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Questions and Answers
What distinguishes viruses from living cells?
What distinguishes viruses from living cells?
How do viruses replicate?
How do viruses replicate?
Which statement about viroids is accurate?
Which statement about viroids is accurate?
What is a prion?
What is a prion?
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Why are viruses considered non-living?
Why are viruses considered non-living?
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Which characteristic is NOT true for viruses?
Which characteristic is NOT true for viruses?
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What type of virus specifically infects bacteria?
What type of virus specifically infects bacteria?
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How do algae differ from viruses?
How do algae differ from viruses?
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What is the fundamental unit of any living organism?
What is the fundamental unit of any living organism?
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Which type of microbe is classified as acellular?
Which type of microbe is classified as acellular?
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What distinguishes eukaryotes from prokaryotes?
What distinguishes eukaryotes from prokaryotes?
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What is the primary function of the cell membrane?
What is the primary function of the cell membrane?
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Which of the following is an example of cellular microbe?
Which of the following is an example of cellular microbe?
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What does selective permeability of the cell membrane refer to?
What does selective permeability of the cell membrane refer to?
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Viruses can be described as relying on what for reproduction?
Viruses can be described as relying on what for reproduction?
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Cytology is the study of what?
Cytology is the study of what?
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What is the primary function of the nucleus?
What is the primary function of the nucleus?
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Which component of the nucleus serves as its protective covering?
Which component of the nucleus serves as its protective covering?
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What is the semifluid portion of the cytoplasm known as?
What is the semifluid portion of the cytoplasm known as?
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What gives rough endoplasmic reticulum its distinctive appearance?
What gives rough endoplasmic reticulum its distinctive appearance?
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What is the main role of ribosomes within a cell?
What is the main role of ribosomes within a cell?
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Which organelle is known as the packaging plant of the cell?
Which organelle is known as the packaging plant of the cell?
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What type of protoplasm is cytoplasm classified as?
What type of protoplasm is cytoplasm classified as?
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What connects the Golgi Complex to the endoplasmic reticulum?
What connects the Golgi Complex to the endoplasmic reticulum?
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What is the primary role of flagella in flagellated cells?
What is the primary role of flagella in flagellated cells?
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Which of the following statements about prokaryotic cells is true?
Which of the following statements about prokaryotic cells is true?
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What is peptidoglycan primarily associated with in bacteria?
What is peptidoglycan primarily associated with in bacteria?
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What is the main function of the cytoplasm in prokaryotic cells?
What is the main function of the cytoplasm in prokaryotic cells?
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Which statement describes the action of crystal violet in the gram staining procedure?
Which statement describes the action of crystal violet in the gram staining procedure?
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How do cilia differ from flagella in structure?
How do cilia differ from flagella in structure?
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What type of reproduction do prokaryotic cells primarily employ?
What type of reproduction do prokaryotic cells primarily employ?
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What does structural staining help observe in bacteria?
What does structural staining help observe in bacteria?
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What is microbial intoxication?
What is microbial intoxication?
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What characterizes peptidoglycan in Gram-negative bacteria?
What characterizes peptidoglycan in Gram-negative bacteria?
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What serves as the control center in prokaryotic cells?
What serves as the control center in prokaryotic cells?
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Which organelle is known as the energy factory in eukaryotic cells?
Which organelle is known as the energy factory in eukaryotic cells?
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Microbes that have the potential to cause disease under certain conditions are referred to as what?
Microbes that have the potential to cause disease under certain conditions are referred to as what?
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What is a test used to determine the presence of bacterial enzymes?
What is a test used to determine the presence of bacterial enzymes?
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Which method is useful in identifying eukaryotes?
Which method is useful in identifying eukaryotes?
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What is the primary characteristic of Gram-negative bacteria concerning their cell wall structure?
What is the primary characteristic of Gram-negative bacteria concerning their cell wall structure?
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Study Notes
Algae
- Photosynthetic eukaryotes
- Wide variety of shapes
- Both sexual and asexual reproduction forms
- Can be unicellular or multicellular
Viruses
- Possess either DNA or RNA, unlike living cells, which possess both
- Unable to replicate on their own, replication depends on the viral nucleic acid once inserted into a host cell
- Unlike cells, they do not divide by binary fission, mitosis, or meiosis
- Lack genes and enzymes needed for energy production
- They require the ribosomes, enzymes, and metabolites of the host cell for protein and nucleic acid production
- Bacteriophages are a type of virus that specifically infect bacteria
- Viroids are nucleic acid without a protein coating
- Prions are infectious proteinacious particles without nucleic acids, associated with various neurologic diseases
Cell Structure and Function
- The fundamental unit of any living organism
- Exhibits the basic characteristics of life
- Obtains nutrients from the environment to produce energy for metabolism and other life processes
- There are two major categories of microbes: accellular microbes and cellular microbes
- Acellular microbes include viroids and viruses
- Cellular microbes include prokaryotes and eukaryotes
- Viruses appear to be a result of regressive evolution
- They are composed of just a few genes protected by a protein coat, and may contain one or a few enzymes
- Viruses depend on the energy and metabolic machinery of a host cell to reproduce
- Viruses are classified in a separate category, as they are acellular and do not have cells
- Cytology is the study of the structure and function of cells
Eukaryotic Cell Structure
- Have a true nucleus, meaning that their DNA is enclosed by a nuclear membrane
- Cell Membrane: Encloses and holds the cell together.
- Cell Membrane Also known as the plasma, cytoplasmic, or cellular membrane
- Cell Membrane: Is like the skin around the cell, separating the cell's contents from the outside world
- Cell Membrane: Regulates the passage of nutrients, waste products, and secretions into and out of the cell
- Cell Membrane: Is also selectively permeable, meaning only certain substances can enter and leave the cell.
- Nucleus: Controls the functions of the entire cell, and can be thought of as the cell's "command center".
- Nucleus: Contains linear DNA molecules and proteins
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Nucleus: Composed of:
- Nucleoplasm: The material matrix or base material of the nucleus
- Chromosomes: Embedded in the nucleoplasm
- Nuclear Membrane: Serves as the skin around the nucleus, and contains holes through which large molecules can enter and exit the nucleus
- Cytoplasm:: A type of protoplasm.
- Cytoplasm: Is a semifluid, gelatinous, nutrient matrix.
- Cytoplasm: The location where most of the cell's metabolic reactions occur
- Cytoplasm: The semifluid portion of the cytoplasm, excluding the granules and organelles, is sometimes referred to as the cytosol
- Endoplasmic Reticulum (ER): A highly convoluted set of membranes interconnected and arranged to form a transport network of tubules and flattened sacs within the cytoplasm.
- Rough Endoplasmic Reticulum (RER): Has a rough appearance due to the many ribosomes attached to the outer surface of the membranes.
- Smooth Endoplasmic Reticulum: ER where ribosomes are not attached
- Ribosomes: Eukaryotic ribosomes range in diameter from 18 to 22 nm.
- Ribosomes: Primarily composed of RNA
- Ribosomes: The sites of protein synthesis within a cell
- Golgi Complex: Also known as the Golgi apparatus or Golgi body.
- Golgi Complex: Connects or communicates with the ER.
- Golgi Complex: A stack of flattened, membranous sacs that completes the transformation of newly synthesized proteins into mature, functional proteins.
- Golgi Complex: Packages proteins into small membrane-enclosed vesicles for storage within the cell
- Golgi Complex: Is also referred to as the "packaging plant"
- Flagella: Used for locomotion in certain cells.
- Flagella: Enable flagellated cells to swim through liquid environments.
- Flagella: Are referred to as organelles of locomotion.
- Cilia: Are also organelles of locomotion, but they are shorter, thinner, and more numerous than flagella
Prokaryotic Cell Structure
- Prokaryotic cells: About 10 times smaller than eukaryotic cells.
- Reproduction of prokaryotic cells: Binary fission, a simple division of one cell into two cells.
- All bacteria are prokaryotes, as are the archaea.
- Cell Membrane: Also known as the plasma, cytoplasmic, or cellular membrane.
- Cell Membrane Encloses the cytoplasm of a prokaryotic cell.
- Cytoplasm: Semiliquid, composed of water, enzymes, dissolved oxygen (in some bacteria), waste products, essential nutrients, proteins, carbohydrates, and lipids.
- Cytoplasm: A complex mixture of all the materials required by the cell for its metabolic functions.
- Bacterial Cell Wall: The main constituent of most bacterial cell walls is a complex macromolecular polymer called peptidoglycan, also known as murein.
- Peptidoglycan: Found only in bacteria.
Gram Staining
- A staining procedure used to classify bacteria
- Most bacteria are colorless, transparent, and difficult to observe.
- Various staining methods have been devised to enable scientists to examine bacteria
- Specific stains and staining techniques are used to observe bacterial cell morphology
- A simple stain is sufficient to determine bacterial shape and morphologic arrangement
- Structural staining procedures are used to observe bacterial capsules, spores, and flagella
- Primary Stain: The application of crystal violet
- Mordant: The application of iodine to intensify the color of the stain
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Description
Test your knowledge on the classifications of algae, viruses, and cell structure and function. This quiz covers the basic characteristics and reproduction mechanisms in these biological entities. Perfect for students studying biology and life sciences.