Questions and Answers
What is the basic unit of all forms of life?
Cell
What do all cells contain?
DNA
What is the fundamental concept of biology that states that all living things are composed of cells?
Cell theory
The cell theory states that all living things are composed of ______.
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Cells are the basic units of structure and function in ______ things.
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New cells are produced from existing ______.
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What is the thin, flexible barrier that surrounds all cells, regulating what enters and leaves the cell?
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What is another name for the cell membrane?
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What structure contains the cell's genetic material in the form of DNA?
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What type of organism has cells that contain a nucleus?
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What are the functions of eukaryotes?
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Give examples of eukaryotes.
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What are the two types of eukaryote cells?
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Eukaryote cells are ______ than prokaryote cells.
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What is a unicellular organism that lacks a nucleus called?
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What are the functions of prokaryotes?
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Prokaryote cells are ______ than eukaryote cells.
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Give an example of a prokaryotic organism.
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What type of microscope uses beams of light or electrons to produce magnified images?
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What are the two types of microscopes?
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The two types of lenses in a compound microscope are ______ and ______.
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How many times do light microscopes magnify up to?
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What type of microscope uses beams of electrons focused by magnetic fields?
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Electron microscopes examine what?
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What are the two types of electron microscopes?
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What does a transmission electron microscope explore?
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What does a scanning electron microscope do?
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What is a photo of an object seen through a microscope called?
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The cells of multicellular organisms cannot survive ______.
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Who was the first to discover cells in 1665?
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Who first discovered microorganisms by observing pond water in 1665?
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Who concluded that all plants are made of living cells in 1838?
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Who stated in 1839 that all animals are made of cells?
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Who published the idea that new cells can be produced only from the division of existing cells in 1855?
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Study Notes
Cell Basics
- Cells are the basic unit of all forms of life, comprising the fundamental structure and function in living organisms.
- All living things contain DNA, which carries genetic information.
Cell Theory
- A key concept in biology:
- All living things are made of cells.
- Cells are the fundamental units of structure and function.
- New cells arise from existing cells.
Cell Structure
- The cell membrane, also known as the plasma membrane, is a thin, flexible barrier that surrounds cells and manages entry and exit of substances.
- The nucleus houses the cell's genetic material in the form of DNA, crucial for cell regulation and function.
Eukaryotes vs. Prokaryotes
- Eukaryotes are organisms with cells that contain a nucleus, including plants, animals, fungi, and protists, and are generally larger and more complex.
- Prokaryotes are unicellular organisms that lack a nucleus, example: bacteria; they are smaller and simpler than eukaryotic cells.
- Eukaryotic cells function to support, communicate, move, and produce proteins or other products, whereas prokaryotic cells grow, reproduce, and react to environmental stimuli.
Microscopy
- Microscopes enhance visibility of specimens, using light or electrons to produce magnified images.
- Two main types of microscopes are compound and electron microscopes.
- Light microscopes typically magnify up to 1000 times, while electron microscopes, using electron beams, can explore nonliving cells and tissues in greater detail.
- Electron microscopes come in two varieties:
- Transmission electron microscopes (TEM) produce two-dimensional images and help explore cell structure.
- Scanning electron microscopes (SEM) create three-dimensional images by scanning the specimen's surface.
Historical Contributions
- Robert Hooke (1665) was the first to discover cells by observing cork.
- Anton van Leeuwenhoek (1665) discovered microorganisms through pond water observations.
- Matthias Schleiden (1838) noted that all plants are made of living cells.
- Theodor Schwann (1839) confirmed that all animals are composed of cells.
- Rudolf Virchow (1855) proposed that new cells are formed solely through the division of existing cells.
Multicellular Organisms
- Cells in multicellular organisms cannot survive independently; they rely on one another to function effectively.
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Description
Dive into the essentials of life with these flashcards based on Biology Chapter 8. Learn about the basic unit of life, cell theory, and the role of DNA in cells. Perfect for reviewing key concepts in cellular biology.
