EXCHANGE SURFACES Test Exam Questions And
Answers Verified 100% Correct
What is at the end of the tracheoles in insects? - ANSWER tracheal fluid
oxygen diffuses faster in air than it does in water so tracheal fluid is a
barrier to oxygen diffusion
when insect is active more SA of muscle is exposed so more O2 can diffuse
structure of gills - ANSWER gills composed of thousands of filaments.
each filament is covered in lamallae
lamallae are thin so diffusion pathway of O2 from water into blood is short and they
increase SA
large SA, good blood supply
operculum (bony flap) protects gills
What do fish need to maintain for efficient gas exchange? - ANSWER Continuous flow
of water over the gills
explain process of ventilation in fish - ANSWER water is constantly pushed over gill
filaments for constant supply of O2:
- fish mouth opens, buccal cavity lowered, increases volume of buccal cavity
- pressure now lower in buccal cavity than outside pressure so water flows in
- fish mouth closes, buccal cavity raised, increased pressure pushes water into gill
cavity (has lower pressure)
- pressure builds up in gill cavity which forces open the operculum and water is pushed
out
*when buccal cavity is lowered has effect of forcing operculum shut
What is counter current flow in fish - ANSWER - water flowing over gills and blood in
,gill filaments flow in different directions
- it ensures that all the way across the gill filament, blood constantly meets water with
higher O2 conc than it has, maintains diffusion gradient
How do fish slow the movement of water to allow more time for gas exchange? -
ANSWER Tips of adjacent gill filaments overlap
How does a countercurrent exchange system help fish with gas exchange? - ANSWER
Maintains steep concentration gradient
3.1.1 EXCHANGE SURFACES - ANSWER 3.1.1 EXCHANGE SURFACES
3.1.2 TRANSPORT IN ANIMALS - ANSWER 3.1.2 TRANSPORT IN ANIMALS
purpose of transport systems - ANSWER - supply nutrients + oxygen
- remove waste products
- hormone circulation
- temp maintenance
- immune responses
Why do multi-cellular animals need transport systems? - ANSWER - metabolic
demands high → greater demand for oxygen + waste removal
- SA:V ratio smaller as animals get bigger so diffusion distances bigger
- diffusion pathway increases as size of animal increases → need short diff. pathway to
supply cells efficiently
if relied on diffusion would be too slow
Which circulatory system is found in insects? - ANSWER Open
- pumped straight from heart into body cavity
How it works:
- open body cavity = haemocoel
- insect blood = haemolymph → transports waste + food
- haemocoel = low pressure
- haemocoel has direct contact with tissues + cells → where exchange take place
between haemolymph + cells
, - haemolymph then returns to the heart
- don't rely on circulatory system to transport O2/CO2
what is a closed circulatory system? - ANSWER blood confined to blood vessels and
has no direct contact with cells
distribution of blood to diff tissues can be adjusted
Which circulatory system is found in fish? - ANSWER single closed
how it works:
- blood travels only once through the heart for each complete circulation of the body
- O2 poor blood pumped from atrium to ventricle
- O2 poor transported to gill capillaries to get oxidised
- O2 rich blood transported to body capillaries and O2 gets used up
- back to heart (2 chambers)
How can fish so active with an inefficient single closed system? - ANSWER usually
blood returns to heart slowly which limits exchange process → less active
but fish have have countercurrent gaseous system that means they can take up lots of
O2
also don't maintain body temp
reduces metabolic demand
Which circulatory system is found in mammals? - ANSWER double closed
how it works:
- blood is pumped from the right side of heart to the lungs to pick up O2 + unload CO2
- blood flows back through left side of the heart and pumped out to be transported to
body tissues
- returns to heart
extra:
- blood travels x2
- 4 chambered heart
Answers Verified 100% Correct
What is at the end of the tracheoles in insects? - ANSWER tracheal fluid
oxygen diffuses faster in air than it does in water so tracheal fluid is a
barrier to oxygen diffusion
when insect is active more SA of muscle is exposed so more O2 can diffuse
structure of gills - ANSWER gills composed of thousands of filaments.
each filament is covered in lamallae
lamallae are thin so diffusion pathway of O2 from water into blood is short and they
increase SA
large SA, good blood supply
operculum (bony flap) protects gills
What do fish need to maintain for efficient gas exchange? - ANSWER Continuous flow
of water over the gills
explain process of ventilation in fish - ANSWER water is constantly pushed over gill
filaments for constant supply of O2:
- fish mouth opens, buccal cavity lowered, increases volume of buccal cavity
- pressure now lower in buccal cavity than outside pressure so water flows in
- fish mouth closes, buccal cavity raised, increased pressure pushes water into gill
cavity (has lower pressure)
- pressure builds up in gill cavity which forces open the operculum and water is pushed
out
*when buccal cavity is lowered has effect of forcing operculum shut
What is counter current flow in fish - ANSWER - water flowing over gills and blood in
,gill filaments flow in different directions
- it ensures that all the way across the gill filament, blood constantly meets water with
higher O2 conc than it has, maintains diffusion gradient
How do fish slow the movement of water to allow more time for gas exchange? -
ANSWER Tips of adjacent gill filaments overlap
How does a countercurrent exchange system help fish with gas exchange? - ANSWER
Maintains steep concentration gradient
3.1.1 EXCHANGE SURFACES - ANSWER 3.1.1 EXCHANGE SURFACES
3.1.2 TRANSPORT IN ANIMALS - ANSWER 3.1.2 TRANSPORT IN ANIMALS
purpose of transport systems - ANSWER - supply nutrients + oxygen
- remove waste products
- hormone circulation
- temp maintenance
- immune responses
Why do multi-cellular animals need transport systems? - ANSWER - metabolic
demands high → greater demand for oxygen + waste removal
- SA:V ratio smaller as animals get bigger so diffusion distances bigger
- diffusion pathway increases as size of animal increases → need short diff. pathway to
supply cells efficiently
if relied on diffusion would be too slow
Which circulatory system is found in insects? - ANSWER Open
- pumped straight from heart into body cavity
How it works:
- open body cavity = haemocoel
- insect blood = haemolymph → transports waste + food
- haemocoel = low pressure
- haemocoel has direct contact with tissues + cells → where exchange take place
between haemolymph + cells
, - haemolymph then returns to the heart
- don't rely on circulatory system to transport O2/CO2
what is a closed circulatory system? - ANSWER blood confined to blood vessels and
has no direct contact with cells
distribution of blood to diff tissues can be adjusted
Which circulatory system is found in fish? - ANSWER single closed
how it works:
- blood travels only once through the heart for each complete circulation of the body
- O2 poor blood pumped from atrium to ventricle
- O2 poor transported to gill capillaries to get oxidised
- O2 rich blood transported to body capillaries and O2 gets used up
- back to heart (2 chambers)
How can fish so active with an inefficient single closed system? - ANSWER usually
blood returns to heart slowly which limits exchange process → less active
but fish have have countercurrent gaseous system that means they can take up lots of
O2
also don't maintain body temp
reduces metabolic demand
Which circulatory system is found in mammals? - ANSWER double closed
how it works:
- blood is pumped from the right side of heart to the lungs to pick up O2 + unload CO2
- blood flows back through left side of the heart and pumped out to be transported to
body tissues
- returns to heart
extra:
- blood travels x2
- 4 chambered heart
