Animals: Function of metabolism
Animals take in energy by eating food, and giving off waste. Their waste
may be undigested food particles, and exhaled gases. This entire process is
called "metabolism". We can divide animals into two major types of organisms
based on how they regulate their metabolism. Some animals regulate their
metabolism by keeping their body temperature the same as the environment.
We call these animals "ectotherms". Examples of ectotherms are fish, frogs, and
insects. Other animals regulate their metabolism by keeping their body
temperature different from their environment. We call these animals
endotherms". Examples of endotherms are birds, and mammals (including you!).
When an ectotherm gets warmer, its heart beats faster so it needs to eat
more. It also breathes faster so it needs more oxygen. When an endotherm gets
warmer it sweats (Think of what you do when you get hot!) or pants like a dog.
An endotherm eats less in order to keep cool (remember that food contains
energy, and more energy means more heat). The opposite reactions occur when
the environment cools down. Ectotherms breathe slower, and eat less.
Endotherms shiver (Again, what do you do when you get cold?) or fluff up their
fur or feathers. Endotherms will also eat more in order to have more energy to
keep them warm.
Today, we are going to learn how a goldfish, an ectotherm, reacts to its
environment by changing water temperature. As the fish gets warmer, its body
temperature should get warmer, so it should breathe faster. As the fish gets
cooler, its body temperature should get slower, so it should breathe slower.
Methods:
* Place the goldfish and aged water in a jar.
* Let the fish calm down for a few minutes, and record water temperature.
* Count the number of breaths the fish makes by counting the number of
times it opens its mouth, or the number of times its operculum moves. Count for an entire minute and record this. Repeat two more times and average.
* Carefully add warm water to the jar, and record the water temperature.
* Let the fish calm down for a few minutes, then count and record the
number of breaths in one minute. Take two more trials and average.
* Carefully add ice to the jar, and record the water temperature. Make sure
to only add enough ice to change the temperature. Do not fill the jar with ice.
* Let the fish calm down for a few minutes, then count and record the
number of breaths in one minute. Take two more trials and average.
Goldfish condtions (C) / Trial 1 / Trial 2 / Trial 3 / AverageGraph your results.
Make a conclusion about the effect of temperature on respiration for goldfish. Use your data to support your conclusion.