Questions and Answers
Which of the following structures is known as the control center of the cell?
Prokaryotic cells typically have a larger size compared to eukaryotic cells.
False
What is the primary function of mitochondria in the cell?
To produce energy (ATP)
The cell membrane is composed of a __________ bilayer.
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Match the following cell types with their examples:
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Which of the following is a characteristic of all living organisms?
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Eukaryotic cells have a nucleus, while prokaryotic cells do not.
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What are the two types of structurally different cells?
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The basic part of a eukaryotic cell that regulates what enters and leaves is the ______.
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Match the following cellular structures with their functions:
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Which characteristic of life explains the ability to react to environmental changes?
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Prokaryotic cells include plants, animals, and fungi.
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What is the term for the process by which living things give rise to offspring?
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Who introduced the term 'protoplasm' to describe the living substance within the cell?
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All organisms consist of cells, and new cells can only be created from existing cells.
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Name the scientist who is credited with the discovery of the cell.
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The basic unit of organization of all organisms is the __________.
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Match the scientists to their discoveries:
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Which characteristic of life describes the ability of an organism to maintain stable internal conditions?
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Living organisms do not need to respond to stimuli to be classified as alive.
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What is the term used for energy usage in living organisms?
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Study Notes
Development of Cell Theory
- Lorenz Oken proposed that all organisms originate from and consist of cells in 1805.
- Felix Dujardin discovered "sarcode," a living substance within cells, in 1835.
- Jan Evangelista Purkinje replaced the term "sarcode" with "protoplasm."
- Principles of Cell Theory:
- Cells are the basic unit of organization in all organisms.
- All organisms are composed of one or more cells.
- New cells arise from preexisting cells.
- Anton Van Leuwenhoek discovered "animalcules" in dental plaque and pond water.
- Robert Hooke is credited with the discovery of cells.
- Robert Brown identified the nucleus.
- Matthias Schleiden confirmed that all plants are composed of cells.
Characteristics of Life
- Living things are made up of cells, forming the fundamental structure of life.
- All living organisms utilize energy for growth, maintenance, and activity.
- Growth and development occur throughout the life cycle of living organisms.
- Homeostasis is the ability to regulate internal conditions to maintain stability.
- Living organisms respond to environmental stimuli, adapting to changes.
- Evolution is the process by which living organisms adapt over generations.
- Reproduction is the biological process by which organisms produce offspring.
Types of Cells
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Prokaryotic Cells:
- Lack a nucleus; DNA is located in a nucleoid region.
- Examples: Bacteria and blue-green algae.
- Cell parts:
- Capsule: Protects the cell.
- Pilus: Hair-like structures for attachment.
- Flagellum: Whip-like structure for movement.
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Eukaryotic Cells:
- Contain a true nucleus with genetic material enclosed in a nuclear membrane.
- Examples: Plants, animals, fungi, algae, and protists.
- Basic parts include:
- Plasma membrane: The outermost layer, acting as a gatekeeper.
- Cytoplasm: Gel-like substance where organelles are suspended.
- Nucleus: Control center containing DNA.
Differences Between Eukaryotic and Prokaryotic Cells
- Eukaryotes are typically multicellular; prokaryotes are generally unicellular.
- Eukaryotes include animals and plants, while prokaryotes encompass bacteria and archaea.
- Genetic recombination in eukaryotes occurs through meiosis; prokaryotic recombination is usually unidirectional.
- Ribosomes in eukaryotes are larger compared to those in prokaryotes.
Major Cell Organelles
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Cell Membrane:
- Outermost structure; protects the cell and regulates material exchange.
- Composed of a phospholipid bilayer.
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Cytoplasm:
- Contains organelles; primarily composed of water, proteins, and salts; contains a gel-like solution known as cytosol.
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Nucleus:
- Acts as the control center of the cell; contains DNA; surrounded by a double membrane and usually single per cell.
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Mitochondria:
- Known as the "powerhouse of the cell"; produces ATP, the energy currency of the cell, by converting chemical energy from food.
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Description
Explore the key figures and milestones in the development of cell theory. Learn about Lorenz Oken, Felix Dujardin, and Jan Evangelista Purkinje, and their contributions to our understanding of cells and protoplasm. This quiz will test your knowledge of these significant historical figures and concepts.
