Exam 3 Practice Flashcards
(77 cards)
Define adaptation and give an example using any animal
An adaptation is any heritable trait that increases the fitness of an individual with that trait, compared with individuals without that trait, in a particular environment. An example is the big ears of African elephants that help them regulate body temperature.
Define acclimatization and give an example using any animal
Acclimatization is a change in an individuals phenotype that occurs in response to a change in natural environmental conditions. Humans who tan count as acclimatization (because their skin color will soon revert to its normal color if out of the sun)
What are the trade-offs that marine and freshwater fish face in terms of their reproductive strategies?
Because fish are ectothermic poikilotherms (generally), they do not have to dedicate a lot of their energy to warming themselves using metabolism. They can therefore use this energy for reproduction, but they may have more mortalities (a lot of eggs) or less offspring (large eggs that survive longer)
Why are surface area and volume important to understand animal metabolism?
The amount of surface area available is important to the diffusion of different things (oxygen, nutrients, etc) into the cells. Surface area influences the rate while volume influences the rate at which nutrients are used and heat and waste are produced
How do the surface area and volume of a spherical animal change with increasing size?
Surface area increases as a function of its linear dimension squared while volume increases as a function of its linear dimension cubed, therefore volume increases at a faster rate than surface area especially for larger numbers
You are working with the amphibian Xenopus sp. in your lab. Your professor asks you to measure the metabolic rate of Xenopus. Which metabolic rate would you measure and how? Describe at least two ways you could measure it
Because this amphibian is an ectotherm, standard metabolic rate (SMR) is the appropriate measure to use. You can measure metabolism using either O2 or CO2, though O2 is best
Draw a diagram that illustrates the homeostatic feedback of a human in the presence of heat with its different components. What are the 3 main features of homeostasis systems?
(Draw a picture of a person sweating. First body temperature increases. The brain detects this change. A person Starts sweating). The three features are the sensor, which senses a variable in the internal or external environment, then the integrator, which compares this variable to the set point to determine if action is necessary, and finally the effector, which is any structure that helps restore the condition that is monitored by the system
How does a non-furred animal control body temperature compared to a furred animal?
Furred animals have insulation due to their fur, so the heat their bodies generate is contained in the cold but they can’t sweat like non-furred animals in the heat. Both generally may seek shade or cool surfaces to relieve heat but conduction will be less effective for the furred animals
What are the trade-offs of endothermy and ectothermy?
For endothermy, there is a lot of energy directed towards maintaining body heat that it cannot be used for other factors such as reproduction. However, they are better able to occupy cold regions and can move at night easily. Ectothermy is the opposite – their muscle activity and digestion slow as the temperature drops
Explain the physiological strategy that penguins or polar bears have in their appendages to keep body temperature warm
The strategy is similar to that seen in the tongues of whales, using concurrent heat exchange to minimize heat loss to the environment. Cold blood moves towards the body as warm blood moves away
The Q10 value for a snake metabolic rate is consistently 2.3 across a range between 8 and 35 degrees celsius. The metabolic rate of this species at 10 degrees is 0.1 ml of oxygen/gr/h. What is the metabolic rate of this animal at 30 degrees?
Q10 equation is: MR(t+10) / MRt (metabolic rate vs temperature). 2.3 = MR(20)/0.1. 2.30.1=MR(20). MR(20)=0.23. 2.3=MR(30)/0.23. 2,30.23=MR(30). MR(30)-0.529
Explain he statement “animals do very little work” in metabolic terms
Animals (especially large ones and those that are endothermic) need to consume a lot of food to get energy, but they are unable to utilize most of the energy for movement and such. Most is used for internal processes or is lost as heat
How did Lavoiser contribute to animal physiology?
He measured metabolic rate using the direct calorimeter
How many grams of water does an animal need to evaporate in order to get rid of 1080 calories?
Gramsofwater=
Calories to lose/Latentheatpergram
Gramsofwater = 1080 cal / 580 cal/g≈1.86
How is it possible some fish species can be heterotherms and some homeotherms? Give some examples of the two
There are fish in the sea for example that will maintain the same body temperature because, generally, the ocean’s temperature does not change. A fish living in a cold environment would also have to maintain the same temperature. Others, especially freshwater fishes, would be poikilothermic, instead
Would a rabbit species adapted to dessert environments use panting as a means to lose heat?
Because the rabbit is living in a desert environment, maintaining as much water as possible is crucial, which would not happen if it would use panting to lose heat. Their large ears would work similarly to those of African elephants to help lose heat. They may also burrow into the ground where it’s cooler
Using the Scholander diagram describe how endotherms maintain MR within the TNZ
Metabolic rate stays constant at BMR and heat is regulated
What is brown fat, what is it used for, and where can it be found in animals?
Brown fat is a special type of fat found in some animals used for heat production, especially in cold environments. Location varies but generally it is between the shoulder blades, around the neck, or around the kidneys
Explain why metabolic rates in ectotherms peak and then begin to decrease after optimal temperature
After the ‘peak’ of optimal temperature, destructive effects occur, especially structural damage
Why is it important to specify the temperature range when giving a Q10 value? Why will these ranges potentially be different for different organisms? How might you expect Q10 values to differ across the range of survivable temperatures for an ectotherm?
Q10 measures the affect of a 10 degree C rise in temperature as a proportion of the original rate, so it is important to specify the range because Q10 is not always constant. Values vary because each organism is different in thermal tolerance, metabolic specialization, and enzyme stability at different temperatures. For an ectotherm, at low temps Q10 is high, at optimal range it is moderate, and the upper limits it may drop or become undefined
What is the difference between Basal Metabolic Rate and Standard Metabolic Rate? Why is it important to differentiate between the two?
BMS is for endotherms at rest in a thermoneutral zone. SMR is for ectotherms at rest. These two types of organisms are drastically different, which is why it is important to distinguish between them before deciding which to use
What are deposit feeders? Give an example
These feeders swallow sediments and other types of deposited material rich in organic matter (examples include earthworms and sea cucumbers)
How is an incomplete digestive tract organized?
In an incomplete digestive tract, there is only one opening: the mouth. Food enters through the mouth and is passed into the gastrovascular cavity for digestion to take place. Once done, wastes are disposed of back through the mouth
What are two advantages of complete digestive tracts?
- Feeding does not have to be paused for waste disposal to occur. And the different chemical and physical processes occur independent of one another in their own confined space, allowing for a set sequence to be followed
