traighterline Anatomy &
S
Physiology I Midterm Exam Review
2026-2027 | Latest Update |
Questions & Verified Answers |
100% Correct | Grade A | Pass
Guaranteed
## PART A – MULTIPLE CHOICE (Q1–60)
1 (Chemistry – Atomic Structure):** Which subatomic particle is responsible for the chemical
Q
bonding properties of an atom?
. Neutron
A
B. Proton
C. Electron
D. Nucleon
**[CORRECT]** C
* Rationale: Electrons occupy the outermost energy shells (valence electrons) and participate in
chemical bonding through sharing, gaining, or losing. Protons and neutrons are located in the
nucleus and do not participate in bonding; protons determine atomic number but not bonding
behavior. On Straighterline exams, always distinguish between particles that determine identity
(protons) versus those that determine reactivity (electrons).*
---
* *Q2 (Chemistry – pH):** A solution with a pH of 3.0 is how many times more acidic than a
solution with a pH of 6.0?
A. 3 times
, . 10 times
B
C. 100 times
D. 1,000 times
**[CORRECT]** D
* Rationale: The pH scale is logarithmic (base 10); each whole number change represents a
10-fold difference in H⁺ concentration, so a 3-unit difference equals 10³ = 1,000. Students often
mistakenly subtract the values (6-3=3) without applying the logarithmic relationship. For
Straighterline, remember: pH difference = exponent; 10^(difference) = fold change.*
---
* *Q3 (Chemistry – Macromolecules):** Which macromolecule is composed of amino acid
monomers linked by peptide bonds?
. Carbohydrate
A
B. Lipid
C. Protein
D. Nucleic acid
**[CORRECT]** C
* Rationale: Proteins are polymers of amino acids joined by dehydration synthesis forming
peptide bonds between the carboxyl group of one amino acid and the amino group of another.
Carbohydrates use glycosidic bonds, lipids are not true polymers, and nucleic acids use
phosphodiester bonds. Straighterline frequently tests bond types—memorize peptide (protein),
glycosidic (carbohydrate), phosphodiester (nucleic acid), and ester (lipid).*
---
* *Q4 (Chemistry – Buffers):** Which buffer system is most important for maintaining blood pH
homeostasis?
. Phosphate buffer system
A
B. Protein buffer system
C. Carbonic acid-bicarbonate buffer system
D. Ammonia buffer system
**[CORRECT]** C
* Rationale: The carbonic acid-bicarbonate system (H₂CO₃/HCO₃⁻) is the primary blood buffer
because CO₂ (which forms carbonic acid) is rapidly regulated by the lungs and kidneys, allowing
both respiratory and renal compensation. While phosphate and protein buffers exist, they are
, econdary; the phosphate system is more important in intracellular and renal tubular fluids.
s
Straighterline often asks about the "most important" system—always select carbonic
acid-bicarbonate for blood pH.*
---
* *Q5 (Cell Biology – Organelles):** Which organelle is responsible for modifying, sorting, and
packaging proteins for secretion?
. Mitochondrion
A
B. Rough endoplasmic reticulum
C. Golgi apparatus
D. Lysosome
**[CORRECT]** C
* Rationale: The Golgi apparatus receives proteins from the rough ER, modifies them
(glycosylation), sorts them, and packages them into vesicles for secretion or delivery to other
organelles. The rough ER synthesizes proteins but does not package them; mitochondria
produce ATP; lysosomes digest waste. On Straighterline exams, associate "packaging and
shipping" with the Golgi—think of it as the cell's post office.*
---
* *Q6 (Cell Biology – Membrane Transport):** The movement of water across a selectively
permeable membrane from an area of low solute concentration to high solute concentration is
called:
. Diffusion
A
B. Active transport
C. Osmosis
D. Facilitated diffusion
**[CORRECT]** C
* Rationale: Osmosis is specifically the passive movement of water across a semipermeable
membrane down its concentration gradient (from low solute/high water to high solute/low water).
Diffusion applies to solutes, active transport requires ATP and moves against gradients, and
facilitated diffusion uses carrier proteins for solutes. Straighterline tests the distinction between
solute movement (diffusion) and water movement (osmosis) frequently.*
---
, * *Q7 (Cell Biology – Membrane Transport):** A red blood cell placed in a hypertonic solution
will:
. Swell and burst (lyse)
A
B. Shrink (crenate)
C. Remain unchanged
D. Divide by mitosis
**[CORRECT]** B
* Rationale: In a hypertonic solution, the extracellular solute concentration exceeds intracellular
concentration, causing water to move out of the cell by osmosis, leading to cell shrinkage
(crenation). Hypotonic solutions cause lysis; isotonic solutions maintain equilibrium.
Straighterline uses the mnemonic "hyper = shrink, hypo = swell"—remember the "o" in hypo
looks like a swollen cell.*
---
* *Q8 (Cell Biology – Membrane Transport):** Which transport mechanism requires ATP and
moves substances against their concentration gradient?
. Simple diffusion
A
B. Facilitated diffusion
C. Primary active transport
D. Osmosis
**[CORRECT]** C
* Rationale: Primary active transport directly uses ATP to pump substances against their
electrochemical gradient (e.g., Na⁺/K⁺-ATPase). Simple and facilitated diffusion are passive (no
ATP, down gradient); osmosis is passive water movement. Straighterline often contrasts primary
active transport (direct ATP use) with secondary active transport (uses ion gradients); for
"against gradient + ATP," select primary active transport.*
---
* *Q9 (Cell Biology – Mitosis):** During which phase of mitosis do the chromosomes align at the
metaphase plate?
. Prophase
A
B. Metaphase
C. Anaphase
D. Telophase
S
Physiology I Midterm Exam Review
2026-2027 | Latest Update |
Questions & Verified Answers |
100% Correct | Grade A | Pass
Guaranteed
## PART A – MULTIPLE CHOICE (Q1–60)
1 (Chemistry – Atomic Structure):** Which subatomic particle is responsible for the chemical
Q
bonding properties of an atom?
. Neutron
A
B. Proton
C. Electron
D. Nucleon
**[CORRECT]** C
* Rationale: Electrons occupy the outermost energy shells (valence electrons) and participate in
chemical bonding through sharing, gaining, or losing. Protons and neutrons are located in the
nucleus and do not participate in bonding; protons determine atomic number but not bonding
behavior. On Straighterline exams, always distinguish between particles that determine identity
(protons) versus those that determine reactivity (electrons).*
---
* *Q2 (Chemistry – pH):** A solution with a pH of 3.0 is how many times more acidic than a
solution with a pH of 6.0?
A. 3 times
, . 10 times
B
C. 100 times
D. 1,000 times
**[CORRECT]** D
* Rationale: The pH scale is logarithmic (base 10); each whole number change represents a
10-fold difference in H⁺ concentration, so a 3-unit difference equals 10³ = 1,000. Students often
mistakenly subtract the values (6-3=3) without applying the logarithmic relationship. For
Straighterline, remember: pH difference = exponent; 10^(difference) = fold change.*
---
* *Q3 (Chemistry – Macromolecules):** Which macromolecule is composed of amino acid
monomers linked by peptide bonds?
. Carbohydrate
A
B. Lipid
C. Protein
D. Nucleic acid
**[CORRECT]** C
* Rationale: Proteins are polymers of amino acids joined by dehydration synthesis forming
peptide bonds between the carboxyl group of one amino acid and the amino group of another.
Carbohydrates use glycosidic bonds, lipids are not true polymers, and nucleic acids use
phosphodiester bonds. Straighterline frequently tests bond types—memorize peptide (protein),
glycosidic (carbohydrate), phosphodiester (nucleic acid), and ester (lipid).*
---
* *Q4 (Chemistry – Buffers):** Which buffer system is most important for maintaining blood pH
homeostasis?
. Phosphate buffer system
A
B. Protein buffer system
C. Carbonic acid-bicarbonate buffer system
D. Ammonia buffer system
**[CORRECT]** C
* Rationale: The carbonic acid-bicarbonate system (H₂CO₃/HCO₃⁻) is the primary blood buffer
because CO₂ (which forms carbonic acid) is rapidly regulated by the lungs and kidneys, allowing
both respiratory and renal compensation. While phosphate and protein buffers exist, they are
, econdary; the phosphate system is more important in intracellular and renal tubular fluids.
s
Straighterline often asks about the "most important" system—always select carbonic
acid-bicarbonate for blood pH.*
---
* *Q5 (Cell Biology – Organelles):** Which organelle is responsible for modifying, sorting, and
packaging proteins for secretion?
. Mitochondrion
A
B. Rough endoplasmic reticulum
C. Golgi apparatus
D. Lysosome
**[CORRECT]** C
* Rationale: The Golgi apparatus receives proteins from the rough ER, modifies them
(glycosylation), sorts them, and packages them into vesicles for secretion or delivery to other
organelles. The rough ER synthesizes proteins but does not package them; mitochondria
produce ATP; lysosomes digest waste. On Straighterline exams, associate "packaging and
shipping" with the Golgi—think of it as the cell's post office.*
---
* *Q6 (Cell Biology – Membrane Transport):** The movement of water across a selectively
permeable membrane from an area of low solute concentration to high solute concentration is
called:
. Diffusion
A
B. Active transport
C. Osmosis
D. Facilitated diffusion
**[CORRECT]** C
* Rationale: Osmosis is specifically the passive movement of water across a semipermeable
membrane down its concentration gradient (from low solute/high water to high solute/low water).
Diffusion applies to solutes, active transport requires ATP and moves against gradients, and
facilitated diffusion uses carrier proteins for solutes. Straighterline tests the distinction between
solute movement (diffusion) and water movement (osmosis) frequently.*
---
, * *Q7 (Cell Biology – Membrane Transport):** A red blood cell placed in a hypertonic solution
will:
. Swell and burst (lyse)
A
B. Shrink (crenate)
C. Remain unchanged
D. Divide by mitosis
**[CORRECT]** B
* Rationale: In a hypertonic solution, the extracellular solute concentration exceeds intracellular
concentration, causing water to move out of the cell by osmosis, leading to cell shrinkage
(crenation). Hypotonic solutions cause lysis; isotonic solutions maintain equilibrium.
Straighterline uses the mnemonic "hyper = shrink, hypo = swell"—remember the "o" in hypo
looks like a swollen cell.*
---
* *Q8 (Cell Biology – Membrane Transport):** Which transport mechanism requires ATP and
moves substances against their concentration gradient?
. Simple diffusion
A
B. Facilitated diffusion
C. Primary active transport
D. Osmosis
**[CORRECT]** C
* Rationale: Primary active transport directly uses ATP to pump substances against their
electrochemical gradient (e.g., Na⁺/K⁺-ATPase). Simple and facilitated diffusion are passive (no
ATP, down gradient); osmosis is passive water movement. Straighterline often contrasts primary
active transport (direct ATP use) with secondary active transport (uses ion gradients); for
"against gradient + ATP," select primary active transport.*
---
* *Q9 (Cell Biology – Mitosis):** During which phase of mitosis do the chromosomes align at the
metaphase plate?
. Prophase
A
B. Metaphase
C. Anaphase
D. Telophase
