BIO 361 MIDTERM 2 CAL POLY QUESTIONS
WITH 100%RATED ANSWERS 2024/2025 LATEST
UPDATED/GET A+
Why would we measure the heat produced by an animal as a way to quantify the
animal's energy metabolism? - It is hard to measure metabolism directly. The heat produced by
an animal can be done in the field
Inefficiencies from biosynthesis, maintenance and generation of external work all lead to heat
waste
What other ways are there to quantify energy metabolism? - Oxygen consumption
Food eaten/feces dropped
Why are these measurements a good approximation to the metabolic rate of an organism? -
Oxygen is used in the electron transport chain which is how mitochondria create ATP which
animals use for movement
Food is fuel for the metabolic rate
Heat waste is the byproduct of all energy consumed by an animal
When we measure the metabolic rate by quantifying the consumption of oxygen,
the heat produced per ml of oxygen depends on the food consumed. How different
is the heat produced by carbohydrates, lipids and proteins? - carbs> Lipids>proteins
carbs: 1.0
lipids: .71
proteins: .83
What does this mean for the usefulness of quantifying metabolism by measuring the
consumption of oxygen? - It is not perfectly accurate. However. protein/lipid/carb oxygen
consumption is much more precise than protein/lipid/carb carbon dioxide waste
How can we identify (at least make a good guess of) the type of food that the organism is fed? -
RER: Respiratory exchange ratio differs based on foodstuff consumed. Carbs = 1. Lipids = 0.71
Proteins = 0.83. Measure RER of an organism, and have an idea of what their diet consists of
What is the difference between a 'closed' and 'open' respiratory system? - Closed: two chambers
with liquid between. One has the animal and a CO2 absorbant. The change of the volume of gas
in the animals chamber os the oxygen used
Open: air flows through a chamber with an animal in it. Percent oxygen is measured pre and post
animal chamber. Subtract outgoing from incoming and adjust for the rate of airflow to get
oxygen used over time
What are the possible challenges for the organism when using a 'closed' system? - as the air
pressure in the jar decreases/oxygen content in jar decreases, the animal can get stressed &
, increase its respiration rate which can mess up the accuracy of measurements (increases
BMR/SMR), small space
What is "specific dynamic action"? SDA - Equals Heat Increment of Feeding (HIF)
When the metabolic rate goes up when an organism eats a meal
Why do physiologists that measure the basal or standard metabolic rate of organisms fast their
study animals for 24 h or longer before initiating the measurement? - The amount of food in the
system effects metabolism. When an animal eats, their metabolism spikes and then slowly
decreases. Along with their oxygen consumption So, depending on how long ago the organism
ate, would affect the metabolic rate. By fasting an organism, researchers can standardize for this.
Why do you think the metabolic rate (MR) of an organism goes up after a meal? Is this the case
for all organisms? Is the response more pronounced in some organisms and, if so, why? -
Because it takes energy to digest food and turn it into something useful for the organism
This is the case for all organisms
More prominent in organisms who go long periods of time without eating, sit and wait predators.
More prominent in larger animals? Small animals have to eat too often
Explain the difference between BMR, SMR, MMR and FMR and how they relate to each other
(e.g., MMR is about five times BMR or so). What are the pre-requisites for each of the
measurements of MR? - Basal Metabolic Rate (BMR):
-BMR is the metabolic rate of an endotherm/homeotherm (organism that regulates its internal
temperature) while it is: 1) in its thermoneutral zone, 2) fasting/in postabsorptive phase, & 3)
resting
-thermoneutral zone: temperature that animal is adapted to, moderate ambient temperature,
dependent on animal
Standard Metabolic Rate (SMR):
-SMR is the metabolic rate of an ectotherm (org. that doesn't regulate its internal temp) while it
is: 1) fasting/in postabsorptive phase, & 2) resting
-SMR is always stated for a given temperature, depends on temperature (i.e: organism's SMR at
20°C)
Maximum metabolic rate (MMR):
-the maximum metabolic rate that an animal can achieve for a brief period of time (aka
VO2max)
-often refers to max rate of AEROBIC metabolism
-may be measured during exercise, cold challenge (colder temp than animal is used to), or SDA
Field Metabolic rate (FMR):
-FMR is the average metabolic rate of a free-living animal going about its regular business in its
natural environment
-FMR varies but is often somewhere around 2.5/3.5x the BMR or SMR
-usually must be measured with indirect methods (i.e: doubly-labelled water, heart rate
telemetry; difficult)
-ecologically important measurement (why we do it even tho its difficult) because it determines
rate of resource consumption
WITH 100%RATED ANSWERS 2024/2025 LATEST
UPDATED/GET A+
Why would we measure the heat produced by an animal as a way to quantify the
animal's energy metabolism? - It is hard to measure metabolism directly. The heat produced by
an animal can be done in the field
Inefficiencies from biosynthesis, maintenance and generation of external work all lead to heat
waste
What other ways are there to quantify energy metabolism? - Oxygen consumption
Food eaten/feces dropped
Why are these measurements a good approximation to the metabolic rate of an organism? -
Oxygen is used in the electron transport chain which is how mitochondria create ATP which
animals use for movement
Food is fuel for the metabolic rate
Heat waste is the byproduct of all energy consumed by an animal
When we measure the metabolic rate by quantifying the consumption of oxygen,
the heat produced per ml of oxygen depends on the food consumed. How different
is the heat produced by carbohydrates, lipids and proteins? - carbs> Lipids>proteins
carbs: 1.0
lipids: .71
proteins: .83
What does this mean for the usefulness of quantifying metabolism by measuring the
consumption of oxygen? - It is not perfectly accurate. However. protein/lipid/carb oxygen
consumption is much more precise than protein/lipid/carb carbon dioxide waste
How can we identify (at least make a good guess of) the type of food that the organism is fed? -
RER: Respiratory exchange ratio differs based on foodstuff consumed. Carbs = 1. Lipids = 0.71
Proteins = 0.83. Measure RER of an organism, and have an idea of what their diet consists of
What is the difference between a 'closed' and 'open' respiratory system? - Closed: two chambers
with liquid between. One has the animal and a CO2 absorbant. The change of the volume of gas
in the animals chamber os the oxygen used
Open: air flows through a chamber with an animal in it. Percent oxygen is measured pre and post
animal chamber. Subtract outgoing from incoming and adjust for the rate of airflow to get
oxygen used over time
What are the possible challenges for the organism when using a 'closed' system? - as the air
pressure in the jar decreases/oxygen content in jar decreases, the animal can get stressed &
, increase its respiration rate which can mess up the accuracy of measurements (increases
BMR/SMR), small space
What is "specific dynamic action"? SDA - Equals Heat Increment of Feeding (HIF)
When the metabolic rate goes up when an organism eats a meal
Why do physiologists that measure the basal or standard metabolic rate of organisms fast their
study animals for 24 h or longer before initiating the measurement? - The amount of food in the
system effects metabolism. When an animal eats, their metabolism spikes and then slowly
decreases. Along with their oxygen consumption So, depending on how long ago the organism
ate, would affect the metabolic rate. By fasting an organism, researchers can standardize for this.
Why do you think the metabolic rate (MR) of an organism goes up after a meal? Is this the case
for all organisms? Is the response more pronounced in some organisms and, if so, why? -
Because it takes energy to digest food and turn it into something useful for the organism
This is the case for all organisms
More prominent in organisms who go long periods of time without eating, sit and wait predators.
More prominent in larger animals? Small animals have to eat too often
Explain the difference between BMR, SMR, MMR and FMR and how they relate to each other
(e.g., MMR is about five times BMR or so). What are the pre-requisites for each of the
measurements of MR? - Basal Metabolic Rate (BMR):
-BMR is the metabolic rate of an endotherm/homeotherm (organism that regulates its internal
temperature) while it is: 1) in its thermoneutral zone, 2) fasting/in postabsorptive phase, & 3)
resting
-thermoneutral zone: temperature that animal is adapted to, moderate ambient temperature,
dependent on animal
Standard Metabolic Rate (SMR):
-SMR is the metabolic rate of an ectotherm (org. that doesn't regulate its internal temp) while it
is: 1) fasting/in postabsorptive phase, & 2) resting
-SMR is always stated for a given temperature, depends on temperature (i.e: organism's SMR at
20°C)
Maximum metabolic rate (MMR):
-the maximum metabolic rate that an animal can achieve for a brief period of time (aka
VO2max)
-often refers to max rate of AEROBIC metabolism
-may be measured during exercise, cold challenge (colder temp than animal is used to), or SDA
Field Metabolic rate (FMR):
-FMR is the average metabolic rate of a free-living animal going about its regular business in its
natural environment
-FMR varies but is often somewhere around 2.5/3.5x the BMR or SMR
-usually must be measured with indirect methods (i.e: doubly-labelled water, heart rate
telemetry; difficult)
-ecologically important measurement (why we do it even tho its difficult) because it determines
rate of resource consumption
