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WorksheetsCell Structure, Organelles, and Membrane Transport
Total questions: 150
Worksheet time: 1hrs 15mins
Which feature best distinguishes prokaryotic cells from eukaryotic cells?
Presence of ribosomes
True nucleus enclosed by a membrane
Ability to perform cellular respiration
Presence of a cell membrane
In prokaryotic cells, where is circular DNA located?
Nucleolus
Nucleoid
Golgi apparatus
Mitochondrion
Which organelle is correctly matched with its primary function?
Golgi apparatus — protein synthesis
Rough ER — lipid detoxification
Mitochondria — ATP production via cellular respiration
Lysosomes — photosynthesis
Ribosomes are found in which locations in a eukaryotic cell?
Only in the nucleolus
Free in cytoplasm and bound to the Rough ER
Only on the Smooth ER
Embedded in the cell wall
Which set lists structures specific to plant cells as described?
Lysosomes, centrosomes, cilia
Chloroplasts, cell wall (cellulose), central vacuole
Mitochondria, ribosomes, Rough ER
Golgi apparatus, nucleolus, microtubules
According to the Fluid Mosaic Model, the cell membrane is best described as a:
Rigid protein layer with embedded lipids
Flexible bilayer of phospholipids with embedded or attached proteins, cholesterol, and carbohydrates
Single layer of phospholipids with carbohydrate tails
Permeable cellulose sheet with protein pores
Which statement about phospholipids in cellular membranes is accurate?
They have two hydrophilic tails and a hydrophobic head
They form a bilayer that is selectively permeable
They function only as transport channels
They are absent from prokaryotic membranes
Membrane proteins can serve all of the following roles EXCEPT:
Channels and carriers for transport
Receptors for signaling
Enzymes
Sites of DNA replication
Which transport process requires ATP to move substances against their concentration gradient?
Simple diffusion
Osmosis
Facilitated diffusion
Protein pumps (active transport)
Facilitated diffusion differs from simple diffusion because facilitated diffusion:
Moves substances from low to high concentration
Requires ATP
Uses specific channel or carrier proteins for larger or charged molecules
Moves only water across the membrane
Which statement best describes bulk transport endocytosis?
A vesicle fuses with the membrane to release substances out
The membrane folds inward to bring substances into the cell
Ions are pumped across the membrane by ATP-driven proteins
Small nonpolar molecules move down their gradient
Which phase of the cell cycle includes DNA replication converting a single chromatid into a chromosome with two sister chromatids?
G1 phase
S phase
G2 phase
M phase
What is the correct order of mitotic stages given their hallmark events?
Metaphase — Prophase — Telophase — Anaphase
Prophase — Metaphase — Anaphase — Telophase
Anaphase — Telophase — Prophase — Metaphase
Prophase — Anaphase — Metaphase — Telophase
Mitosis results in the production of:
Two genetically identical diploid daughter cells
Two genetically unique diploid daughter cells
Four genetically identical haploid daughter cells
Four genetically unique diploid daughter cells
During Meiosis I, what key event occurs?
Separation of sister chromatids
Separation of homologous chromosomes
DNA replication
Formation of two identical nuclei
Which phase of the cell cycle is the longest and includes growth and preparation for division?
Prophase
Interphase
Metaphase
M Phase (Mitosis)
During which subphase of interphase does DNA replication occur, converting a single chromatid into a chromosome with two sister chromatids?
G1 (Gap 1)
S (Synthesis)
G2 (Gap 2)
M Phase
What is the correct order of mitosis stages described for nuclear division producing two genetically identical diploid daughter cells?
Metaphase → Prophase → Anaphase → Telophase
Prophase → Metaphase → Anaphase → Telophase
Prophase → Anaphase → Metaphase → Telophase
Metaphase → Anaphase → Telophase → Prophase
Which event defines metaphase of mitosis?
Chromosomes condense and nuclear envelope breaks down
Chromosomes line up at the middle (metaphase plate)
Sister chromatids are pulled apart to opposite poles
Chromosomes decondense and two nuclei form
What is the ploidy and genetic relationship of daughter cells produced by mitosis?
Haploid and genetically unique
Diploid and genetically identical
Diploid and genetically unique
Haploid and genetically identical
Meiosis produces which outcome after two rounds of division?
Two diploid daughter cells identical to the parent
Four diploid daughter cells unique from the parent
Four haploid daughter cells that are genetically unique
Two haploid daughter cells identical to each other
Which separation occurs in Meiosis I according to the material?
Sister chromatids separate
Homologous chromosomes separate
Centromeres duplicate
Nuclear membranes fuse
What key event during Prophase I contributes directly to genetic variation?
Independent assortment of sister chromatids
Crossing over between homologous chromosomes
Random fusion of gametes
Mutation during DNA replication in G1
In which meiotic stage do homologous pairs line up at the middle?
Metaphase I
Anaphase I
Metaphase II
Prophase II
Which statement correctly contrasts Meiosis II with Mitosis based on the description?
Both separate homologous chromosomes
Meiosis II separates sister chromatids like mitosis does
Mitosis separates homologous chromosomes while Meiosis II does not
Neither separates sister chromatids
During anaphase of mitosis, what specifically is pulled apart?
Homologous chromosomes
Sister chromatids
Centrosomes
Nuclear envelopes
A cell with a diploid number (2n) completes meiosis. Which best describes the chromosome number in each resulting daughter cell?
2n, identical to the parent
n, identical to each other
n, unique from one another
2n, unique from one another
Which class of biomolecules has monosaccharides as monomers and polysaccharides as polymers?
Carbohydrates
Lipids
Proteins
Nucleic acids
The monomer of proteins is the amino acid, and the polymer is a polypeptide. What is a key function of proteins according to the material?
Primary energy storage only
Store and transmit genetic information
Serve as enzymes and provide structural and defense roles
Main component of cell membranes only
Which polymer stores and transmits genetic information?
Polysaccharide
Triglyceride
Polypeptide
DNA or RNA
Enzymes speed up chemical reactions primarily by which mechanism?
Raising the activation energy
Lowering the activation energy
Increasing the product concentration
Consuming substrate as fuel
What is the active site of an enzyme?
The region that binds inhibitors
The region that binds the substrate
A separate protein that activates enzymes
The site where products are released only
Each enzyme has an optimal pH. What is the effect of extreme pH (too acidic or too basic)?
It causes saturation
It increases substrate concentration
It causes denaturation
It has no effect on enzymes
How does increasing substrate concentration affect reaction rate before saturation?
The rate decreases steadily
The rate remains constant
The rate increases until all active sites are busy
The rate instantly reaches maximum and stays there
Which of the following pairs correctly matches a biomolecule with one of its listed functions?
Carbohydrates: long-term insulation
Lipids: main component of cell membranes and long-term energy storage
Proteins: store genetic information
Nucleic acids: primary source of energy
Which example is a carbohydrate polymer noted for plant energy storage?
Cellulose
Starch
Glycogen
Cholesterol
A reaction mixture contains an enzyme working at its optimal temperature and pH. Substrate concentration is gradually increased. Which observation is expected at high substrate concentration according to the material?
Enzyme rate drops due to denaturation
Enzyme activity becomes limited by product formation only
The enzyme becomes saturated and the rate levels off
The enzyme changes its amino acid sequence to improve binding
Which statement distinguishes lipids from the other listed biomolecules in the material?
They are true polymers built from repeating monomers
They are not true polymers and are grouped by hydrophobicity
They store and transmit genetic information
Their monomers are nucleotides
Which equation best represents photosynthesis as described?
C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP
6CO2 + 6H2O + light energy → C6H12O6 + 6O2
6O2 + C6H12O6 → 6CO2 + 6H2O + light energy
CO2 + H2O → CH4 + O2
Where do the light-dependent reactions of photosynthesis occur?
Stroma
Cytoplasm
Thylakoid membranes
Mitochondrial matrix
Which product is generated directly by the light-dependent reactions for use in the Calvin cycle?
Glucose
Pyruvate
ATP and NADPH
Acetyl-CoA
Which statement correctly describes the Calvin cycle according to the material?
It splits water to release O2
It uses CO2 and ATP/NADPH to build organic molecules
It occurs in thylakoid membranes
It generates most ATP by chemiosmosis
Which is the correct overall equation for cellular respiration given?
6CO2 + 6H2O + ATP → C6H12O6 + 6O2
C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP
C6H12O6 → ethanol + CO2
6O2 → 6H2O + ATP
Which stage of cellular respiration happens in the cytoplasm and is anaerobic?
Glycolysis
Pyruvate oxidation
Krebs cycle
Oxidative phosphorylation
What is the net gain from glycolysis per glucose molecule as listed?
4 ATP and 2 NADH
2 ATP and 2 NADH
2 ATP and 4 NADH
0 ATP and 2 NADH
Pyruvate oxidation converts each pyruvate into which molecule?
Glucose
Acetyl-CoA
Lactic acid
Ethanol
Per glucose, which outputs are associated with the Krebs cycle in the notes?
2 ATP, 6 NADH, 2 FADH2, 4 CO2
2 ATP only
28–34 ATP
Lactic acid and 2 ATP
During oxidative phosphorylation, which molecule acts as the final electron acceptor?
Carbon dioxide
NAD+
Oxygen (forming H2O)
FAD
What drives ATP synthesis as H+ ions flow back through ATP synthase?
Substrate-level phosphorylation in the cytosol
Energy from breaking glucose directly
Proton gradient across the inner mitochondrial membrane
Electron flow through chlorophyll
Which fermentation type is correctly matched with its typical organism/example?
Alcoholic fermentation — animals
Lactic acid fermentation — yeast
Lactic acid fermentation — animals and bacteria
Alcoholic fermentation — plants only
Approximately how many ATP are produced during oxidative phosphorylation according to the text?
2
4
10–12
Around 28–34
Which best describes ATP structure?
Ribose, adenine, and two phosphate groups
Deoxyribose, adenine, and three phosphate groups
Adenine, a ribose sugar, and three phosphate groups
Guanine, deoxyribose, and three phosphate groups
Energy is released for cellular work when which bond(s) of ATP are broken by hydrolysis?
Between adenine and ribose
Between the 2nd and 3rd phosphate groups
Between ribose and first phosphate only
Only within the nitrogenous base
What is the term for ATP regeneration from ADP and inorganic phosphate using energy from cellular respiration?
Photolysis
Phosphorylation
Carboxylation
Reduction
During photosynthesis, which molecule is split to release oxygen gas?
CO2
Glucose
Water
NADPH
Which statement best describes the overall flow of genetic information in the central dogma of biology?
Protein → RNA → DNA
DNA → RNA → Protein
RNA → DNA → Protein
DNA → Protein → RNA
Which base pairing rule is correct for DNA?
A pairs with C; G pairs with T
A pairs with T; G pairs with C
A pairs with U; G pairs with C
A pairs with G; T pairs with C
During DNA replication, which enzyme is primarily responsible for adding new complementary nucleotides to the template strand?
Helicase
Ligase
DNA Polymerase
RNA Polymerase
What does it mean that DNA replication is semiconservative?
Each new DNA molecule contains two new strands.
Each new DNA molecule contains one old and one new strand.
Only the leading strand is copied.
Replication occurs without enzymes.
Which statement distinguishes the leading and lagging strands during DNA replication?
Both are synthesized continuously from 3' to 5'.
Leading is discontinuous; lagging is continuous.
Leading is synthesized continuously 5'→3'; lagging is synthesized discontinuously in Okazaki fragments.
Both are synthesized discontinuously in Okazaki fragments.
Which enzyme joins Okazaki fragments on the lagging strand?
Helicase
Ligase
Topoisomerase
Primase
Which base in RNA replaces thymine (T) found in DNA during transcription?
Cytosine (C)
Uracil (U)
Adenine (A)
Guanine (G)
What is the role of RNA polymerase during transcription?
Joins Okazaki fragments
Binds to a gene's promoter, unzips DNA, and adds complementary RNA nucleotides
Transports amino acids to the ribosome
Synthesizes DNA from RNA
Which component carries the genetic message from the nucleus to the ribosome?
tRNA
mRNA
rRNA
DNA
During translation, what is the function of tRNA?
Serves as the workbench for protein synthesis
Carries codons to the nucleus
Has an anticodon that matches an mRNA codon and carries a specific amino acid
Synthesizes mRNA from DNA
Which term best describes ribosomes in the context of protein synthesis?
Genetic message
Translator
Workbench
Promoter
Which of the following is a defining structural feature of DNA?
Single-stranded with ribose sugar
Double helix with a sugar-phosphate backbone
Triple helix with deoxyribose sugar
Double helix with uracil
Antiparallel orientation of DNA strands means:
Both strands run 5' to 3'.
One strand runs 5' to 3' while the other runs 3' to 5'.
Both strands run 3' to 5'.
Strands run parallel in the same direction.
Which sequence correctly matches a point mutation subtype with its effect?
Silent: changes amino acid codon to a stop codon
Missense: results in a different amino acid
Nonsense: no change in the amino acid
Frameshift: swaps one base for another without insertion/deletion
Which statement about chromosomal mutations is supported by the material?
They involve a single base pair change.
They include deletion, duplication, inversion, and translocation.
They always result in a silent effect.
They are the same as point mutations.
In autosomal recessive disorders, which genotype description is accurate according to the material?
One copy of the dominant allele (Aa) is sufficient to be affected.
Carriers (Aa) are healthy, and two recessive alleles (aa) are required to be affected.
Only AA individuals are affected.
Heterozygotes (Aa) show full disease expression and are not carriers.
Which statement best defines a mutation?
A temporary change in protein shape
A permanent change in the DNA sequence
A random change in RNA after translation
A change in phenotype without genotype change
Which point mutation replaces one base with another without altering the amino acid sequence?
Missense substitution
Nonsense substitution
Silent substitution
Frameshift insertion
A single-base insertion that shifts the reading frame most directly leads to which outcome?
No change in protein length
Truncation at a stop codon with same frame
Usually a nonfunctional protein due to altered codons
Creation of a synonymous codon only
Which is NOT listed as a chromosomal mutation type?
Deletion
Inversion
Translocation
Base substitution
For an autosomal recessive disorder, which genotype represents a healthy carrier?
aa
AA
Aa
aAaa
Which inheritance pattern requires only one copy of the mutant allele (AA or Aa) to express the disease?
Autosomal recessive
Autosomal dominant
Polygenic
Mitochondrial
Sex-linked recessive traits are more common in which group and why?
Females, because they have two X chromosomes
Males, because they have only one X chromosome ( XA Y)
Females, due to X-inactivation
Males, due to Y-linked inheritance
Nondisjunction during meiosis most likely results in which condition listed?
Sickle-cell anemia
Hemophilia
Down Syndrome (Trisomy 21)
Cystic Fibrosis
Which term describes the observable traits of an organism, such as tall or short?
Genotype
Phenotype
Allele
Anticodon
According to the law of segregation, when do the two alleles for a trait separate?
During mitosis
During fertilization
During gamete formation (meiosis)
During DNA replication
In a monohybrid cross of Tt × Tt, what is the expected phenotypic ratio stated?
1:2:1
3:1
9:3:3:1
2:1
Which statement best distinguishes incomplete dominance from co-dominance?
Incomplete dominance shows a blended heterozygous phenotype; co-dominance fully and equally expresses both alleles
Both express only the dominant allele in heterozygotes
Incomplete dominance equally expresses both alleles; co-dominance blends them
Both produce identical phenotypes to homozygotes
Which example illustrates co-dominance as described?
Pink flowers from red × white
Blood type AB expressing both A and B antigens
Tall plants from TT genotype
Colorblindness in males
Under the Hardy-Weinberg principle, allele frequencies remain constant between generations if the population meets the required conditions. Which set includes two listed conditions for equilibrium?
No mutations and random mating
Natural selection and small population
Migration and nonrandom mating
Genetic drift and assortative mating
Which statement best describes an allele?
An observable trait of an organism
An alternative form of a gene
A diagram predicting offspring ratios
The complete genetic makeup of an organism
According to the Law of Segregation, what happens during gamete formation?
Alleles for different traits sort independently
Two alleles for a trait separate
Chromosomes fail to separate
Mutations increase genetic variation
In a monohybrid cross following Mendelian inheritance, what is the typical phenotypic ratio among the offspring?
1:1
3:1
9:3:3:1
1:2:1
Which condition is NOT required for Hardy-Weinberg equilibrium?
Random mating
No natural selection
Small population size
No gene flow (migration)
If p represents the frequency of the dominant allele and q represents the frequency of the recessive allele in a population, which equation must always hold under Hardy-Weinberg assumptions?
p + q = 0
p2+2pq+q2=0
p + q = 1
p2+q2=1
The heterozygous phenotype is a blend of the two homozygous phenotypes. Which non-Mendelian pattern is this?
Co-dominance
Incomplete dominance
Polygenic inheritance
Sex-linked recessive
Which scenario illustrates co-dominance?
Pink flowers from red and white parents
Tall plants resulting from two short parents
AB blood type expressing both A and B antigens
A continuous range of skin colors
Polygenic inheritance typically results in which pattern of phenotypes?
Discrete categories
A continuous range
Only two possible outcomes
Lethal alleles only
Which symbol is used to represent a female in a pedigree chart?
Square
Circle
Triangle
Diamond
In pedigree analysis, what does a half-shaded symbol indicate?
Affected individual
Unaffected individual
Carrier (known heterozygote)
Proband
Which biotechnology tool acts as "molecular scissors" that cut DNA at specific recognition sites?
Polymerase Chain Reaction (PCR)
Restriction enzymes
Gel electrophoresis
CRISPR-Cas9
What is the primary purpose of PCR?
Separating DNA fragments by size
Cutting DNA at specific sites
Making many copies of a specific DNA segment
Combining DNA from different sources
During gel electrophoresis, which fragments move faster and further through the gel?
Larger fragments
Smaller fragments
Fragments with no charge
Circular plasmids only
Which statement about CRISPR-Cas9 is accurate?
It is a vector used to carry genes into host cells
It is a technique to amplify DNA non-specifically
It allows precise cutting and modifying of DNA sequences
It separates DNA fragments by size
Which description best matches a plasmid in biotechnology?
A large linear chromosome used for replication
A small circular DNA used as a vector in bacteria
An RNA molecule that edits genes
A protein complex that cuts DNA
A population’s allele frequencies remain constant across generations when certain conditions are met. What does this statement define?
Law of Independent Assortment
Hardy-Weinberg Principle
Polygenic inheritance
Genetic drift
Which Mendelian principle states that alleles for different traits sort independently of one another?
Law of Segregation
Law of Independent Assortment
Linkage
Non-disjunction
Sex-linked recessive traits are typically more common in which group and why?
Females, because they have two X chromosomes
Males, because they have only one X chromosome
Females, due to mitochondrial inheritance
Males, because of Y-linked dominance
Which example best illustrates nondisjunction?
AB blood type in humans
Pink flowers from red and white parents
Down syndrome (Trisomy 21) due to failure of chromosome separation
A trait controlled by two or more genes
Which pairing correctly matches a technique with its function?
Recombinant DNA — separating DNA fragments by size
Gel electrophoresis — amplifying DNA
PCR — combining DNA from two sources
CRISPR-Cas9 — precise gene editing
Which is the correct genotype frequency expression under Hardy-Weinberg equilibrium?
p2+2pq+q2=1
p + q = 1
p2+pq+q2=1
2p + 2q = 1
Which statement defines a gene pool?
The total number of individuals in a population
All the alleles for all the genes in a population
How common a trait is in a population
Only dominant alleles present in a population
Which description best fits a phenotype?
The genetic makeup of an organism
The physical, observable trait
Two identical alleles
A heterozygous genotype
What is evolution as defined in this section?
The appearance of new species in a single generation
Change in allele frequencies in a population over time
Random mating in large populations
The process of DNA replication
In a dihybrid cross tracking two traits, what is the typical phenotypic ratio expected under independent assortment?
3:1
1:2:1
9:3:3:1
1:1:1:1
Which statement best defines evolution as presented in the material?
The appearance of new species in a single generation
The change in allele frequencies in a population over time
The survival of the fastest individuals regardless of genetics
The transformation of individuals during their lifetime
According to the principles of natural selection, which sequence lists the four key components in the correct logical order?
Variation → Overproduction → Differential Survival & Reproduction → Struggle for Existence
Overproduction → Variation → Struggle for Existence → Differential Survival & Reproduction
Struggle for Existence → Overproduction → Variation → Differential Survival & Reproduction
Differential Survival & Reproduction → Struggle for Existence → Overproduction → Variation
Which outcome is expected over generations as a result of natural selection?
Decrease in advantageous alleles
Increase in harmful mutations only
Stable allele frequencies regardless of environment
Increase in the frequency of advantageous alleles
Which feature distinguishes prokaryotic DNA from eukaryotic DNA in the comparison chart?
Prokaryotic DNA is linear and in the nucleus; eukaryotic DNA is circular in the cytoplasm
Prokaryotic DNA is circular in the cytoplasm; eukaryotic DNA is linear in the nucleus
Both have linear DNA in the cytoplasm
Both have circular DNA in the nucleus
Which cell type contains membrane-bound organelles according to the table?
Prokaryote
Eukaryote
Both prokaryote and eukaryote
Neither prokaryote nor eukaryote
Which process describes cell division in prokaryotes?
Meiosis
Mitosis
Binary fission
Budding
Which organisms are listed as examples of prokaryotes?
Animals and plants
Bacteria and Archaea
Fungi and plants
Animals and fungi
In the comparison table, which ribosome size is associated with eukaryotes?
70S
80S
50S
30S
Which statement about the nucleus is accurate based on the chart?
Prokaryotes have a nucleus; eukaryotes do not
Both prokaryotes and eukaryotes lack a nucleus
Eukaryotes have a nucleus; prokaryotes lack a nucleus (have nucleoid)
Only prokaryotes have multiple nuclei
Which principle of natural selection explains why not all offspring survive to reproduce?
Variation
Overproduction
Differential Survival & Reproduction (Fitness)
Result of evolution
Which stage of cell signaling involves a ligand binding to a specific receptor protein?
Reception
Transduction
Response
Amplification
During transduction in cell signaling, what commonly occurs within the cell?
Ligand synthesis
Signal transduction pathway such as a phosphorylation cascade
Exocytosis of receptors
DNA replication
Which outcome best represents the response stage of cell signaling?
Ligand binding
Second messenger formation
Gene expression or protein activation
Receptor endocytosis
Intracellular receptors most likely bind which type of ligand?
Large hydrophilic peptides
Ions that cannot cross membranes
Small hydrophobic molecules like steroid hormones
Neurotransmitters that require vesicles
Cell-surface receptors typically bind ligands that are:
Hydrophobic and membrane-permeable
Hydrophilic and cannot cross the membrane
Covalently attached to transport proteins
Only gases like O2 and CO2
Which is an example of negative feedback described in the material?
Blood clotting
Childbirth contractions increasing
Sweating to cool down when hot
Oxytocin release during labor
Positive feedback differs from negative feedback because it:
Reduces system instability
Amplifies or reinforces the initial stimulus
Maintains a constant set point
Stops once homeostasis is restored
Which blood component is correctly matched with its function according to the material?
Plasma: cell fragments that clot
Red blood cells: contain hemoglobin to transport O2
White blood cells: carry CO2
Platelets: part of the immune system
Which heart chambers receive blood?
Right and left ventricles
Right and left atria
Left atrium and right ventricle
Only the right atrium
Which vessel type carries blood away from the heart and typically has thick, muscular walls?
Veins
Capillaries
Arteries
Venules
What structural feature of veins helps prevent backflow of blood?
Thick muscular walls
Valves
One-cell-thick walls
Elastic lamellae only
Where does gas and nutrient exchange primarily occur within the circulatory system?
Aorta
Capillaries
Pulmonary artery
Vena cava
Which sequence correctly traces the pulmonary circuit described?
Right atrium → Right ventricle → Aorta → Lungs → Pulmonary vein
Right ventricle → Pulmonary artery → Lungs → Pulmonary vein → Left atrium
Left ventricle → Pulmonary artery → Lungs → Pulmonary vein → Right atrium
Right ventricle → Aorta → Lungs → Pulmonary vein → Left ventricle
Which structure is the primary site where gas exchange occurs in the lungs?
Trachea
Bronchi
Bronchioles
Alveoli
Gas exchange across alveolar and capillary walls occurs mainly by which process?
Active transport
Osmosis
Simple diffusion
Facilitated diffusion
During inhalation, which muscle action directly allows air to rush into the lungs?
Diaphragm relaxes and chest cavity shrinks
Diaphragm contracts and chest cavity expands
Rib muscles relax and chest cavity expands
Abdominal muscles contract and pressure increases
Which statement best describes oxygen movement in the lungs during gas exchange?
O2 diffuses from blood into the alveoli
O2 diffuses from alveoli into the blood
O2 is pumped into blood by active transport
O2 binds CO2 to enter the blood
What is the main function of the respiratory system as described?
Exchange nutrients with tissues
Transport hormones
Take in O2 and release CO2
Generate electrical impulses
Which sequence correctly traces the path of air from entry to the site of gas exchange?
Pharynx → Nose/Mouth → Larynx → Alveoli
Nose/Mouth → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli
Mouth → Esophagus → Stomach → Alveoli
Trachea → Larynx → Pharynx → Bronchi → Alveoli
Which description correctly matches exhalation with muscle activity and chest cavity changes?
Active process; diaphragm contracts, pressure drops
Passive process; diaphragm and rib muscles relax, pressure rises
Active process; rib muscles contract, pressure rises
Passive process; diaphragm contracts, chest cavity expands
Which is the primary function of the digestive system?
Deliver oxygen to tissues
Protect against pathogens
Mechanical and chemical breakdown of food for absorption
Coordinate all body functions via hormones
Which process propels food through the esophagus to the stomach?
Ciliary movement
Peristalsis
Active pumping
Simple diffusion
Which pairing of organ and digestive function is correct?
Stomach—chemical digestion of carbohydrates by amylase
Mouth—mechanical digestion and chemical digestion of carbohydrates by salivary amylase
Large intestine—primary site of chemical digestion
Small intestine—stores bile for later use
Which statement about the small intestine is accurate?
It is the primary site of water absorption only
It receives bile to emulsify fats and pancreatic enzymes to digest biomolecules
It stores feces for elimination
It digests proteins only using pepsin
What structural features increase the small intestine’s surface area for absorption?
Rugae
Villi and microvilli
Goblet cells
Cilia
Which accessory organ stores bile?
Liver
Gallbladder
Pancreas
Appendix
Which characteristic distinguishes the nervous system’s signaling from the endocrine system’s?
Uses chemical hormones released into blood
Signals are long-lasting
Uses electrical impulses and chemical neurotransmitters; very fast and short-lived
Organized solely as glands
Which structure is the key link integrating the nervous and endocrine systems by controlling the pituitary gland?
Thyroid
Hypothalamus
Adrenal cortex
Cerebellum
Which description of innate immunity is most accurate?
A slow, specific response that remembers pathogens
First line of defense including skin and mucous membranes with phagocytes and inflammation
Antibody production by T-cells
Requires prior exposure to be effective
In adaptive immunity, which cells mediate the humoral response?
Macrophages
Neutrophils
B-cells
Helper T-cells only
