Warm-blooded animals, which are mostly birds and mammals, need to maintain a relatively constant body temperature or they would suffer dire consequences. For us, the commonly accepted average body temperature is Cold-blooded animals do not maintain a constant body temperature.
They get their heat from the outside environment, so their body temperature fluctuates, based on external temperatures.
Most of the rest of the animal kingdom—except birds and mammals—are cold-blooded. In most instances, the size and shape of an organism dictate whether it will be warm-blooded or cold-blooded. Think about some large animals—elephants, whales, and walruses. Their volume is so large that relying on the outside environment to heat them up would be inefficient and would slow their response times, putting their survival at risk.
For that reason, nearly all large animals are warm-blooded. What about all the birds and mammals that are not large, such as mice and sparrows? The other factor—body shape—comes into play here. Small warm-blooded animals tend to have a rounded shape, which ensures that the interior of an organism stays warm the longest time possible. Most cold-blooded organisms have either an elongated or a flat shape.
If you look at a typical fish, their bodies tend to be flat when viewed head-on from the front. Snakes, lizards, and worms tend to be long and slender. These shapes ensure they can heat up and cool down rapidly. For example, whitetail deer in the southern part of the United States tend to have a smaller body size and less overall mass than whitetail deer in the far northern states. There are exceptions but, overall, this rule holds true, for the following reason: As the volume of an object decreases, the ratio of its surface area to its volume increases.
In other words, the smaller an animal is, the higher the surface area-to-volume ratio. These animals lose heat relatively quickly and cool down faster, so they are more likely to be found in warmer climates.
Larger animals, on the other hand, have lower surface area-to-volume ratios and lose heat more slowly, so and they are more likely to be found in colder climates. Warm-blooded animals require a lot of energy to maintain a constant body temperature.
Mammals and birds require much more food and energy than do cold-blooded animals of the same weight. This is because in warm-blooded animals, the heat they lose is proportional to the surface area of their bodies, while the heat they produce is proportional to their mass.
This means that larger warm-blooded animals can generate more heat than they lose and they can keep their body temperatures stable more easily. Smaller warm-blooded animals lose heat more quickly. So, it is easier to stay warm by being larger.
Warm-blooded animals cannot be too small; otherwise, they will lose heat faster than they can produce it. This energy produced by warm-blooded animals mostly comes from food. Food represents stored chemical energy potential energy , which is converted into other forms of energy within the body when the food is metabolized.
The metabolism of food within the body is often referred to as internal combustion, since the same byproducts are generated as during a typical combustion reaction—carbon dioxide and water. And like combustion reactions, metabolic reactions tend to be exothermic, producing heat. For a warm-blooded animal, food is not just a luxury—it is a matter of life and death.
Once fat reserves are used up, death is imminent if a food source is not found. The smaller the warm-blooded animal, the more it must eat—relative to its body size—to keep its internal furnace stoked. On the other hand, cold-blooded animals require less energy to survive than warm-blooded animals do, because much of the energy that drives their metabolism comes from their surroundings.
It is common to see turtles basking in the sun on rocks and logs. Related questions What are some examples of endothermic organisms? How does the hypothalamus regulate body temperature? What are some examples of torpor? What is the hypothalamus?
Are annelids endotherms or ectotherms? Are lizards endotherms or ectotherms? Are reptiles ectothermic or endothermic? How do endotherms stay warm? The activity will take approximately 10 minutes to prepare and includes minutes of learning time.
It is best suited for students in elementary school grades. Start by taking your Ziploc bags and turning one inside out. This is so you can zip them both together later. Now, take the bag that is not inside out and, with your spoon or spatula, put some of the vegetable shortening inside the bag.
Fill the bag a good bit. Take the second Ziploc bag and put your hand inside. Slip that bag inside the bag with the shortening in it. Zip the bags together tape them if needed so no water can get in.
Be sure to spread around the shortening all along both sides of sealed space created by the two bags. Set aside for a moment. Place your bare hand in your bowl of ice and water just long enough to get a good idea of how cold it feels.
Remove your hand and dry it. Amphibians warm up by moving into the sun or diving into warm water. They cool off by entering the shade. In cold weather, honeybees huddle together to retain heat. Bees and large moths build up heat before takeoff by contracting their flight muscles without moving their wings. In addition to behaviors, physiological adaptations help ectotherms regulate temperature. Diving reptiles conserve heat because their blood circulates inward toward the body core during a dive.
0コメント