BSCI207 MIDTERM 1, 3+ AFTER CONCEPT CHECKS AND
GAE UPDATED ACTUAL QUESTIONS AND CORRECT
ANSWERS
Question:
1. Multicellular terrestrial organisms use a gas exchange system coupled to circulatory system. There are
several steps required to get oxygen from the air to the tissues in the body that need it. Pick the correct
answers to complete the sentence describing these steps: Animals fulfill their oxygen needs by having
oxygen move by------- to the lungs, by ------ into the blood stream, by ----- to an organ in the body, and by
-----into the cells of that tissue.
Answer:
Answer 1:bulk flow Answer 2:diffusion Answer 3:bulk flow Answer 4:diffusion
Question:
2. Gas exchange systems utilize diffusion and the diffusion rate can be described by Fick's law: In trying to
maximize the diffusion rate, what aspects of the system, as specified by Fick's law, may become adapted in
organisms but might require some design compromise, i.e. which terms might not be as big as they could
be because they might cause organismal damage (check all that apply)? the diffusion coefficient the
surface area the diffusion distance the difference in pressure
Answer:
the surface area the diffusion distance the difference in pressure
Question:
3. Some of the challenges for gas exchange in aquatic single celled organisms include: the surface area/
volume ratio the diffusion distance the concentration of oxygen the size of membrane
Answer:
the concentration of oxygen
Question:
4. Match each of the axes of diversity with how they affect the evolution of gas exchange in organisms.
Phylogeny Metabolic rate Scaling Medium
affecting amount of oxygen available affecting amount of gas needed constraining what genes/structures
are available affecting surface area available for the volume
Answer:
Phylogeny constraining what genes/structures are available Metabolic rate affecting amount of gas needed
Scaling affecting surface area available for the volume Medium affecting amount of oxygen available
Question:
5. What is the role of stomates in a plant gas exchange system? providing a waxy cuticle to prevent
evaporation providing an open pathway for water loss providing a regulated pathway for CO2 influx
providing surface area for oxygen diffusion out of the guard cells
Answer:
providing a regulated pathway for CO2 influx
,Question:
6. Crabs utilize gills on land and in the water. What structural modifications does that likely require?
the use of stomates to let in oxygen some internal structure to keep gills from collapsing in air a strong
carapace to protect the appendages long antennae to sense which medium they are in
Answer:
some internal structure to keep gills from collapsing in air
Question:
7. Male fiddler crabs claw length (Y) grows much larger in proportion to their body length (X) as they get
increase in size, resulting in giant claws for the large males. What is true about the scaling exponent (b) in
the scaling equation describing claw length vs body length as they grow?
it is isometric, b= 1 it is positively isometric, b > 1 it is isometric, b = 2 it is negatively isometric, b < 1
Answer:
it is positively isometric, b > 1
Question:
8. What would you expect the scaling coefficient (b) to be when comparing the growth of an organisms
surface area (Y) when compared to its mass (X) if it is scaling isometrically?
b = 3/2 b = 2/3 b =1 b = 3
Answer:
b = 2/3
Question:
9. Match the organism on the left with its type of lung breathing for inhalation on the right bird mammal
frog (amphibian) bony fish ventilator
negative pressure breathing positive pressure breathing negative pressure breathing positive pressure
breathing positive pressure breathing
Answer:
bird negative pressure breathing mammal negative pressure breathing frog (amphibian) positive pressure
breathing bony fish positive pressure breathing ventilator positive pressure breathing
Question:
10. What makes a mammalian lung less ideal than a bird lung (select all that apply)? the mammalian lung
has unidirectional flow the mammalian lung has bidirectional flow the mammalian lung has uniform
(mixed) pool gas exchange the mammalian lung has countercurrent gas exchange
Answer:
the mammalian lung has bidirectional flow the mammalian lung has uniform (mixed) pool gas exchange
Question:
11. The system components of a circulatory system include an energy source, a pump, ductwork,
regulators, valves and fluids. Match the component in plants with the corresponding component in
animals.
Pacemaker Heart Blood Blood vessels
Water + solutes Stomates Xylem Water potential
, Answer:
Pacemaker Stomates
Heart Water potential
Blood Water + solutes
Blood vessels Xylem
Question:
12. Water potential contributes to the movement of water. Select all of the correction statements below.
water moves to higher solute concentration water moves to lower solute concetration water moves to
higher pressure water moves to lower pressure
Answer:
water moves to higher solute concentration water moves to lower pressure
Question:
13. True/False: Plants do not generate much pressure difference between the leaf air space and inside of the
leaf.
Answer:
False
Question:
14. We spent a lot of time comparing the circulatory systems of trees and animals like a giraffe. We
concluded that trees have a high pressure pump that drives a [flow] flow rate as a result of the [resist]
xylem.
Answer:
high pressure
Question:
15. Initially, plaque build up in arteries will only occlude a small fraction of the flow. If the artery diameter
is only 90% of normal (reduced by 10%) , how much will the flow rate be compared to normal? 90% 72%
65% 30%
Answer:
65%
Question:
16. Match the organism to the style of circulatory system they utilize.
oak tree human grasshopper annelid worm sponge
"open" closed system flow through open system flow through open system closed system closed system
Answer:
oak tree flow through open system human closed system grasshopper "open" closed system annelid worm
closed system sponge flow through open system
Question:
17. If the concentration at equilibrium of oxygen in the air with water at room temperature is .27mM, what
will happen when a can of water with .5 mM concentration of oxygen is exposed to room temperature air?
Oxygen will dissolve into the water Oxygen will be released from the water No change in oxygen
Answer:
Oxygen will be released from the water
GAE UPDATED ACTUAL QUESTIONS AND CORRECT
ANSWERS
Question:
1. Multicellular terrestrial organisms use a gas exchange system coupled to circulatory system. There are
several steps required to get oxygen from the air to the tissues in the body that need it. Pick the correct
answers to complete the sentence describing these steps: Animals fulfill their oxygen needs by having
oxygen move by------- to the lungs, by ------ into the blood stream, by ----- to an organ in the body, and by
-----into the cells of that tissue.
Answer:
Answer 1:bulk flow Answer 2:diffusion Answer 3:bulk flow Answer 4:diffusion
Question:
2. Gas exchange systems utilize diffusion and the diffusion rate can be described by Fick's law: In trying to
maximize the diffusion rate, what aspects of the system, as specified by Fick's law, may become adapted in
organisms but might require some design compromise, i.e. which terms might not be as big as they could
be because they might cause organismal damage (check all that apply)? the diffusion coefficient the
surface area the diffusion distance the difference in pressure
Answer:
the surface area the diffusion distance the difference in pressure
Question:
3. Some of the challenges for gas exchange in aquatic single celled organisms include: the surface area/
volume ratio the diffusion distance the concentration of oxygen the size of membrane
Answer:
the concentration of oxygen
Question:
4. Match each of the axes of diversity with how they affect the evolution of gas exchange in organisms.
Phylogeny Metabolic rate Scaling Medium
affecting amount of oxygen available affecting amount of gas needed constraining what genes/structures
are available affecting surface area available for the volume
Answer:
Phylogeny constraining what genes/structures are available Metabolic rate affecting amount of gas needed
Scaling affecting surface area available for the volume Medium affecting amount of oxygen available
Question:
5. What is the role of stomates in a plant gas exchange system? providing a waxy cuticle to prevent
evaporation providing an open pathway for water loss providing a regulated pathway for CO2 influx
providing surface area for oxygen diffusion out of the guard cells
Answer:
providing a regulated pathway for CO2 influx
,Question:
6. Crabs utilize gills on land and in the water. What structural modifications does that likely require?
the use of stomates to let in oxygen some internal structure to keep gills from collapsing in air a strong
carapace to protect the appendages long antennae to sense which medium they are in
Answer:
some internal structure to keep gills from collapsing in air
Question:
7. Male fiddler crabs claw length (Y) grows much larger in proportion to their body length (X) as they get
increase in size, resulting in giant claws for the large males. What is true about the scaling exponent (b) in
the scaling equation describing claw length vs body length as they grow?
it is isometric, b= 1 it is positively isometric, b > 1 it is isometric, b = 2 it is negatively isometric, b < 1
Answer:
it is positively isometric, b > 1
Question:
8. What would you expect the scaling coefficient (b) to be when comparing the growth of an organisms
surface area (Y) when compared to its mass (X) if it is scaling isometrically?
b = 3/2 b = 2/3 b =1 b = 3
Answer:
b = 2/3
Question:
9. Match the organism on the left with its type of lung breathing for inhalation on the right bird mammal
frog (amphibian) bony fish ventilator
negative pressure breathing positive pressure breathing negative pressure breathing positive pressure
breathing positive pressure breathing
Answer:
bird negative pressure breathing mammal negative pressure breathing frog (amphibian) positive pressure
breathing bony fish positive pressure breathing ventilator positive pressure breathing
Question:
10. What makes a mammalian lung less ideal than a bird lung (select all that apply)? the mammalian lung
has unidirectional flow the mammalian lung has bidirectional flow the mammalian lung has uniform
(mixed) pool gas exchange the mammalian lung has countercurrent gas exchange
Answer:
the mammalian lung has bidirectional flow the mammalian lung has uniform (mixed) pool gas exchange
Question:
11. The system components of a circulatory system include an energy source, a pump, ductwork,
regulators, valves and fluids. Match the component in plants with the corresponding component in
animals.
Pacemaker Heart Blood Blood vessels
Water + solutes Stomates Xylem Water potential
, Answer:
Pacemaker Stomates
Heart Water potential
Blood Water + solutes
Blood vessels Xylem
Question:
12. Water potential contributes to the movement of water. Select all of the correction statements below.
water moves to higher solute concentration water moves to lower solute concetration water moves to
higher pressure water moves to lower pressure
Answer:
water moves to higher solute concentration water moves to lower pressure
Question:
13. True/False: Plants do not generate much pressure difference between the leaf air space and inside of the
leaf.
Answer:
False
Question:
14. We spent a lot of time comparing the circulatory systems of trees and animals like a giraffe. We
concluded that trees have a high pressure pump that drives a [flow] flow rate as a result of the [resist]
xylem.
Answer:
high pressure
Question:
15. Initially, plaque build up in arteries will only occlude a small fraction of the flow. If the artery diameter
is only 90% of normal (reduced by 10%) , how much will the flow rate be compared to normal? 90% 72%
65% 30%
Answer:
65%
Question:
16. Match the organism to the style of circulatory system they utilize.
oak tree human grasshopper annelid worm sponge
"open" closed system flow through open system flow through open system closed system closed system
Answer:
oak tree flow through open system human closed system grasshopper "open" closed system annelid worm
closed system sponge flow through open system
Question:
17. If the concentration at equilibrium of oxygen in the air with water at room temperature is .27mM, what
will happen when a can of water with .5 mM concentration of oxygen is exposed to room temperature air?
Oxygen will dissolve into the water Oxygen will be released from the water No change in oxygen
Answer:
Oxygen will be released from the water
