Which Statement Best Relates Why These Animals Have So Much Blubber?

Photos.com

Animals take some amazing adaptations that assistance them live in even the most hostile environments. Consider camels, for instance. They can thrive in some of the hottest and driest places on Globe. Their legs don't get burned when they kneel on hot sand due to thick leathery patches on their knees. They tin survive for an entire week without water but, at the same time, they can drinkable 32 gallons of h2o at once. Their body temperature ranges from 93 °F to 107 °F, and so they don't need to sweat very often and tin conserve water this way. The spongy bones in their noses absorb any excess moisture to go on every drop of h2o in, and then the air they breathe out is dry air. In addition to camels, other animals' adaptations are equally remarkable. How do they do it? Chemical science helps!

Warm-Blooded or Common cold-Blooded?

The nigh of import accommodation is how animals regulate their trunk temperature. Animals can be either warm-blooded or cold-blooded.

Warm-blooded animals, which are more often than not birds and mammals, need to maintain a relatively constant body temperature or they would suffer dire consequences. It doesn't thing what the outside temperature is—they must maintain the same internal temperature. For united states of america, the normally accepted boilerplate body temperature is 98.6 °F (even though it may vary amongst individuals). Most other mammals range from 97 °F to 103 °F; birds accept an boilerplate body temperature of 105 °F.

Cold-blooded animals practise not maintain a constant body temperature. They get their heat from the outside environment, then their body temperature fluctuates, based on external temperatures. If it is 50 °F outside, their trunk temperature volition eventually drop to 50 °F, also. If information technology rises to 100 °F, their body temperature will reach 100 °F. Virtually of the rest of the animal kingdom—except birds and mammals—are common cold-blooded.

In nearly instances, the size and shape of an organism dictate whether it will exist warm-blooded or cold-blooded. Recollect 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 accept either an elongated or a flat shape. If y'all look at a typical fish, their bodies tend to be flat when viewed caput-on from the front. Snakes, lizards, and worms tend to be long and slender. These shapes ensure they can heat up and absurd downwardly rapidly.

Within a given species, animals tend to exist larger in colder climates and smaller in warmer climates, an observation known as Bergmann'southward rule. For case, whitetail deer in the southern part of the U.s. tend to accept a smaller torso 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: Equally the volume of an object decreases, the ratio of its surface expanse to its volume increases. In other words, the smaller an beast is, the college the surface area-to-volume ratio. These animals lose heat relatively quickly and cool downward faster, so they are more probable to be plant in warmer climates. Larger animals, on the other hand, take lower expanse-to-book ratios and lose heat more slowly, so and they are more probable to be found in colder climates.

Generating Energy

Warm-blooded animals crave a lot of energy to maintain a abiding body temperature. Mammals and birds crave much more nutrient and energy than do common 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 oestrus they produce is proportional to their mass. This means that larger warm-blooded animals can generate more oestrus than they lose and they can keep their body temperatures stable more easily. Smaller warm-blooded animals lose estrus more rapidly. And then, information technology is easier to stay warm past being larger. Warm-blooded animals cannot be too pocket-size; otherwise, they will lose heat faster than they can produce it.

This energy produced by warm-blooded animals more often than not comes from nutrient. Nutrient represents stored chemical energy (potential free energy), which is converted into other forms of energy within the body when the food is metabolized. Metabolism refers to the all of a torso'south chemical reactions.

The metabolism of food inside the torso is often referred to as internal combustion, since the same byproducts are generated as during a typical combustion reaction—carbon dioxide and h2o. And similar combustion reactions, metabolic reactions tend to exist exothermic, producing heat.

For a warm-blooded animal, food is not just a luxury—it is a matter of life and death. If food is not available for energy, the torso'due south fatty is burned. Once fat reserves are used up, death is imminent if a nutrient source is not found. The smaller the warm-blooded creature, the more than information technology must eat—relative to its trunk size—to proceed its internal furnace stoked. That'south why most songbirds wing south for the winter.

These turtles just walked out of a pool of absurd water.

NASA/JPL-CALTECH

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 surround. Information technology is common to encounter turtles basking in the sunday on rocks and logs. They are not trying to get a suntan, only rather are revving upwards their metabolism. The sunday gives them an energy boost. Muscle activity in cold-blooded animals depends on chemical reactions, which run quickly when it is hot and slowly when it is common cold (because the reacting molecules move faster when temperature increases).

Some reptiles, such as the python, can get a year without eating, because they do not utilise food to produce trunk oestrus. And if they lie still, they use petty energy, then they tin afford to eat lilliputian.

Cold-blooded animals have a disadvantage compared to warm-blooded animals: There is a sure temperature below which their metabolism simply won't work. The reason is that all chemical reactions slow downwardly as the temperature is lowered, so at low temperatures, all the chemical reactions in an organism slow down.

Y'all may notice that few cold-blooded animals are active in the winter, and the further north you go, the rarer they become. By contrast, warm-blooded animals are present in a wider variety of environments and for a longer part of the year than cold-blooded animals.

Hibernation

For warm-blooded animals that don't migrate, one manner to survive the winter is to slumber through information technology. Hibernation is a great strategy that enables animals to conserve energy when food is scarce. During hibernation, body temperature drops, breathing and center rate slows, and well-nigh of the body's metabolic functions are put on hold in a state of quasi-suspended animation.

It is nearly as if the warm-blooded creature becomes common cold-blooded, as its torso temperature drops considerably. But they are still alive, and they live off their fat reserves. Hibernation for extended periods of time is only accomplished by those animals that tin store a groovy deal of body fat, such as bears, groundhogs, and chipmunks. A black bear loses 15%–xxx% of its weight while hibernating.

Cold-blooded animals hibernate, too. Just they need to store less fat than warm-blooded animals because they require less energy. Turtles and frogs bury themselves in mud nether lakes and ponds for up to six months at a fourth dimension, and for all practical purposes, they appear dead. There are no external signs of life.

When many cold-blooded animals hide, something interesting happens at the cellular level. The fluid around the cells, but non in the cells, is frozen solid. As h2o freezes outside the cell, water from inside the jail cell is drawn out through osmosis. Osmosis is a procedure in which water moves across a semipermeable membrane—in this instance, the prison cell membrane—from an area of depression solute concentration to an area of high solute concentration.

As water freezes exterior of the cell, the solute concentration increases, because the quantity of liquid water decreases while the amount of solute stays the same. As a issue, water flows out of the prison cell to equalize the concentrated solution outside of the cell (Fig. 2).

At the same time water is leaving the cells, glucose migrates into the cells in copious amounts. By removing water and calculation glucose, the concentration of dissolved solute within the cell increases—a lot. The glucose acts every bit a natural antifreeze, equally whatever solute will lower the freezing point of a given solvent—in this instance, water. The presence of high concentrations of solutes in the cells allows animals such as frogs to hibernate at temperatures below freezing and nonetheless survive. While the water around the cells is frozen, the h2o in the cells is not. If water within a cell were to freeze, the cell membrane would be ruptured, killing the cell.

ISTOCK

Keeping Warm

When it is cold outside, you put on more clothes. Your winter coat does non go on out the cold, just rather keeps in the heat. (Common cold itself doesn't exist—information technology is simply the absenteeism of heat; run across the article titled "Why Cold Doesn't Exist," on p. 10.) Birds and mammals also rely on insulation to prevent heat loss. The about effective insulation traps air, since air is one of the all-time insulators. Wool tends to be warm because its fibers are curled, effectively trapping air and keeping you lot (and sheep) warm. Birds fluff up their feathers when they want to stay warm, since fluffing introduces air.

For mammals without pilus, insulation is accomplished by blubber, a thick layer of fat tissue which helps to insulate an animal'due south torso because fat does non transfer estrus every bit well equally muscle and skin. This blubber may be two feet thick in some whales! Whales, tuna, dolphins, and other warm-blooded marine animals too rely on another ingenious method to conserve rut. To foreclose excessive estrus loss from extremities such as fins and flippers—which are non well insulated—aquatic animals rely on a "countercurrent oestrus-substitution method," in which the arteries that carry warm blood away from the heart are positioned directly against the veins that behave absurd blood to the centre. So, the warmer blood leaving the heart through the arteries warms the cooler blood entering the heart through the veins.

In contrast to birds and mammals, lizards, frogs, snakes, and other cold-blooded animals do not need insulation—it would only boring down estrus transfer into their bodies.

Shutterstock

Keeping Cool

When you lot get hot, what'south the start affair that happens? You showtime to sweat. The average adult has three million sweat glands. It's not the sweating that cools you, merely rather the evaporation of this sweat. Evaporation is an endothermic phase change, pregnant it must absorb free energy to occur. This free energy is drawn from your trunk, making yous cooler.

Photos.com

Anytime you lose energy, your body will feel cool. Evaporation requires free energy because forces of allure betwixt water molecules—called intermolecular forces—need to be broken when h2o goes from a liquid to a gas. In liquid water, the molecules are shut together and are attracted to ane another. Evaporation requires free energy because the intermolecular forces of allure betwixt water molecules in the liquid stage must be overcome when water goes from a liquid to a gas. The energy that goes into overcoming these attractive forces comes from your body.

Practice animals sweat?  Most don't, but some exercise. Dogs sweat mainly between the pads on the bottom of their paws. One notable exception is the American hairless terrier, which has sweat glands all over its body, illustrating the fact that fur tends to inhibit sweating considering if the sweat can't evaporate information technology doesn't help in the cooling process.

Cats not only accept sweat glands on the pads of their feet, but also on their tongues! When a cat licks itself, it may non be just to keep clean, but it could also exist to cool itself as the saliva on their fur evaporates. Kangaroos will lick their forearms for the same reason.

Kangaroos go along cool by licking their forearms.

Shutterstock

The key to surviving in hot climates is not but to continue your torso from overheating but as well to prevent h2o loss. Animals that are adjusted to desert life are not heavy sweaters—because water is scarce, they cannot beget to lose information technology past sweating. Besides, a corking deal of water is lost through breathing out, and then desert animals expel dry out air, reabsorbing the water in their jiff before information technology has a hazard to exist expelled.

The ability of animals to suit to extreme environments is quite remarkable. Whether information technology is in the freezing corners of Siberia or the sizzling hot desert of the Sahara, animals ever find ways to survive, and how they practise it will never cease to amaze united states of america!

Brian Rohrig teaches chemical science at Metro Early on College High Schoolhouse in Columbus, Ohio. His most contempo ChemMatters article, "Not Milk? Living with Lactose Intolerance," appeared in the Apr 2013 issue.

Source: https://www.acs.org/content/acs/en/education/resources/highschool/chemmatters/past-issues/archive-2013-2014/animal-survival-in-extreme-temperatures.html

Posted by: brookscreter1959.blogspot.com

Share this post