el huevo amniótico de reptiles y aves está rodeado por una cáscara externa resistente que protege al huevo de los depredadores, patógenos, daños y secado.
punctuated equilibrium is a theory that describe the process of evolution based on different factors such as: fossil records and the history of the species, the sequence of the appearance of the specie from first to latter.
according to this theory, species did not originate at a defined rate, but it was irregular. according to it, they originated rapidly in start, in such as way that paleontologists were able to trace back their origin ancestors. this is called punctuation.
secondly, the fact that organisms which were the product of mutations remained unchanged for a long period of geological time shows stasis or equilibrium.
this theory shows that the process of this punctuation followed by stasis in the regulation of morphology as well as physiology of organisms. however, when this equilibrium was broken, it lead to the initiation of the continuous process of evolution.
this theory therefore seems very difficult from darwin's theory of natural selection which focuses on a continuous and regular process of natural selection that causes the process of speciation to happen. based on these facts, punctuated equilibrium is the right option,
hope it !
the answers are 1 and 3.
carbon cycle refers to an array of procedures by which the compounds of carbon are interconverted in the environment, comprising the inclusion of carbon dioxide into living tissue by the process of photosynthesis and then getting back into the atmosphere via respiration, the burning of fossil fuels, and the decomposition of dead organisms.
the following are the steps that illustrate how the carbon cycle functions:
1. carbon enters the atmosphere as carbon dioxide from combustion and respiration.
2. the absorption of carbon dioxide takes place by the producers to manufacture glucose in photosynthesis.
3. the animals feed on the plant passing the carbon components through the food chain. the majority of the consumed carbon is exhaled in the form of co2, which was produced at the time of aerobic respiration. the plants and animals die eventually.
4. the dead plants and animals get dissociated by the dead organisms and return the carbon present in their bodies back to the atmosphere as co2 by the process of respiration. in certain occasions, the dead plant and animals get converted into fossil fuel, which is available in future for combustion.