Questions and Answers
What do eukaryotic cells have that prokaryotes lack?
A nucleus and other internal organelles.
What groups make up prokaryotes?
Bacteria and Archaea.
At a molecular level, the members of the two domains of prokaryotes—the archaea and bacteria—differ as much from each other as either does from the eukaryotes.
True
Cells fall under which two categories?
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One thing all cells have in common is an ability to colonize any environment on Earth.
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Like the differentiated cells in an individual plant or animal, all bacteria have the same DNA.
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What structure would present a safe target for a new antibiotic?
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An organism that can survive life in a hydrothermal vent at the bottom of the ocean can thrive anywhere.
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The DNA in the nucleus of eukaryotic cells is separated from the cytoplasm by the:
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What statements about mitochondria are true?
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What statements about chloroplasts are true?
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Which organelle is an irregular maze of interconnected spaces enclosed by a membrane and functions as the site where most cell membrane components, as well as materials destined for export from the cell, are made?
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Which organelle is a stack of flattened membrane-enclosed sacs, functioning in receiving and often chemically modifying the molecules made in the endoplasmic reticulum?
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Which organelle is a small, irregularly shaped organelle in which intracellular digestion occurs?
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What mediates the exchange of materials between the endoplasmic reticulum, Golgi apparatus, the lysosomes, and the outside of the cell?
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What is the name of the process by which eukaryotic cells engulf material captured from an external medium?
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The largest single compartment in most cells is:
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What makes up the cytoskeleton?
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What roles are performed by the cytoskeleton?
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In plant cells, a tough cell wall takes the place of a cytoskeleton.
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The cytoskeleton is one of the few permanent fixtures in the cell.
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What organelle's ancestor was likely engulfed by primitive eukaryotes to help the cell survive in an oxygen-rich atmosphere?
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Mitochondria are essentially the same in all eukaryotes, including plants, animals, and fungi.From this observation, it can be concluded that mitochondria were most likely acquired:
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What is evidence for the endosymbiotic origins of mitochondria and chloroplasts?
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Study Notes
Cell Types and Structures
- Eukaryotic cells possess a nucleus and internal organelles, which prokaryotic cells lack.
- Prokaryotes are divided into two groups: Bacteria and Archaea.
- Archaea and Bacteria differ significantly at the molecular level, similar to how each differs from eukaryotes.
Cellular Characteristics
- All cells categorize into Prokaryotic and Eukaryotic types.
- Not all cells can colonize every environment; many thrive in specific conditions, like particular bacteria adapted to the human gut.
- Bacterial species have independent evolutionary paths and distinct DNA sequences, unlike specialized cells in multicellular organisms that share DNA.
Antibiotics and Cell Features
- Antibiotics target bacterial features unique to them, like the cell wall, sparing eukaryotic cells.
- Organisms adapted to extreme conditions (e.g., hydrothermal vents) cannot thrive in typical environments.
Genetic Structures
- The nuclear envelope separates eukaryotic DNA from the cytoplasm.
- Mitochondria and chloroplasts are believed to have originated from bacteria, contain their own DNA, and generate energy or food for the cell, respectively.
Organelles and Their Functions
- The Endoplasmic Reticulum (ER) is a maze of interconnected membranes where cell membrane components are synthesized.
- The Golgi Apparatus modifies and directs molecules from the ER to various cell locations or outside the cell.
- Lysosomes are small organelles responsible for intracellular digestion.
Material Exchange and Processes
- Transport vesicles facilitate material exchange between the ER, Golgi apparatus, lysosomes, and the cell exterior.
- Endocytosis is the process by which eukaryotic cells engulf external materials.
Cytoplasm and Cytoskeleton
- The largest compartment in cells is the cytosol.
- The cytoskeleton consists of actin filaments, intermediate filaments, and microtubules, aiding in cell shape, movement, and transporting materials.
- Plant cells also rely on cytoskeletal filaments alongside the cell wall for organelle transport and organization.
Persistence of Structures
- The cytoskeleton is dynamic rather than a permanent fixture in cells.
- Mitochondria likely descended from engulfed ancestors that helped eukaryotic cells survive in oxygen-rich environments, acquired before the divergence of cell types.
Endosymbiotic Theory
- Mitochondria and chloroplasts support endosymbiotic origins due to their double membranes, own DNA, ability to reproduce by division, and resemblance to bacteria.
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Description
Test your knowledge on the fundamental differences between prokaryotic and eukaryotic cells with this quiz. Explore key characteristics such as the presence of nuclei and organelles, as well as the groups that define prokaryotes. Perfect for biology students looking to reinforce their understanding of cellular biology concepts.
