1Who first used the term "cell" after observing thin slices of cork?
Discovery of Cell
Easy
A.Anton van Leeuwenhoek
B.Robert Hooke
C.Matthias Schleiden
D.Theodor Schwann
Correct Answer: Robert Hooke
Explanation:
Robert Hooke observed small box-like spaces in cork and named them cells.
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2Which scientist was among the first to observe living microorganisms using a microscope?
Discovery of Cell
Easy
A.Robert Hooke
B.Robert Brown
C.Rudolf Virchow
D.Anton van Leeuwenhoek
Correct Answer: Anton van Leeuwenhoek
Explanation:
Anton van Leeuwenhoek used powerful simple microscopes to observe living microorganisms.
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3What is the basic structural and functional unit of life?
Basic Properties of Cell
Easy
A.The tissue
B.The cell
C.The organ
D.The organism
Correct Answer: The cell
Explanation:
All living organisms are made of cells, which perform essential life functions.
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4Which process allows cells to produce new cells?
Basic Properties of Cell
Easy
A.Cell staining
B.Cell fixation
C.Cell diffusion
D.Cell division
Correct Answer: Cell division
Explanation:
Cell division produces new cells for growth, repair, or reproduction.
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5Which structure controls the movement of many substances into and out of a cell?
Basic Properties of Cell
Easy
A.Nucleolus
B.Ribosome
C.Cell membrane
D.Cell wall
Correct Answer: Cell membrane
Explanation:
The cell membrane is selectively permeable and regulates movement of substances.
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6What does the unity of cells refer to?
Unity and diversity of Cells
Easy
A.Cells live in identical habitats
B.Cells have identical shapes
C.Cells are all the same size
D.Cells have common basic features
Correct Answer: Cells have common basic features
Explanation:
Cells share features such as genetic material, cytoplasm, and a cell membrane.
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7Why do cells have different shapes and structures?
Unity and diversity of Cells
Easy
A.They contain no genetic material
B.They lack cell membranes
C.They are all different species
D.They perform different functions
Correct Answer: They perform different functions
Explanation:
Cell shape and structure are often specialized to support a cell's particular function.
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8Which instrument is commonly used to observe cells?
Cell under the microscope
Easy
A.Barometer
B.Thermometer
C.Microscope
D.Centrifuge
Correct Answer: Microscope
Explanation:
A microscope magnifies objects that are too small to be seen clearly with the unaided eye.
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9What is magnification?
Cell under the microscope
Easy
A.Coloring of a specimen
B.Enlargement of an image
C.Drying of a specimen
D.Cutting of a specimen
Correct Answer: Enlargement of an image
Explanation:
Magnification makes an object appear larger than its actual size.
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10Which tool is often used to add color to cell structures for easier observation?
Cell under the microscope
Easy
A.Stain
B.Thermometer
C.Ruler
D.Lens cap
Correct Answer: Stain
Explanation:
Stains increase contrast and make particular cell structures easier to see.
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11Which type of cell lacks a membrane-bound nucleus?
Prokaryotic and eukaryotic cells
Easy
A.Eukaryotic cell
B.Plant cell
C.Animal cell
D.Prokaryotic cell
Correct Answer: Prokaryotic cell
Explanation:
Prokaryotic cells do not have a membrane-bound nucleus.
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12Which type of cell contains a membrane-bound nucleus?
Prokaryotic and eukaryotic cells
Easy
A.Viroid
B.Prokaryotic cell
C.Viral particle
D.Eukaryotic cell
Correct Answer: Eukaryotic cell
Explanation:
Eukaryotic cells contain a nucleus surrounded by a nuclear membrane.
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13Which organism is made of prokaryotic cells?
Prokaryotic and eukaryotic cells
Easy
A.Bacterium
B.Oak tree
C.Human
D.Mushroom
Correct Answer: Bacterium
Explanation:
Bacteria are prokaryotes and do not have membrane-bound nuclei.
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14Which structure is found in plant cells but not usually in animal cells?
Cell Architecture: Animal cell and plant cell
Easy
A.Cytoplasm
B.Cell membrane
C.Chloroplast
D.Ribosome
Correct Answer: Chloroplast
Explanation:
Chloroplasts are plant-cell organelles that carry out photosynthesis.
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15Which structure gives additional support and protection to plant cells?
Cell Architecture: Animal cell and plant cell
Easy
A.Cell wall
B.Nucleus
C.Golgi apparatus
D.Mitochondrion
Correct Answer: Cell wall
Explanation:
The plant cell wall provides strength and helps maintain cell shape.
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16Which organelle is commonly called the control center of a eukaryotic cell?
Cell Architecture: Animal cell and plant cell
Easy
A.Nucleus
B.Ribosome
C.Vacuole
D.Lysosome
Correct Answer: Nucleus
Explanation:
The nucleus contains most of the cell's genetic material and helps control cell activities.
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17Which cell component contains the cell's genetic material in most eukaryotic cells?
Cell Size and components
Easy
A.Nucleus
B.Cytoplasm
C.Cell wall
D.Vacuole
Correct Answer: Nucleus
Explanation:
In eukaryotic cells, most genetic material is contained inside the nucleus.
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18What is the jelly-like material that fills much of a cell called?
Cell Size and components
Easy
A.Cytoplasm
B.Capsid
C.Cellulose
D.Chromatin
Correct Answer: Cytoplasm
Explanation:
Cytoplasm fills the cell and contains organelles suspended in a fluid medium.
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19Why are viruses generally not considered cellular organisms?
Viruses and Viroids
Easy
A.They are always larger than cells
B.They contain too many organelles
C.They perform photosynthesis
D.They lack cellular structure
Correct Answer: They lack cellular structure
Explanation:
Viruses are acellular particles and do not have the complete structure of a cell.
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20What is a viroid?
Viruses and Viroids
Easy
A.A small infectious RNA molecule
B.A protein-only bacterium
C.A complete eukaryotic cell
D.A membrane-bound organelle
Correct Answer: A small infectious RNA molecule
Explanation:
Viroids are very small infectious agents made of short, circular RNA molecules without a protein coat.
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21A scientist observes repeated box-like compartments in a thin slice of cork. Which conclusion is most directly supported by this observation?
Discovery of Cell
Medium
A.Cork cells actively perform photosynthesis
B.Cork contains organized structural units
C.All living cells contain chloroplasts
D.Cells can survive without any internal contents
Correct Answer: Cork contains organized structural units
Explanation:
Hooke’s observation of cork revealed small compartments, which he called cells, although the cork cells were no longer living.
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22Why was Leeuwenhoek’s work important in the history of cell biology?
Discovery of Cell
Medium
A.He proved that cells arise only from nonliving matter
B.He observed living microorganisms with improved lenses
C.He established that all cells contain mitochondria
D.He discovered the cell nucleus in plant tissues
Correct Answer: He observed living microorganisms with improved lenses
Explanation:
Leeuwenhoek used powerful single-lens microscopes to observe living microorganisms, including bacteria and protists.
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23A cell is placed in an environment where nutrients are available, but its plasma membrane becomes unable to regulate transport. Which function would be most directly disrupted?
Basic Properties of Cell
Medium
A.Control of substances entering and leaving
B.Production of ribosomal subunits
C.Formation of chromosomes during division
D.Storage of hereditary information
Correct Answer: Control of substances entering and leaving
Explanation:
The plasma membrane is selectively permeable and regulates the movement of substances into and out of the cell.
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24A cell maintains a stable internal pH despite changes in its surroundings. This ability is an example of:
Basic Properties of Cell
Medium
A.Homeostasis
B.Evolution
C.Endocytosis
D.Differentiation
Correct Answer: Homeostasis
Explanation:
Homeostasis is the maintenance of relatively stable internal conditions despite external changes.
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25A mutation prevents a cell from producing proteins needed for energy metabolism. Which cellular property would be affected most immediately?
Basic Properties of Cell
Medium
A.Ability to maintain a rigid cell wall
B.Ability to obtain and use energy
C.Ability to transmit light through cytoplasm
D.Ability to increase its surface-to-volume ratio
Correct Answer: Ability to obtain and use energy
Explanation:
Proteins involved in metabolism help cells convert nutrients into usable energy, so energy processing would be impaired.
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26Muscle cells and nerve cells have different shapes and functions, yet both contain DNA and ribosomes. What does this best illustrate?
Unity and diversity of Cells
Medium
A.Different cell types must belong to different kingdoms
B.Cells share core features but can be specialized
C.Cell specialization eliminates all common structures
D.Only cells with identical shapes can contain DNA
Correct Answer: Cells share core features but can be specialized
Explanation:
Cells show unity through shared basic structures and processes, while diversity arises through specialization in structure and function.
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27Two organisms have cells with plasma membranes, ribosomes, and genetic material. One organism is unicellular, while the other is multicellular. Which conclusion is most appropriate?
Unity and diversity of Cells
Medium
A.Both organisms share fundamental cellular features
B.The multicellular organism must lack ribosomes
C.Their cells cannot have a common evolutionary history
D.The unicellular organism cannot carry out metabolism
Correct Answer: Both organisms share fundamental cellular features
Explanation:
All cells have several fundamental features, even though organisms differ in complexity and the degree of cellular specialization.
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28A student switches from a objective lens to a objective while using a ocular lens. What is the new total magnification?
Cell under the microscope
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
Total magnification equals ocular magnification multiplied by objective magnification: .
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29A specimen appears enlarged but blurry when viewed under a light microscope. Which adjustment would most directly improve sharpness without changing magnification?
Cell under the microscope
Medium
A.Adjust the fine-focus knob
B.Remove the coverslip from the slide
C.Replace the specimen with a thicker one
D.Increase the objective magnification immediately
Correct Answer: Adjust the fine-focus knob
Explanation:
The fine-focus knob makes small focusing adjustments that improve image sharpness after the specimen has been brought into approximate focus.
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30A stain is added to an unstained cheek-cell sample before microscopy. What is the primary purpose of the stain?
Cell under the microscope
Medium
A.To make the cells divide more rapidly
B.To reduce the microscope’s resolving power
C.To increase contrast between cell structures
D.To replace the cells’ missing organelles
Correct Answer: To increase contrast between cell structures
Explanation:
Many cell structures are nearly transparent, so stains increase contrast and make them easier to distinguish.
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31A newly discovered cell contains DNA in a nucleoid region but has no membrane-bound nucleus. How should it be classified?
Prokaryotic and eukaryotic cells
Medium
A.As a prokaryotic cell
B.As a eukaryotic cell
C.As a nonliving cell fragment
D.As a virus particle
Correct Answer: As a prokaryotic cell
Explanation:
Prokaryotic cells lack a membrane-bound nucleus; their DNA is located in a nucleoid region.
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32A drug blocks the function of the endoplasmic reticulum in a cell. The drug would affect eukaryotic cells more directly because they:
Prokaryotic and eukaryotic cells
Medium
A.Always have a cell wall
B.Lack genetic material in the cytoplasm
C.Use ribosomes only outside the cell
D.Contain membrane-bound organelles
Correct Answer: Contain membrane-bound organelles
Explanation:
The endoplasmic reticulum is a membrane-bound organelle found in eukaryotic cells and is absent from prokaryotic cells.
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33Which observation would provide the strongest evidence that a cell is eukaryotic?
Prokaryotic and eukaryotic cells
Medium
A.It contains a membrane-bound nucleus
B.It has a plasma membrane
C.It contains DNA as genetic material
D.It contains ribosomes in its cytoplasm
Correct Answer: It contains a membrane-bound nucleus
Explanation:
A membrane-bound nucleus is a defining feature of eukaryotic cells and is absent in prokaryotes.
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34A plant cell is placed in bright light and supplied with carbon dioxide. Which organelle is most directly involved in converting light energy into chemical energy?
Cell Architecture: Animal cell and plant cell
Medium
A.Centriole
B.Lysosome
C.Chloroplast
D.Golgi apparatus
Correct Answer: Chloroplast
Explanation:
Chloroplasts contain pigments and internal membranes that support photosynthesis, converting light energy into chemical energy.
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35A cell has a large central vacuole, a cellulose cell wall, and chloroplasts. Which type of cell is it most likely to be?
Cell Architecture: Animal cell and plant cell
Medium
A.A typical animal cell
B.A typical plant cell
C.A viral particle
D.A bacterial cell
Correct Answer: A typical plant cell
Explanation:
Large central vacuoles, cellulose cell walls, and chloroplasts are characteristic features of plant cells.
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36If lysosomes in an animal cell stop functioning, which process would be most directly impaired?
Cell Architecture: Animal cell and plant cell
Medium
A.Formation of the plant cell wall
B.Replication of bacterial chromosomes
C.Synthesis of glucose from sunlight
D.Breakdown of worn-out cell materials
Correct Answer: Breakdown of worn-out cell materials
Explanation:
Lysosomes contain digestive enzymes that break down cellular waste, damaged organelles, and some engulfed materials.
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37Why are most cells relatively small rather than extremely large?
Cell Size and components
Medium
A.Large cells always lack a plasma membrane
B.Small cells do not require energy for metabolism
C.Large cells cannot contain genetic material
D.Small cells have a favorable surface-area-to-volume ratio
Correct Answer: Small cells have a favorable surface-area-to-volume ratio
Explanation:
As a cell grows, its volume increases faster than its surface area, making exchange with the environment less efficient.
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38A cell’s volume increases substantially while its surface area increases only slightly. Which consequence is most likely?
Cell Size and components
Medium
A.Complete disappearance of the cytoplasm
B.Immediate loss of all hereditary information
C.Automatic conversion into a prokaryotic cell
D.Slower exchange of materials relative to cell demand
Correct Answer: Slower exchange of materials relative to cell demand
Explanation:
A lower surface-area-to-volume ratio reduces the membrane area available for exchanging materials relative to the cell’s internal needs.
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39A toxin damages ribosomes but leaves the plasma membrane intact. Which cellular activity would be affected first?
Cell Size and components
Medium
A.Storage of water in vacuoles
B.Diffusion of oxygen
C.Protein synthesis
D.Separation of chromosomes by spindle fibers
Correct Answer: Protein synthesis
Explanation:
Ribosomes assemble amino acids into proteins, so damaging them directly disrupts protein synthesis.
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40A virus can reproduce only after entering a host cell. What does this indicate about viruses?
Viruses and Viroids
Medium
A.They contain all organelles needed for protein synthesis
B.They depend on host-cell machinery for replication
C.They are complete cells with independent metabolism
D.They reproduce through ordinary cell division
Correct Answer: They depend on host-cell machinery for replication
Explanation:
Viruses lack the complete machinery needed for independent reproduction and use components of host cells to make new virus particles.
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41Why did Robert Hooke's observations of cork lead to the term "cell" without establishing that all living organisms are cellular?
Discovery of Cell
Hard
A.He examined bacteria before observing plant tissue
B.He used a microscope incapable of resolving membranes
C.He observed only empty compartments in dead tissue
D.He identified nuclei but not surrounding cytoplasm
Correct Answer: He observed only empty compartments in dead tissue
Explanation:
Cork consists of dead cells whose contents have disappeared, leaving box-like walls. Hooke named these compartments, but he did not observe living cellular organization.
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42Which observation most directly supported Schleiden and Schwann's cell theory while also exposing a limitation later corrected by Virchow?
B.Cells contain identical organelles in every organism
C.All cells arise spontaneously from nonliving material
D.Only plants are composed of repeating compartments
Correct Answer: Different tissues contain membrane-bound compartments
Explanation:
Schleiden and Schwann recognized plants and animals as cellular, but early formulations did not correctly emphasize that new cells arise from preexisting cells.
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43A synthetic compartment contains enzymes, genetic material, and a selectively permeable boundary but cannot maintain internal conditions or reproduce independently. Which conclusion is most appropriate?
Basic Properties of Cell
Hard
A.It is a virus because it contains genetic material
B.It is a eukaryote because it contains several enzymes
C.It is a prokaryote because it lacks membrane-bound organelles
D.It has some cellular features but is not a complete cell
Correct Answer: It has some cellular features but is not a complete cell
Explanation:
A cell must integrate metabolism, information storage, boundary control, and reproduction. Possessing individual components does not guarantee autonomous cellular life.
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44Why is compartmentalization especially important for a large metabolically active cell?
Basic Properties of Cell
Hard
A.It allows genetic material to remain outside all membranes
B.It eliminates the need for membrane transport proteins
C.It makes every reaction occur at the same pH
D.It creates localized conditions and shortens diffusion distances
Correct Answer: It creates localized conditions and shortens diffusion distances
Explanation:
Internal compartments concentrate reactants, maintain distinct chemical conditions, and reduce the distances over which molecules must travel.
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45A bacterium and a human cell both synthesize proteins using ribosomes. Which inference best illustrates cellular unity without ignoring cellular diversity?
Unity and diversity of Cells
Hard
A.Their protein synthesis reflects conserved ancestry despite different organization
B.Their ribosomes must have identical structures and sizes
C.Their metabolic pathways must be identical in every detail
D.Their genomes must be located inside membrane-bound nuclei
Correct Answer: Their protein synthesis reflects conserved ancestry despite different organization
Explanation:
Core processes such as translation are widely conserved, whereas ribosome structure, cellular compartments, and regulatory mechanisms can differ substantially.
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46Two cells have similar genomes but differ greatly in shape, metabolism, and function. Which mechanism most plausibly accounts for this difference?
Unity and diversity of Cells
Hard
A.Differential gene expression and environmental regulation
B.Replacement of DNA with unrelated hereditary molecules
C.Random loss of all genes unrelated to cell shape
D.Complete absence of ribosomes in the less active cell
Correct Answer: Differential gene expression and environmental regulation
Explanation:
Cell specialization commonly results from expressing different subsets of genes in response to developmental signals and environmental conditions.
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47A specimen appears blurred because structures outside the focal plane contribute light to the image. Which method would most directly improve optical sectioning?
Cell under the microscope
Hard
A.Bright-field microscopy with lower magnification
B.Confocal microscopy with focused illumination
C.Phase-contrast microscopy without optical sectioning
D.Electron microscopy using thicker sections
Correct Answer: Confocal microscopy with focused illumination
Explanation:
Confocal microscopy rejects much out-of-focus light and can generate optical sections through fluorescently labeled specimens.
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48A researcher wants to observe organelle ultrastructure at nanometer-scale resolution but must examine fixed, nonliving material. Which choice is most suitable?
Cell under the microscope
Hard
A.Scanning electron microscopy of a transparent monolayer
B.Transmission electron microscopy of thin sections
C.Light microscopy of an unstained living culture
D.Phase-contrast microscopy of a hydrated specimen
Correct Answer: Transmission electron microscopy of thin sections
Explanation:
Transmission electron microscopy provides high-resolution internal images from thin sections, but fixation and preparation prevent observation of living dynamics.
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49A fluorescent label is visible only when its target is abundant, even though the target is present throughout the cell. Which limitation most likely explains this result?
Cell under the microscope
Hard
A.Detection depends on signal above background noise
B.The microscope cannot detect molecules smaller than cells
C.Fluorescence always reveals only membrane proteins
D.Fluorescent probes convert all low-abundance targets to DNA
Correct Answer: Detection depends on signal above background noise
Explanation:
Microscopy detects a signal only when it is sufficiently strong relative to background, so low-abundance targets may remain undetectable.
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50A cell contains circular DNA, 70S ribosomes, and a plasma membrane but no nucleus. Which additional observation would most strongly distinguish it from a typical bacterium?
Prokaryotic and eukaryotic cells
Hard
A.A cell wall containing peptidoglycan
B.A chromosome associated with basic proteins
C.Ribosomes attached to messenger RNA
D.A membrane-bound compartment containing its genome
Correct Answer: A membrane-bound compartment containing its genome
Explanation:
A membrane-bound nuclear compartment is a defining eukaryotic feature. The other observations can occur in bacteria or are not decisive alone.
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51Why can a prokaryotic cell divide rapidly despite lacking the extensive internal membrane system of a eukaryotic cell?
Prokaryotic and eukaryotic cells
Hard
A.It lacks DNA replication and copies only its plasma membrane
B.Its smaller, less compartmentalized organization reduces replication overhead
C.Its ribosomes operate without messenger RNA or transfer RNA
D.It stores all metabolic enzymes outside the cell boundary
Correct Answer: Its smaller, less compartmentalized organization reduces replication overhead
Explanation:
Prokaryotes generally have fewer internal structures to duplicate and coordinate, although their division rate also depends on nutrients, temperature, and regulation.
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52An antibiotic inhibits bacterial ribosomes but has little immediate effect on cytosolic protein synthesis in a human cell. Which explanation is most defensible?
Prokaryotic and eukaryotic cells
Hard
A.Bacterial ribosomes are located inside human nuclei
B.Human cells synthesize proteins without ribosomes
C.Antibiotics cannot enter any eukaryotic cell
D.Bacterial and cytosolic eukaryotic ribosomes differ structurally
Correct Answer: Bacterial and cytosolic eukaryotic ribosomes differ structurally
Explanation:
Bacterial ribosomes are 70S, whereas cytosolic eukaryotic ribosomes are 80S. Structural differences can create selective drug effects.
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53A plant cell placed in a hypotonic solution does not normally burst, whereas an animal cell may lyse. Which structural difference best explains this outcome?
Cell Architecture: Animal cell and plant cell
Hard
A.The plant cell wall resists excessive expansion
B.Plant ribosomes prevent osmotic movement across membranes
C.Animal cells contain chloroplasts that absorb water
D.The plant nucleus actively pumps water outward
Correct Answer: The plant cell wall resists excessive expansion
Explanation:
Water enters both cells by osmosis, but the rigid plant cell wall generates resistance and turgor pressure that limits swelling.
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54A mutation prevents formation of functional plasmodesmata in a plant tissue. Which process would be most directly disrupted?
Cell Architecture: Animal cell and plant cell
Hard
A.Direct exchange of signals and solutes between adjacent cells
B.Synthesis of ATP within the mitochondrial matrix
C.Replication of DNA inside the plant cell nucleus
D.Assembly of cellulose within the extracellular wall
Correct Answer: Direct exchange of signals and solutes between adjacent cells
Explanation:
Plasmodesmata are cytoplasmic channels connecting neighboring plant cells and permit intercellular transport and communication.
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55A cell has chloroplasts, a large central vacuole, and cellulose walls but lacks mitochondria. Which prediction is most accurate?
Cell Architecture: Animal cell and plant cell
Hard
A.It must be an animal cell with unusually strong membranes
B.It cannot sustain normal cellular respiration and energy balance
C.It will compensate by converting chloroplasts into nuclei
D.It will function normally because chloroplasts replace all mitochondria
Correct Answer: It cannot sustain normal cellular respiration and energy balance
Explanation:
Chloroplasts perform photosynthesis, whereas mitochondria provide major respiratory ATP production. Photosynthesis does not fully replace mitochondrial functions.
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56If a spherical cell doubles its radius while retaining the same composition, how do its surface-area-to-volume ratio and diffusion challenge change?
Cell Size and components
Hard
A.The ratio halves, making exchange relatively less efficient
B.The ratio remains constant, so diffusion is unchanged
C.The ratio doubles, making exchange relatively more efficient
D.The ratio quadruples, making internal transport unnecessary
Correct Answer: The ratio halves, making exchange relatively less efficient
Explanation:
For a sphere, surface area scales as and volume as , so surface-area-to-volume ratio scales as . Doubling radius halves the ratio.
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57A cell's volume increases eightfold while its radius changes proportionally. Which change would occur if its shape remained spherical?
Cell Size and components
Hard
A.Its radius doubles and its surface area quadruples
B.Its radius quadruples and its surface area doubles
C.Its radius triples and its surface area increases eightfold
D.Its radius doubles and its surface area doubles
Correct Answer: Its radius doubles and its surface area quadruples
Explanation:
Because volume is proportional to , an eightfold volume increase requires a twofold radius increase. Surface area, proportional to , then increases fourfold.
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58Which cell design most effectively maintains rapid exchange with the environment while increasing total metabolic capacity?
B.A thickened cell boundary with no transport proteins
C.A large smooth sphere with minimal membrane area
D.A folded or elongated form with numerous internal membranes
Correct Answer: A folded or elongated form with numerous internal membranes
Explanation:
Folding and elongation increase effective exchange area, while internal membranes provide additional surfaces for metabolic reactions.
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59A pathogen contains a short circular RNA molecule, has no capsid, and replicates only within plant cells. Which classification best fits it?
Viruses and Viroids
Hard
A.Cellular plasmid with ribosomes
B.Bacteriophage
C.Viroid
D.Enveloped animal virus
Correct Answer: Viroid
Explanation:
Viroids are small, circular, infectious RNA molecules without protein coats, primarily known as plant pathogens.
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60Why is a virus generally excluded from definitions of autonomous cellular life even when it carries genetic information and evolves?
Viruses and Viroids
Hard
A.It lacks independent metabolism and depends on host machinery
B.It cannot contain nucleic acids or undergo genetic variation
C.It is always smaller than every known cellular organelle
D.It reproduces only through ordinary binary fission
Correct Answer: It lacks independent metabolism and depends on host machinery
Explanation:
Viruses contain genetic information and evolve, but they generally lack autonomous metabolism and replication machinery, requiring a host cell for reproduction.
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