DAT TEST PAPER QUESTIONS AND
SOLUTIONS COMPLETE REVIEW MATERIAL
●● What is negative feedback?
Answer: Bringing conditions back to their normal or homeostatic
function
●● What is positive feedback?
Answer: Feedback that increases the output of a process.
●● What is respiration?
Answer: Movement of gases in and out; can also mean cellular
respiration in which ATP is produced in the mitochondria
●● What is thermoregulation?
Answer: Control of exchange of heat with the environment
a. Ectotherms/poikilotherms/cold-blooded - obtained their body heat
from the environment
b. endotherms/homeotherms/warmblooded - generate their own body
heat and have higher basal metabolic rate than ectotherms.
●● What is the difference between external respiration and internal
respiration?
,Answer: External respiration is basically breathing. Internal respiration
is cell respiration
●● A breakdown of Invertebrate Respiration
Answer: a. Cnidaria (Protozoa and Hydra) - simple diffusion of gases
from the environment into the body (sufficient for small animals only)
b. Annelids - they secrete mucus that provides a moist surface for
gaseous exchange to take place (diffusion). The circulatory system
brings oxygen to cells
c. Anthropods - Grasshoppers ( have series of chitin-lined respiratory
tubules called trachea that open to the surface via openings called
spiracles). Spiders (Book lungs)
d. Fish - Gills
●● Countercurrent exchange in fish
Answer: The exchange between opposing movements of water and
underlying blood that maximizes diffusion of oxygen into the blood and
carbon dioxide into water. ( The water has a higher concentration of
oxygen while the blood has a lower concentration of oxygen. Oxygen
will flow from the water into the blood).
●● Describe the lungs
Answer: These are invaginated structures made of two sub-portions (left
lung and the right lung). The left lung is smaller and consist of 2 lobes,
the right lung is made up of 3 lobes. The left lung is smaller in order to
accommodate the heart.
,●● What is the name given to the membranous cover of the lung?
Answer: Pleurae. There are two layers of pleurae; visceral and parietal
pleura. The space between these layers is the intra pleural space .
●● What is the function of the visceral pleura ?
Answer: covers the lungs
●● What is the function of the parietal pleura?
Answer: covers the diaphragm
●● Sequence of events during exhaling
Answer: Diaphragm rises - volume in lungs decreases - pressure inside
the lungs increase relative to the atmosphere - air rushes out.
●● How is CO2 transported in the blood?
Answer: - Bicarbonate (primary)
- Dissolved in the plasma
- Bound to hemoglobin
The enzyme responsible for catalyzing the conversion of CO2 to HCO3-
is carbonic anhydrase.
●● Structures and functions of parts of the lung
, Answer: Alveoli- where gas exchange between the circulatory system
and lungs occur. There are two types of epithelial cells in human alveoli
( type 1 (structural support) and type 2 (produce surfactant)).
Nose- Filters and moistens in coming air
Pharynx - throat, passageway for food and air
Larynx - voice box, if non gas enter here it results in coughing
trachea - epiglottis covers the trachea during swallowing ; contains C
shaped ringed cartilage covered by ciliated mucus cells
bronchi - two bronchi enters the lungs and branch into narrower
bronchioles
Alveoli - Each bronchioles branches ends in these small sacs
●● What are some detailed sequences of gas exchange?
Answer: Diffusion between alveolar chambers and blood ( O2 diffuses
into the blood)
bulk flow of O2 - O2 is transported through the body within hemoglobin
containing red blood cells
Diffusion of O2 from the blood into cells
Bulk flow of CO2 - it is mainly transported through plasma as
bicarbonate.
●● Bohr effect
Answer: hemoglobin's oxygen binding affinity is inversely related both
to acidity and to the concentration of carbon dioxide. If there is more
SOLUTIONS COMPLETE REVIEW MATERIAL
●● What is negative feedback?
Answer: Bringing conditions back to their normal or homeostatic
function
●● What is positive feedback?
Answer: Feedback that increases the output of a process.
●● What is respiration?
Answer: Movement of gases in and out; can also mean cellular
respiration in which ATP is produced in the mitochondria
●● What is thermoregulation?
Answer: Control of exchange of heat with the environment
a. Ectotherms/poikilotherms/cold-blooded - obtained their body heat
from the environment
b. endotherms/homeotherms/warmblooded - generate their own body
heat and have higher basal metabolic rate than ectotherms.
●● What is the difference between external respiration and internal
respiration?
,Answer: External respiration is basically breathing. Internal respiration
is cell respiration
●● A breakdown of Invertebrate Respiration
Answer: a. Cnidaria (Protozoa and Hydra) - simple diffusion of gases
from the environment into the body (sufficient for small animals only)
b. Annelids - they secrete mucus that provides a moist surface for
gaseous exchange to take place (diffusion). The circulatory system
brings oxygen to cells
c. Anthropods - Grasshoppers ( have series of chitin-lined respiratory
tubules called trachea that open to the surface via openings called
spiracles). Spiders (Book lungs)
d. Fish - Gills
●● Countercurrent exchange in fish
Answer: The exchange between opposing movements of water and
underlying blood that maximizes diffusion of oxygen into the blood and
carbon dioxide into water. ( The water has a higher concentration of
oxygen while the blood has a lower concentration of oxygen. Oxygen
will flow from the water into the blood).
●● Describe the lungs
Answer: These are invaginated structures made of two sub-portions (left
lung and the right lung). The left lung is smaller and consist of 2 lobes,
the right lung is made up of 3 lobes. The left lung is smaller in order to
accommodate the heart.
,●● What is the name given to the membranous cover of the lung?
Answer: Pleurae. There are two layers of pleurae; visceral and parietal
pleura. The space between these layers is the intra pleural space .
●● What is the function of the visceral pleura ?
Answer: covers the lungs
●● What is the function of the parietal pleura?
Answer: covers the diaphragm
●● Sequence of events during exhaling
Answer: Diaphragm rises - volume in lungs decreases - pressure inside
the lungs increase relative to the atmosphere - air rushes out.
●● How is CO2 transported in the blood?
Answer: - Bicarbonate (primary)
- Dissolved in the plasma
- Bound to hemoglobin
The enzyme responsible for catalyzing the conversion of CO2 to HCO3-
is carbonic anhydrase.
●● Structures and functions of parts of the lung
, Answer: Alveoli- where gas exchange between the circulatory system
and lungs occur. There are two types of epithelial cells in human alveoli
( type 1 (structural support) and type 2 (produce surfactant)).
Nose- Filters and moistens in coming air
Pharynx - throat, passageway for food and air
Larynx - voice box, if non gas enter here it results in coughing
trachea - epiglottis covers the trachea during swallowing ; contains C
shaped ringed cartilage covered by ciliated mucus cells
bronchi - two bronchi enters the lungs and branch into narrower
bronchioles
Alveoli - Each bronchioles branches ends in these small sacs
●● What are some detailed sequences of gas exchange?
Answer: Diffusion between alveolar chambers and blood ( O2 diffuses
into the blood)
bulk flow of O2 - O2 is transported through the body within hemoglobin
containing red blood cells
Diffusion of O2 from the blood into cells
Bulk flow of CO2 - it is mainly transported through plasma as
bicarbonate.
●● Bohr effect
Answer: hemoglobin's oxygen binding affinity is inversely related both
to acidity and to the concentration of carbon dioxide. If there is more
