thin slice of cork, a plant material. Cork looked like thousands of tiny, empty chambers. Hooke called these chambers “cells.” Cells are the basic units of life.

End Show 7-1 Life Is Cellular Slide 3 of 31 Copyright Pearson Prentice Hall The Discovery of the Cell Hooke’s Drawing of Cork Cells

End Show 7-1 Life Is Cellular Slide 4 of 31 Copyright Pearson Prentice Hall The Discovery of the Cell Scientists and their thoughts….. In 1838, Matthias Schleiden concluded that all plants were made of cells. In 1839, Theodor Schwann stated that all animals were made of cells. In 1855, Rudolph Virchow concluded that new cells were created only from division of existing cells. These discoveries led to the cell theory.

End Show 7-1 Life Is Cellular Slide 5 of 31 Copyright Pearson Prentice Hall The Discovery of the Cell The cell theory (CAN) states: 1. Cells are the basic units of structure and function in living things. 2. All living things are composed of cells. 3. New cells are produced from existing cells.

End Show 7-1 Life Is Cellular Slide 6 of 31 How can we look at cells? Copyright Pearson Prentice Hall

End Show 7-1 Life Is Cellular Slide 7 of 31 Copyright Pearson Prentice Hall Exploring the Cell Remember hearing about the Electron Microscopes? Reveal details 1000 times smaller than those visible in light microscopes. Electron microscopy can be used to visualize only nonliving, preserved cells and tissues.

End Show 7-1 Life Is Cellular Slide 8 of 31 Exploring the Cell Transmission electron microscopes (TEMs) Used to study cell structures and large protein molecules Specimens must be cut into ultra-thin slices Copyright Pearson Prentice Hall

End Show 7-1 Life Is Cellular Slide 9 of 31 Exploring the Cell Scanning electron microscopes (SEMs) Produce 3D images of cells Copyright Pearson Prentice Hall

End Show 7-1 Life Is Cellular Slide 10 of 31 Prokaryotes and Eukaryotes Cells are classified into two categories, depending on whether they contain a nucleus. The nucleus is a large membrane-enclosed structure that contains the cell's genetic material in the form of DNA. The nucleus controls many of the cell's activities. Copyright Pearson Prentice Hall

End Show 7-1 Life Is Cellular Slide 11 of 31 Prokaryotes and Eukaryotes Eukaryotes are cells that contain nuclei. Prokaryotes are cells that do not con tain nuclei. Copyright Pearson Prentice Hall

End Show 7-1 Life Is Cellular Slide 12 of 31 Copyright Pearson Prentice Hall Prokaryotes and Eukaryotes What are the characteristics of prokaryotes and eukaryotes? Get out your Venn Diagram

End Show 7-1 Life Is Cellular Slide 13 of 31 Copyright Pearson Prentice Hall Prokaryotes and Eukaryotes Prokaryotes Prokaryotes genetic material is not contained in a nucleus. Do not have membrane bound organelles. Smaller and simpler than eukaryotic cells. Examples include: Bacteria and blue-green algae.

End Show 7-1 Life Is Cellular Slide 14 of 31 Copyright Pearson Prentice Hall Prokaryotes and Eukaryotes Eukaryotes Eukaryotic cells contain a nucleus in which their genetic material is separated from the rest of the cell.

End Show 7-1 Life Is Cellular Slide 15 of 31 Copyright Pearson Prentice Hall Prokaryotes and Eukaryotes Larger and more complex than prokaryotic cells. Contain dozens of structures and internal membranes (organelles). Highly specialized. Plants, animals, fungi, and protists (unicellular organisms) are eukaryotes.

End Show 7-1 Life Is Cellular Slide 16 of 31 Similarities of Pro vs. Euk Both contain DNA Both are filled with cytoplasm and contain ribosomes Both have a plasma membrane. Copyright Pearson Prentice Hall

End Show 7-1 Life Is Cellular Slide 17 of The cell theory states that new cells are produced from nonliving material. existing cells. cytoplasm. animals. Copyright Pearson Prentice Hall

End Show 7-1 Life Is Cellular Slide 18 of The person who first used the term cell was Matthias Schleiden. Lynn Margulis. Anton van Leeuwenhoek. Robert Hooke. Copyright Pearson Prentice Hall

End Show 7-1 Life Is Cellular Slide 19 of Which organism listed is a prokaryote? protist bacterium fungus plant Copyright Pearson Prentice Hall

End Show 7-1 Life Is Cellular Slide 20 of One way prokaryotes differ from eukaryotes is that they contain DNA, which carries biological information. have a surrounding barrier called a cell membrane. do not have a membrane separating DNA from the rest of the cell. are usually larger and more complex. Copyright Pearson Prentice Hall