Allometry and Metabolic Scaling
On a per weight basis, do smaller or larger animals typically need more energy?
What is smaller animals.
This is a form of energy that depends on the number of atoms/molecules in an object and their speed, making it directly proportional to the amount of matter.
What is heat?
What is the term for the individual pressure exerted by a particular gas in a mixture of gases?
What is partial pressure
The movement of O2 and CO2 between an animal and its environment occurs across this.
What is a gas exchange membrane?
The lungs of frogs are classified as this, meaning they consist of a single open sac.
What is unicameral?
According to the allometric equation for metabolic rate (M = aW^b), what does the 'W' represent?
What is body weight.
While most mammals are endotherms that thermoregulate, provide an example of an endothermic group that does not always thermoregulate.
What is most hibernating mammals?
Compared to oxygen and nitrogen, this respiratory gas has a significantly higher solubility in water.
What is carbon dioxide (CO2)?
This type of gas exchange, found in fish gills, maintains a PO2 gradient between the medium and blood along the entire respiratory surface.
What is countercurrent gas exchange?
How do insects deliver oxygen directly to their metabolically active tissues, largely bypassing the need for a circulatory system for gas transport?
What is through a network of gas-filled tubes called trachea and tracheoles that open to the outside via spiracles
This constant in the allometric equation for RMR or BMR is not consistently the same across different animal groups.
What is 'a' (the scaling factor or y-intercept)?
The metabolic rate of a lizard abruptly transferred from a warmer to a colder environment initially shows this type of response.
What is an acute response (a drop in metabolic rate)
This gas is the final electron acceptor in cellular respiration, making its supply relatively urgent for animals with high metabolism.
What is oxygen (O2)?
In mammals, lizards, and amphibians, their lungs are ventilated in this manner, where the lungs can never be fully emptied.
What is tidally ventilated?
What is the term for fish, like tuna, that rely on their swimming motion to force water across their gills for ventilation?
What is ram ventilators?
The exponent 'b' in the non-weight-specific metabolic rate allometric equation is commonly found to be within this range for a wide array of animals.
What is 0.6 to 0.8 (or nearly universally 0.5 to 0.9)
What happens to a homeotherm's metabolic rate when the ambient temperature falls below its lower critical temperature (TNZ)?
What is its metabolic rate increases to increase body temperature/heat through metabolism
How do increases in water temperature and salinity affect the absorption coefficient (A) for gases like oxygen and nitrogen, and what does this mean for the solubility of these gases in water?
What is that A is inversely related to temperature and salinity, meaning that as temperature and salinity increase, the solubility of these gases decreases?
Describe how the contraction of the diaphragm muscle contributes to inhalation in mammals.
What is it expands the lung volume, creating a negative pressure within the lungs relative to the atmosphere, which causes air to flow into the lungs by suction
Stationary teleost fish, like a goldfish, maintain gill ventilation using these two pumping mechanisms.
What are both a buccal pressure pump and an opercular suction pump?
Explain why a plot of metabolic rate vs. body weight on a linear scale is curved.
What is because 'b' is not 1, indicating a non-proportional relationship, the exponent 'b' in M = aWb for non-weight-specific BMR is typically around 0.7
Explain how countercurrent heat exchange helps homeotherms in cold environments conserve body heat in their extremities.
What is warm arterial blood flowing towards the extremities passes in close proximity to cooler venous blood returning to the body core. Heat is transferred from the arteries to the veins, thus warming the returning blood and reducing heat loss from the extremitie
Explain the concept of the oxygen cascade in the context of oxygen transport from the atmosphere to the mitochondria.
What is the partial pressure of oxygen (PO2) progressively decreases with each step in the oxygen transport pathway, from the atmosphere to the lungs/gills, then to the blood, to the tissues, and finally to the mitochondria. This gradient of PO2 is essential for the passive diffusion of oxygen at each step
What advantage does the unidirectional airflow and cross-current gas exchange in bird lungs provide compared to the tidal airflow in mammalian lungs?
What is that it is energetically Inexpensive, most efficient because mostly fresh air enters the lungs (unlike mammals), and advantageous?
Reptiles with multicameral lungs fill them primarily using this pressure mechanism, unlike amphibian buccal pumping.
What is suction (negative pressure)?