What is the process of metamorphosis for toads?  When do they start breathing air?
535356
for short: egg-embryo-tadpole-froglet-frog.\n\nthey start breathing air as soon as they hatched from eggs. the tadpoles breathe with external gills, like salamanders. when they changed into froglet, the gills will start to disappear because at the same time, their external lungs will be developed enough to help them breathe.
733236
to quote any help?: "frogs work ok, as long as they are not solid"... what the hell?!? how many semi solid frogs you come across lately??? you are not any help, any help?... where you from? another oxygen thief...
615122
Both are common names and it's not easy to equal them with actual systematic groups. \nThe name "toad" is usually applied to the species of genus Bufo (family Bufonidae); these are animals with well keratinized, "warty", rugose skin, cephalic ridges (formed by the head bones), and large parotoid (venom) glands, situated approximately behind the eye and the tympanum. Toads lack teeth and are walkers rather than leapers (their hindlimbs are not much larger than their forelimbs). \nBear in mind that not all the members of family Bufonidae have these characteristics.\n\nThe name "frog" is applied to... well, almost any other Anuran, therefore it's difficult to define it. We usually think of frogs as animals that have well developed hindlimbs (good for jumping/leaping), and smooth skin, often slippery (due to mucous glands that keep it moist). But there are many families of Anurans that are known as frogs, including: completely aquatic forms (such as the Pipidae); arboreal frogs and even marsupial frogs that have dorsal breeding pouches (Hylidae); gliding frogs (Rhacophoridae), and the well known "common" frogs included in Ranidae and Leptodactylidae. These animals may have special venom glands in different body parts, well developed interdigital membranes, adhesive toes, skin modifications, some have teeth, some don't... in a word, they're too diverse to be described in one paragraph. However, all are commonly called "frogs"!
738109
trees dont breathe as such during the winter months, they go into a sort of no growth regime. That is why they have defined growth rings. They start 'breathing' carbon dioxide again in spring when the new growth cycle starts up again
7930
Toads and frogs are BOTH amphibians.  Frogs have more permeable skin so lose more water through their skin and need a wetter environment.  Toads have dryer, wartier skin and are generally darker in color. Frogs lay eggs in clusters on water, toads lay eggs in strings. Frogs jump farther and have longer legs, toads hop. Frogs have tiny teeth, toads do not have teeth.
197081
am·phib·i·an\nn. \nA cold-blooded, smooth-skinned vertebrate of the class Amphibia, such as a frog or salamander, that characteristically hatches as an aquatic larva with gills. The larva then transforms into an adult having air-breathing lungs. \nAn animal capable of living both on land and in water. \nAn aircraft that can take off and land on either land or water. \nA tracked or wheeled vehicle that can operate both on land and in water.
468432
they have sex and then lay eggs which are called spawn. the larvae or tadpoles emerge and metamorphose into frogs (they grow legs).\n\nthe tadpoles are totally aquatic and have gills, which are lost as metamorphosis progresses. in salamanders the larval stage is called a axylotle and can remain in the larval stage for many yaers until a hormonal change in the water stars the change in development, this is a tactic enebling the salamnder to wait until the optimum time to reproduce, and cut out the chance of progressing to adulthood with no mates around to fertilize.
752106
Very well written. A few edits in [brackets] with explanations in (parenthesis).  English is HARD.\n\n\nAfter hatching, the tadpole will eat the [remaining] yolk (awkward) (no comma for subordinate clause) which is in their gut. [The tadpole] (pronoun-antecedent rules)  only had gills, a mouth and a tail when it first came out so it is very dangerous for them. If they [weren't] (subjunctive case for a conditional statement-tough one) careful, they [would] (matches the case) get eaten in no time[.]  (New clause) I’m so glad I’m not a frog; at least I don’t have to worry about this kind of problem! Then 7-10 days after hatching, the tadpoles can swim around[,] (separating independent clauses) and then they will not eat yolk anymore[;] (independent clause) they will find algae to eat. About 4 weeks later, the gills will start getting grown over by skin, and soon they will disappear! Wow! That really is fast! At [that] (article rules) time, tadpoles will get teeth, which can help them (no need to to leave "to chew" in the infinitive) chew and digest better. Few days after that, the tadpoles will interact and be friends with each other, isn’t that great?
687526
The trachea in reptiles is similar to that of higher vertebrates, with well-developed hyaline rings.  However, there is no mucociliary transport mechanism to aid the removal of foreign substances from the respiratory tract.  Furthermore, the absence of a diaphragm prevents the animal from coughing. \n\nThe lungs are similar to the avian-type system with a series of reticulated open-ended sacs and many capillaries in close proximity.  The cranial part of the reptile lung is the gaseous exchange portion, while the caudal part functions as an air sac.  The latter may act as a reserve of air during periods of apnoea. \n\nAlveolar macrophages are present in the reptilian lung, but may display poor bacterial removal if the animal is being kept below its optimal temperature. \n\nIn snakes, the right lung is larger than the left, and generally stretches from the heart to the kidney.  It may extend even further down to the cloaca in some aquatic snakes.  Some snakes have a tracheal lung on the dorsal aspect of the trachea, which enables the snake to breathe when the main lung is compressed by swallowed prey.
207219
They breathe air because as mammals, they have lungs. That's a constraint imposed by their evolutionary history; no mammal has "re-evolved" gills or other respiratory surfaces.\n \nOn the other hand, living in salt water has allowed them to develop huge bodies with little skeletal support. On land, where gravity is not counteracted by buoyancy, the sheer pressure exerted by the weight of their own bodies makes their bodies collapse. In addition, their skin dehydrates rapidly when exposed to the air. Thus, adaptation to a given environment always constrains survival in different environments. Evolutionary paths are like that.
603330
A dead body, after about 24 hours will normally afloat. Because human tissues started to decompose and microorganisms that are human's normal flora(pathogens living within the body) will start to create/form gas. They are commonly classified as gas-forming organisms. When they have form enough gases within the body to bring the body to the water surface, the body floats on the water.\n\nWe have to remember, that thru the process of mitosis, each single organism divides into two every fifteen minutes or sooner due to some mutation. Granting that we'll start counting them in millions, just imagine how much they will be in 24hours.
313612
They hatch from eggs. At first they are little larvae (squiggly white wormy things), then they pupate, metamorphose, and emerge as flies.
1041403
Spirogyra does not breathe per say.  It respires, which is an energy conversion process that takes place in the cytoplasm and mitochondria of its cells.  It also takes in oxygen from its surroundings through the process of diffusion.  Since it is a photosynthtic organism it also takes in carbon dioxide and water to form its own food.   So It also receives oxygen from the water that is destroyed as it is used in the photosynthetic process.
242069
You could have found good answers to this either in your textbook or by a little web searching. \nOh, well...\nThe eggs of frogs have little vitellum, i.e, they're oligolecithal. This means that the entire first cell (zygote) will cleave to originate the individual. It undergoes the usual phases: blastula, gastrula and neurula. \nSee more at the links:\nhttp://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/FrogEmbryology.html\nhttp://www.uoguelph.ca/zoology/devobio/dbindex.htm\nhttp://embryology.med.unsw.edu.au/OtherEmb/frog1.htm#Frog%20Life%20Cycle
304122
As little as it has been studied, the life cycle appears to be similar to other deep sea fish- Eggs are laid in shallow mud on the seafloor, they hatch little viper fish, that then grow to as much a 2 feet.  I dont know of anything indicating they go through a significant metamorphosis.
642095
The common wood frog freezes solid every winter and then, come spring, defrosts and mates. \n\nFrogs that survive freezing excite our imagination with visions of immortality. Underlining this excitement is the unexpected: our experience tells us that freezing kills. We've all read news stories of people who have lost fingers or toes to extreme cold, or even their lives. Thus, a whole animal that can survive freezing comes as a shock. Yet during the past two decades we have also read or even experienced the successes of in vitro fertilization, which involves the routine storage of sperm and embryos in a frozen state at cryogenic temperatures (-40°F or lower). So why is the survival of a frozen frog at 26°F surprising? \n\nThoroughly confused? You should be. Freezing has a yin-yang effect on biological materials—it can both preserve and destroy tissue. This paradoxical nature has led to two different fields of science and medicine built around freezing: cryopreservation and cryosurgery.\n\nSurviving the deep freeze\nLife is a complex set of electrochemical reactions. The rate at which chemical reactions take place depends on temperature, and usually the lower the temperature the lower the rate. At absolute zero Kelvin (-460°F), the rate is zero. Therefore, lowering the temperature of biological materials such as cells, organs, or entire organisms to absolute zero causes life to stop indefinitely. If a person or his or her body parts could survive the excursion to absolute zero and back, scientists and physicians could theoretically use such freezing as a vehicle to transport that person or parts to any point in the future. \n\nBecause we humans are mostly water, however, any journey into the supercool is physically traumatic. At about 31°F, the water in our bodies begins to freeze. It starts at this temperature (rather than 32°F) because biological water is in the form of a solution, mainly of ions or charged atoms. The survival of any cells during freezing depends at minimum on the rate the temperature changes. For most organisms, even the slowest cooling results in an assault on their cells that is just too great.\n\nResulting cell damage is related to the dissolved substances or solutes in biological water, to the cell membrane properties, and to the fact that ice has a very tight crystallographic structure and cannot contain solutes. When biological materials freeze, the solution between cells usually freezes first. Solutes found in the original solution are ejected and concentrated in the unfrozen space between the ice crystals. Cells usually remain unfrozen though supercooled.\n\nIn order to balance out the resulting difference in potential energy between the inside and outside of the cell, water leaves the cell through the cell membrane. Inside the cell, this loss of water causes an increase in the ionic concentration and leads to chemical damage. Interestingly, ions, not ice crystals, trigger cell injury during freezing. Theoretically, an infinitely fast rate to absolute zero would eliminate this harm. This is not possible, of course, and at higher cooling rates the supercooling of water in cells causes ice to form within those cells, which also brings about damage.\n\nNatural antifreezes\nCells in freeze-tolerant wood frogs experience the same mechanism of freezing injury as any other creatures' cells. The frogs freeze very slowly to a temperature often several degrees below freezing. This should destroy the frog's cells, yet those cells and the frog as a whole survive. How? A primary mechanism is through the production of glucose and its incorporation in the frog's cell. By lowering the amount of water that leaves the cell during freezing, the glucose offers protection against the rise in ionic concentration and excessive cell shrinkage, thereby reducing chemical harm.\n\nWhile the wood frog spent millions of years perfecting the use of such chemicals, scientists in the field of cryobiology disco
109880
18 days. On the 18th day the frog is at 17 feet. It then jumps up 3 feet.