in case of lizard when it loses it's tail or it's body part it grows after a short period of time..?
364424
Most lizards have a characteristic called autotomy: they can lose a part of their tail (usually at times of danger from predators) as a defense mechanism and it grows back (however, the regenerated structure is not exactly the same as the original tail). They cannot grow other body parts back. \nThe ability to regenerate is present in most "lower" (as in having simpler organization) animals, but also in some vertebrates such as fish and amphibians. The acquisition or loss of this ability has to do with the evolutionary paths of each type of organism and thus your question does not have a simple answer. At a macromolecular/genetic level, we lack some genes (or they're inactivated) that are necessary for regeneration to occur.\nSome of these genes have been identified in animals that have regenerative ability:\nhttp://pda.physorg.com/lofi-news-genes-planarian-alvarado_3953.html
563808
Yes, hair on the rest of your body also grows.\n\nEach hair, no matter where it is on your body, head, leg, face or inside your ear, is programmed to grow to a certain length, then stop, live so long, and fall out. \n\nHow about facial hair? It obviously grows constantly, or guys would not have to shave it off all the time. Mustaches, beards and eyebrow hairs fall out when they reach maturity, and if you don't trim it, will grow to the same length each time before falling out. \n\nEach of your hundreds of thousands of hairs on your head are on rotating growth cycles, with about a 100 hairs falling off every day.\n\nEach one is on its own random cycle so you don't lose them all on one day. Your whole body works like that. \n\nToday, several million of your bloods cells died, and today the same amount were born. Everything dies and regenerates. Your stomach cells dissolve and are replaced every few days, bone cells take much longer. Every 7 years, there is not one cell in your body that is left from 7 years ago.\n\nSo every 7 years, you are totally new. That's why when someone asks how old I am, I always say 7 years old. \n\nWe are like a wave in the ocean...it is not a moving hunk of water in the shape of a wave moving as a unit from ocean to shore. It is a moving pattern, made of NEW water every few feet. The wave, like your body, just retains the pattern of you, not the specific stuff of which you are made.
350452
no alligators do not show regeneration.\nanimals like starfish do,when they are cut they regenerate that part of the body and it grows back.\nhowever alligators do not have this property
627783
It doesn't-- it's an old myth. As the drying skin recedes from the bone, more nail is exposed giving it the appearance of growth. As for the hair, I guess it was just an assumption since it still looks normal after the skin shrivels.
935334
You friend is wrong. Some worms continue to live as two worms if you cut them up, or the living part grows again.\n\nBut if you cut up a snake, you break its backbone. No creature survives a cut up back bone. Yes, it dies.
1017954
I can show you a website that's a little technical, but should help.\n\nThe basic answer is, not really.  Most lizards are designed not to waste water, so they don't "pee" in the same sense a dog or a cat does.
1148004
fish will only grow as big as comfortable for the space they live in, if they are in a very small pond they'll stay small for years but, the minute they are in a big body of water they will get huge fast.
582572
I'm gonna assume that the pituitary gland in you brain regulates the hair growth and stops sending the hormones necessary for it to grow once it realizes how long it is.
582757
Mammals have determinate growth.  This means that they will reach a certain size and stop growing.  Reptiles and many other vertebrates have indeterminate growth.  Although growth slows down with age, it continues throughout their lives.\n\nThe story of the evolution of determinate growth really takes place in the ancestors of all mammals.  So the human story is really just a throwback to that.  It's possible that it may relate to the evolution of endothermy (warm-bloodedness) and related changes involving higher metabolism and fueling that metabolism.\n\nMammals are a bit more precise a machine than reptiles in many ways.  We have complex teeth that need to fit together properly if they are to work.  The molars, premolars, canines, and incisors are quite a bit more advanced than the pointy teeth of reptiles.  With a final set of permanent teeth (particularly molars and premolars), chewing happens efficiently only when things fit together properly.  Evolution plays an important role in this, but it would be very difficult to grow in a set of teeth that would precisely fit a mouth only if that mouth were to consistently increase in size.  Instead, we are set up to get that final molar right as we stop growing.\n\n4 chambered hearts, the association between basal metabolic rate and surface area to volume ratio, lung capacity, ossification of bones, and other factors are all fine-tuned by evolution to match a general body size and increase the fitness of mammals.  An interesting aside is that when you have determinate growth, you can change body size fairly easily across evolutionary time by simply changing when you stop growing in addition to how fast you grow.  That's why you can get closely related mammals that vary considerably in size.
397831
It depends on the type of rattlesnake, how well it has been eating, and on the individual characteristics of that particular snake.\n\nRattlesnakes add a "button" to their rattle each time they shed their skin.  Rattlesnakes, as all snakes, shed their skin after they grow a certain amount.  The rate of growth is not constant throughout their life.  They grow very fast from birth, but then slow down as they reach maturity.  If they live in an area where food is scarce, or difficult to catch, they will not grow as fast as one for whom food is plentiful and easily captured.\n\nBecause of the unconstant growth rate, counting the rattles is not an effective method to predict a snake's size, nor it's age.  Also, rattles can break, partially or completely.  An island off of South America boasts a population of rattlesnakes that don't have any rattles at all.  They have evolved to be brittle, and break off immediately after each shed.  This trait was selected, because the main prey item on this island isn't rodents, but birds, which must be hunted in the trees where they live.  Can you imagine trying to sneak up on an alert, very fast-reacting bird when your rattle gives you away everytime the wind moves the branch you're on?
378971
I have found reliable citations at Fishbase of 29 years, and others cite 17-15 years (for the species Chimaera monstrosa). This is not unexpected, given that these fishes, like all chondrichthyans, grow relatively slowly and take several years to become sexually mature. These are very long-lived animals.\n\nhttp://www.fishbase.org/PopDyn/PopCharList.php?ID=2503&GenusName=Chimaera&SpeciesName=monstrosa&fc=25
566806
"Variation in Diet\nAlthough helodermatid lizards are specialists on vertebrate nests, they appear to be generalists regarding the kinds of nests they exploit.\nA diversity of prey species and sizes has been documented in the diets of Beaded Lizards and Gila Monsters.  Although some of these prey items are relatively small lizard and snake eggs, others, such as quail nets and nestling rabbits, are large and provice substantial energy gains per food item.  A meal of cottontail nestlings can weigh over one-third the mass of an adult Gila Monster and provide nearly one-third of a Gila Monster's annual energy budget (Beck 1990; chap. 4).  Along with these energy benefits come the basic mechanical challenges of swallowing a large meal or a hard-shelled egg.  Egg-eating snakes of the genera Dasypeltis and Elachistodon have modifications of the jaws, teeth, skull, and even the vertebrae that allow them to efficiently swallow eggs (Gans 1974). Although helodermatid lizards are not so specialized, they do appear to use a few "tricks" to make eggs go down easier.\n\nFeeding Behavior\nHow Prey are Eaten\nHerrel et al. (1997) describe five stages of H. horridum eating quail eggs: approach, pierce, uptake, crush, and swallow.  A Beaded Lizard first locates the egg, both visually and by tongue-flicking, then rises on its front legs and bites the egg with its front teeth, piercing it without breaking it.  The piercing bite may be repeated several times, yet the egg remains intact.  During the uptake phase, the lizard maneuvers its jaws around the egg by either flicking the egg in the air or pushing it against an object or the ground.  The tongue aids in maneuvering the food object into the oral cavity, but the primary force used during the uptake phase is inertia generated by movements of the lizard's head, neck, and jaws.  Such a feeding mechanism, called inertial feeding, contrasts with lingual feeding mechanisms (using the tongue to deliver food objects into the mouth) shown by most other lizards (Gans 1969)..."\n\nNot information about the actual digestive system, but information about diet and feeding.  This is an excerpt from Daniel D. Beck's new book.\n\nLet me know if you want a photo of a Gila Monster!
621072
The lizard is fed nutrients through a connection with the yolk on the egg. It is given air through small holes in the egg shell. The shell also protects the lizard from outside disease and physical harm.
974358
lizards can regenerate tails\nnewts and salamanders can regenerate\n\nPlanarians are flat worms. If cut into pieces, each piece can grow into a new worm.\n\nSea cucumbers have bodies that can grow to be three feet long. If cut into pieces, each one can become a new sea cucumber.\n\nSharks continually replace lost teeth. A shark may grow 24,000 teeth in a lifetime.\n\nSpiders can regrow missing legs or parts of legs.\n\nStarfish that lose arms can grow new ones; sometimes an entire animal can grow from a single lost arm.
780735
GECko - a lizard like animal
47595
There have been occasional cases where children have been born with a tail. Check out the link below:
836985
Dead stuff doesn't grow. Instead, what is perceived as "growth" is acually the surrounding tissues receding, or shrinking, as a result of moisture loss from the once living surrounding tissue. Hair and nails are mostly protein (keratin) and contain very little moisture (in comparison to skin cells) and thus don't shrink.