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69 Cards in this Set
- Front
- Back
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Description and function of the nucleus
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-Description: The nucleus is the largest organelle in eukaryotes (10-20nm) surround by a double membrane (the nuclear envelope).
-Function: It contains the chromosomes(chromatin material). Certain cells lack a nucleus: mammalian mature red blood cells, sieve tube elements of the phloem cell, and cylindrical fibers of voluntary muscle. |
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Description and function of the nucleolus
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-Description: The round, dark-staining body in the nucleus.
-Function: It synthesizes ribosomes. |
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Description and function of the nuclear envelope
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-Description: Double membrane with pores (100 nm). Outer membrane continuous with the ER.
-Function: Quick movement of rRNA, ATP, proteins, hormones between the nucleus and cytoplasm. |
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Description and function of the plasma membrane (surface membrane)
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-Description: Lipid bilayer double membrane less than 10nm thick.
-Function: A barrier between the cytoplasm and its environment- retains the cytosol. |
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Description and function of the mitochondria include small circular DNA
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-Description: Rod or cylindrical shape; double membrane: smooth inner and outer member. Inner membrane has folds called cristae. The inside is the matrix (0.5-1.5 nm wide and 3.0-10.0nm wide)
-Function: Site of aerobic respiration and synthesis of ATP |
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Description and function of the centriole
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-Description: Nine paired microtubules arranged in short, hollow cylinders; two at right angles outside the nucleus.
-Function: Help chromosomes move during division; grow the spindle fibers. |
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Description and function of the microtubules
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-Description: Straight, hollow cylinders (25nm wide) made up of tubulin.
-Function: Shape and support the cell, help move cell parts in the cytoplasm, guide and direct organelles. |
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Description and function of the lysosomes
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-Description: Spherical vesicles with a membrane produced by the Golgi bodies or the ER.
-Function: They have digestive (hydrolytic) enzymes to break down food and damaged organelles as part of the defense system. |
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Description and function of the golgi body (golgi apparatus, golgi coimplex)
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-Description: Stacks of flat membraneous sacs.
-Function: Found in metabolically active cells. They synthesize biochemicals, hormones, and glycoproteins and package into vesicles. May also form lysosomes. |
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Description and function of the ribosome include 80s in cytoplasm and 70s in chloroplast and mitochondria
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-Description: 25nm in diameter, have 2 subunits(70s and 80s), no membranes. Made up of RNA and protein. Found free in the cytoplasm or on the surface of the ER.
-Function: Site of protein synthesis. |
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Description and function of the rough endoplasmic reticulum
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-Description: Network of folded membranes that buds off the outer membrane of the nuclear envelope. Vesicles are formed with a single membrane. Ribosomes are attached.
-Function: Site of protein synthesis. The tiny sacs store and transport substances that are packaged in vesicles that fuse with the Golgi complex. |
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Description and function of the rough endoplasmic reticulum
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-Description: Network of folded membranes that buds off the outer membrane of the nuclear envelope. Vesicles are formed with a single membrane. No ribosomes are attached.
-Function: Lipid and steroid synthesis (estrogen, testosterone), calcium storage in muscle fibers. |
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Description and function of the cytoplasm
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-Description: Fluid surrounding the organelles. Cytosol-the aqueous part.
-Function: Suspension of organelles; where chemical reactions take place. |
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Description and function of the chloroplasts including small circular DNA
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-Description: Double-membraned, inner member folds and branches forming lamellae or thylakoids. Thylakoids arranged as flat circular piles called grana.
-Function: Chlorophylls and other pigments responsible for photosynthesis. Chloroplasts contain 70s ribosomes and circular DNA. |
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Description and function of the plasmodesmata
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-Description: Formed when a cell divides and makes new cell walls between the separating cell contents.
-Function: Connect the cytoplasm and adjacent cells. |
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Description and function of the large vacuole and tonoplast in plant cells
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-Description: Large fluid filled sac surrounded by the tonoplast membrane.
-Function: Contains cell sap for the plant cell. |
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Description and function of gap junction.
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Description: Gap junctions are highly specialized membrane structures that contain clusters of channels. This organization requires the membranes of two neighboring cells to come close to each other leaving a 2-4 nm gap
Function: Cellular communication is important for the maintenance of tissue/organ homeostasis in multicellular organisms. Using this communication, cells can review differences in environmental conditions and respond accordingly. This concept could involve either sending a signal to neighboring cells to generate a coordinated response or isolating groups of cells from the rest of the community to maintain tissue integrity. |
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Description and function of peroxisomes.
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Description: Membrane-bound organelle occurring in the cytoplasm of eukaryotic cells..
Function: Peroxisomes contain enzymes that oxidize certain molecules normally found in the cell, notably fatty acids and amino acids. These oxidation reactions produce hydrogen peroxide, which is the basis of the name peroxisome. In plant cells, peroxisomes play a variety of roles including converting fatty acids to sugar and assisting chloroplasts in photorespiration. In animal cells, peroxisomes protect the cell from its own production of toxic hydrogen peroxide. |
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What organelles are specific to prokaryotic cells?
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70s ribosomes, circular DNA in cytoplasm, flagella made of flagellin
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What organelles are specific to eukaryotic cells?
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80s ribsomes, nucleus, mitochondria, chloroplasts, golgi apparatus, smooth ER, rough ER, cilia and flagella made of tubulin, peroxisomes(involved in metabolic reactions), lysosomes(common in animals), centrioles(all animals and some lower plant forms)
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What organelles do eukaryotic and prokaryotic cells have in common?
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Cell wall (in plants, not animals), ribosomes, plasma membrane, flagella, chromosomes, cytoplasm(made of cytosol, a semifluid substance)
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Which of the following cell structures can you see under a light microscope?
a. mitochondrion b. ribosome c. rough ER d. smooth ER |
a. mitochondrion
The mitochondrion is the second largest structure in the cell, next to the nucleus. |
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The use of electrons as a source of radiation in the electron microscope allows high resolution to be achieved because electrons:
a. are negatively charged b. can be focused using electromagnets c. have a very short wavelength d. travel at the speed of light |
c. have a very short wavelength
The higher the frequency and lower the wavelength, the more energy and resolution. Light microscopes have a longer wavelength and lower frequency than electron microscopes. |
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Which of the following structures is found in animal cells, but not in plant cells?
a. cell surface membrane b. centriole c. chloroplast d. golgi body |
b. centriole
This is used for dividing the nucleus and growing spindle fibers for mitosis/meiosis. |
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List ten structures you could find in an electron micrograph of an animal cell which would be absent from the cell of a bacterium.
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Golgi bodies, smooth ER, rough ER, nucleus, mitochondria, centrioles, lysosomes, nucleolus, cytoskeleton, and 80s ribosomes. (There can be something other than those listed like centrosomes, microvilli, and vacuoles.)
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What structure in the animal cell is similar to the plasmodesmata?
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Gap junction
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The difference between magnification and resolution.
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Magnification is the size of the image compared to the actual object. Resolution is how much you can distinguish between two things that are close together and how detailed an image is.
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The difference between the light microscope and electron microscopes.
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Light microscopes focus light, can view living specimens, uses colored dyes on the specimens, and can magnifiy up to 1,000x without losing resolution. Electron microscopes focus electrons, can view dead/non-living specimens, uses heavy metals on the specimens (as stains), and can magnify up to 10,000,000x without losing resolution.
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The difference between nucleus and nucleolus.
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The mucleus and the mucleolus are both organelles that have DNA. The nucleus is the control center of the cell, larger (largest organelle in eukaryotic cells), and bound by a double membrane (the nuclear envelope). The nucleolus contains genes specifically for making ribosomes, synthesizes ribosomes, is located inside the nucleus, and does not have a membrane.
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The difference between chromatin and chromosomes.
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Chromatin and chromosomes are structures that contain DNA. Chromatin is an uncoiled DNA double helix covered in histones. can be seen during interphase, and specializes in metabolic and other activities. Chromosomes are compact forms of nucleic acid and protein, can be seen during metaphase, and distributes genetic info to daughter cells.
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The difference between membrane and envelope.
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The membrane and envelope are both structures that cover/surround a structure. A membrane is a thin, permeable layer found in all cells. An envelope is made of two membranes and can be found in eukaryotic cells.
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The difference between smooth ER and rough ER.
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The smooth ER and rough ER are systems of folded membranes that transport molecules. The smooth ER produces lipids and steroids and stores calcium in muscle fiber. The rough ER has ribosomes attached to it and synthesizes proteins that are transported through the smooth ER to the golgi apparatus.
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The difference between prokaryotes and eukaryotes?
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There are two main types of cells: prokaryotes and eukaryotes. Both have DNA, cytoplasm, plasma membrane, and ribosomes. Prokaryotes are simple cells that are relatively small (<5 nm) and unicellular. They have circular DNA that do not have histones or specialized proteins around it, peptidoglycan cell walls, 70s ribosomes, flagellum made of flagellin, and a huge variety of metabolic activites. They reproduce asexually through binary fission. Eukaryotes are large cells (>10 nm) and are often multicellular. They always have a nucleus, membrane-bound organelles, linear, protein-associated DNA, 80s ribsomes, cytoskeleton, and flexible waving cilia or flagellae made of tubulin. They reproduce sexually or asexually through mitosis or meiosis. They have commonj metabolic pathways.
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Three organelles each lacking a boundary membrane.
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Centrosomes, centrioles, nucleolus, ribosomes, cytoskeleton, and flagella.
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Three organelles each bounded by a single membrane.
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Lysosomes, ER, golgi bodies, and vacuole.
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Three organelles each bounded by two membranes.
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Nucleus, mitochondria, and chloroplasts.
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What cell structure/organelle manufactures lysosomes?
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Golgi apparatus
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What cell structure/organelle manufactures ribosomes?
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Nucleolus
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What cell structure/organelle is the site of protein synthesis?
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Ribosomes
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What cell structure/organelle can bud off vesicles which form the Golgi body?
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ER
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What cell structure/organelle can transport newly synthesized protein round the cell?
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Vesicles (ER->golgi->cell surface)
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What cell structure/organelle manufactures ATP in the animal and plant cell?
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Mitochondria
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What cell structure/organelle controls the activity of the cell because it contains the DNA?
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Nucleus
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What cell structure/organelle carries out photosynthesis?
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Chloroplasts
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What cell structure/organelle can act as a starting point for the growth of spindle microtubules during cell division?
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Centrioles
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What cell structure/organelle contains chromatin?
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Nucleus
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What cell structure/organelle is a partially permeable barrier only about 7 nm thick?
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Membrane
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What cell structure/organelle is about 25 nm in diameter?
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Ribosomes
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The mitochondria in pancreatic cells are mostly sausage-shaped in three dimensions. Explain why some of the mitochondria in the EM appear roughly circular.
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The mitochondria will appear circular if they are cut, in transverse section/across (the long axis).
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Describe the process of protein secretion/exporting. (It involves the rough ER, golgi apparatus, secretory vesicles, and the cell membrane.)
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The ribsomes attached to the rough ER produce proteins. Those proteins made from the ribosomes are moved into and through the rough ER. The rough ER buds off small vesicles. Those vesicles fuse to form the Golgi apparatus; (therefore) protein moves into Golgi apparatus; the protein may be modified/processed inside Golgi apparatus; Golgi apparatus buds off Golgi vesicles;Golgi vesicles travel to cell surface membrane; Golgi vesicle(s) fuses with cell surface membrane; protein/enzyme leaves cell; exocytosis/secretion;
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What is used to measure organisms under a light microscope? How is it used?
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Organisms may be measured using an eyepiece graticule and a stage micrometer. The eyepiece graticule shows the observed size, and the stage micrometer gives the actual size.
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What formula is used to measure the actual size of an organism through a light microscope?
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A=I/M; A: Actual size, I: Observed size, M: Magnification.
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Which type of membrane would be present in the largest quantity in a prokaryotic cell?
A cell surface membrane B mitochondrial cristae C nuclear envelope D smooth endoplasmic reticulum |
A
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Which type of cell would contain the greatest relative numbers of mitochondria?
A bacterial cell B mesophyll cell C muscle cell D parenchyma cell |
C
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In a cell that is specialised for secreting protein, which of the following would be present in relatively large amounts?
A cell surface membrane B Golgi vesicles C lysosomes D smooth endoplasmic reticulum |
B
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Which structure could be described as a microtubule-organising centre?
A centriole B Golgi apparatus C nucleus D spindle |
A
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What are microtubules made of?
A cellulose B DNA C lipid D protein |
D
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Which structure could be found in a plant cell but not in a prokaryotic cell?
A 20 nm ribosomes B cell surface membrane C circular DNA D thylakoid |
D
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Which organelle makes lysosomes?
A Golgi apparatus B nucleus C ribosome D smooth endoplasmic reticulum |
A
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A protein that is to be secreted from a cell would pass through a sequence of cell organelles in the following order:
A Golgi apparatus → rough endoplasmic reticulum → secretory vesicle B Golgi apparatus → secretory vesicle → rough endoplasmic reticulum C rough endoplasmic reticulum → Golgi apparatus → secretory vesicle D secretory vesicle → Golgi apparatus → rough endoplasmic reticulum |
C
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A scientist calibrating an eyepiece graticule would notice what change when switching from a low-power lens to a high-power lens?
A The eyepiece units would appear closer together. B The eyepiece units would appear further apart. C The stage micrometer units would appear closer together. D The stage micrometer units would appear further apart. |
D
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What explains the fact that an increase in the voltage used in a transmission electron microscope results in an increase in the resolution obtained?
A The electromagnetic lenses function more efficiently. B Increasing the voltage increases the magnification. C The electron beam can penetrate the specimen more easily. D The wavelength of the electrons is shortened. |
D
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What is the role of ATP?
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-Muscle contraction
-Active transport -Synthesis of macromolecules -Stimulates the breakdown of substrates to make even more ATP for other uses. **ATP is energy currency not energy storage (glucose, glycogen, starch, fats) |
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What is the structure of viruses?
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They are not cellular structures. They consist of a core of nucleic acid (DNA or RNA) surrounded by a protein coat, called a capsid. Their size range consists of 20- 400 nm. (Only visible under electron microscope.)
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How do viruses reproduce?
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They can only reproduce in specific living cells and function as endoparasites in their host.
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How are they transported?
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They have to be transported in some way, like skin-to-skin contact or in the air, because they cannot move much on their own.
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Can viruses choose any host?
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They are particular with their host species.
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How are viruses classified?
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They are classified by the type of nucleic acid they have.
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Some viruses have an additional external envelope made of ______.
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Lipids and proteins
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