BIO 2A03 FINAL EXAM | ACTUAL 217 QUESTIONS AND
ANSWERS | WITH COMPLETE SOLUTIONS - 2026 UPDATE.
Purpose of mitochondrial respiration Answer - To supply the ATP needed for
cellular functions
External Respiration Answer - The movement of oxygen from the environment
into the cell and carbon dioxide out
Internal Respiration Answer - The metabolic process of cellular respiration
occurring within the mitochondria
The Oxygen Cascade Answer - The sequential series of steps moving oxygen
from the environment to the mitochondria including ventilation diffusion
circulation tissue perfusion and cellular utilization
Why small animals can rely on simple diffusion Answer - Because they have a
large Surface Area to Volume (SA:V) ratio
Fick's First Law Answer - Solutes move from high to low concentration across a
gradient
Fick's Second Law Answer - Diffusion is proportional to surface area and
inversely proportional to distance
,Gills Answer - Evaginations of the body surface used for gas exchange
Lungs Answer - Invaginations of the body surface that form an internal cavity
for gas exchange
Countercurrent Exchange in fish Answer - Water flows in one direction across
gills while blood flows in the opposite direction to maintain a constant diffusion
gradient
Spiracular Breathing in insects Answer - Tracheal system of air-filled tubes
bringing oxygen directly to aerobic tissues
Spiracles Answer - Openings that control airflow into the trachea control water
loss and keep dust out
Lung Ventilation in birds Answer - Rely on extensible air sacs and require two
full cycles of inhalation and exhalation to move one breath through rigid lungs
Crosscurrent Exchange in birds Answer - Air flows in one direction
perpendicular to the flow of blood in the parabronchi
Conducting Zone of Respiratory Tract Answer - Upper airways and bronchi
reinforced with cartilage that conduct air but perform no gas exchange
Respiratory Zone of Respiratory Tract Answer - Includes bronchioles and alveoli
acting as the site of gas exchange
Dalton's Law Answer - Total pressure of a gas mixture is the sum of the partial
pressures of its individual gases
, Boyle's Law Answer - The pressure of a gas is inversely proportional to the
volume of its container
Henry's Law Answer - The concentration of a gas in a liquid is directly
proportional to its solubility and its partial pressure
Intrapleural Pressure Answer - The pressure within the pleural sac that is
always sub-atmospheric (negative) to prevent lung collapse
Muscles used in active inhalation Answer - External intercostal muscles and
the diaphragm
Quiet or resting exhalation Answer - A passive process driven by the elastic
recoil of the lungs and chest wall
Type II Alveolar Cells Answer - Cells that produce surfactant which reduces
surface tension and improves lung compliance
Hemoglobin Structure Answer - A tetrameric protein consisting of 4 globin
chains and 4 heme groups
Hemoglobin Cooperativity Answer - Allosteric modulation where the binding
of one O2 molecule changes the shape of the protein making it easier for
subsequent O2 molecules to bind
Venous Reserve Answer - Blood leaving resting tissues is still 75% saturated
with oxygen to ensure availability if demand suddenly increases
ANSWERS | WITH COMPLETE SOLUTIONS - 2026 UPDATE.
Purpose of mitochondrial respiration Answer - To supply the ATP needed for
cellular functions
External Respiration Answer - The movement of oxygen from the environment
into the cell and carbon dioxide out
Internal Respiration Answer - The metabolic process of cellular respiration
occurring within the mitochondria
The Oxygen Cascade Answer - The sequential series of steps moving oxygen
from the environment to the mitochondria including ventilation diffusion
circulation tissue perfusion and cellular utilization
Why small animals can rely on simple diffusion Answer - Because they have a
large Surface Area to Volume (SA:V) ratio
Fick's First Law Answer - Solutes move from high to low concentration across a
gradient
Fick's Second Law Answer - Diffusion is proportional to surface area and
inversely proportional to distance
,Gills Answer - Evaginations of the body surface used for gas exchange
Lungs Answer - Invaginations of the body surface that form an internal cavity
for gas exchange
Countercurrent Exchange in fish Answer - Water flows in one direction across
gills while blood flows in the opposite direction to maintain a constant diffusion
gradient
Spiracular Breathing in insects Answer - Tracheal system of air-filled tubes
bringing oxygen directly to aerobic tissues
Spiracles Answer - Openings that control airflow into the trachea control water
loss and keep dust out
Lung Ventilation in birds Answer - Rely on extensible air sacs and require two
full cycles of inhalation and exhalation to move one breath through rigid lungs
Crosscurrent Exchange in birds Answer - Air flows in one direction
perpendicular to the flow of blood in the parabronchi
Conducting Zone of Respiratory Tract Answer - Upper airways and bronchi
reinforced with cartilage that conduct air but perform no gas exchange
Respiratory Zone of Respiratory Tract Answer - Includes bronchioles and alveoli
acting as the site of gas exchange
Dalton's Law Answer - Total pressure of a gas mixture is the sum of the partial
pressures of its individual gases
, Boyle's Law Answer - The pressure of a gas is inversely proportional to the
volume of its container
Henry's Law Answer - The concentration of a gas in a liquid is directly
proportional to its solubility and its partial pressure
Intrapleural Pressure Answer - The pressure within the pleural sac that is
always sub-atmospheric (negative) to prevent lung collapse
Muscles used in active inhalation Answer - External intercostal muscles and
the diaphragm
Quiet or resting exhalation Answer - A passive process driven by the elastic
recoil of the lungs and chest wall
Type II Alveolar Cells Answer - Cells that produce surfactant which reduces
surface tension and improves lung compliance
Hemoglobin Structure Answer - A tetrameric protein consisting of 4 globin
chains and 4 heme groups
Hemoglobin Cooperativity Answer - Allosteric modulation where the binding
of one O2 molecule changes the shape of the protein making it easier for
subsequent O2 molecules to bind
Venous Reserve Answer - Blood leaving resting tissues is still 75% saturated
with oxygen to ensure availability if demand suddenly increases
