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Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
THINK ABOUT IT What’s the smallest part of any living thing that still counts as being “alive?”
Can we just keep dividing living things into smaller and smaller parts, or is there a point at which what’s left is no longer alive?
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
Early Microscopes
Mid-1600s scientists began using compound microscopes to observe living things.
In 1665, Robert Hooke used a microscope to look at cork- nonliving plant material
Cork looked like tiny, empty chambers
Hooke called the cork “cells”
cells are not empty chambers, but working parts, each with its own function.
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
This is what Hooke saw. The cork reminded him of monastery cells-places where monks
stay (chambers)
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
Early Microscopes
Anton van Leeuwenhoek examined pond water & sample taken from a human mouth.
He drew the organisms he saw in the mouth-bacteria.
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
The Cell Theory
cells are the basic units of life
1838, German botanist Matthias Schleiden stated-plants made of cells.
1839, German biologist Theodor Schwann stated-animals made of cells.
1855, German physician Rudolf Virchow concluded that new cells could be produced only from other cells,
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
The Cell Theory
summarized in the cell theory, a fundamental concept of biology.
The cell theory states:
-All living things are made up of cells.
-Cells are the basic units of structure and function in living things.
-New cells are produced from existing cells.
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
The Discovery of the Cell
What is the cell theory?
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
The Discovery of the Cell
What is the cell theory?
The cell theory states:
- All living things are made up of cells.
- Cells are the basic units of structure and function in living things.
- New cells are produced from existing cells.
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
Exploring the Cell
How do microscopes work?
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
Exploring the Cell
How do microscopes work?
Most microscopes use lenses to magnify the image of an object by focusing light or electrons.
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
Prokaryotes and Eukaryotes
Cells fall into two broad categories, depending on whether they contain a nucleus.
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.
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
Prokaryotes and Eukaryotes
Eukaryotes are cells that enclose their DNA in nuclei.
Prokaryotes are cells that do not enclose DNA in nuclei.
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
Prokaryotic cells-smaller & simpler
prokaryotes grow, reproduce, & respond to the environment, and some can even move by gliding along surfaces or swimming through liquids.
bacteria =prokaryotes.
Prokaryotes
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
Eukaryotes
Eukaryotic cells are larger & more complex
contain a lot of structures & internal membranes.
highly specialized.
eukaryotes: plants, animals, fungi, and “protists.”
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
Prokaryotes and Eukaryotes
cells range from 5 to 50 micrometers in diameter, the smallest bacteria are only 0.2 micrometers across.
the giant amoeba Chaos chaos may be 1000 micrometers in diameter,
all cells contain the molecule that carries biological information—DNA.
All cells are surrounded by a thin, flexible barrier -cell membrane.
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
Prokaryotes and Eukaryotes
How are prokaryotic and eukaryotic cells different?
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
Prokaryotes and Eukaryotes
How are prokaryotic and eukaryotic cells different?
Prokaryotic cells do not separate their genetic material within a nucleus. PRO-NO
In eukaryotic cells, the nucleus separates the genetic material from the rest of the cell. EU-DO!!!
Lesson OverviewLesson Overview Life Is CellularLife Is Cellular
You will be taking a quiz. Tell me if the following organisms are Prokaryotic or Eukaryotic…
Remember Pro=No Nucleus
(DNA is free floating in cytoplasm
Eu=Do
(DNA enclosed in nucleus)
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