Answer:
Chitin.
Explanation:
The structure that is not a component of wall of sponges is Chitin. Their body comprise of calcareous or siliceous spicules or protein spongin fibres. Choanocytes are the distinctive cells located in the interior body walls of sponges. Sponges are similar to other animals in many characteristics such as they are multicellular, heterotrophic, lack cell walls and produce sperm cells in order to produce offspring sexually and also different from animals due to lack of tissues and organs.
Answer:
Plants and animals assimilate carbon-14 from carbon dioxide throughout their life. When they die, they stop exchanging carbon with the biosphere and their carbon-14 content begins to decrease at a rate determined by the law of radioactive decay.
Radiocarbon dating is basically a method designed to measure residual radioactivity.
Explanation:
Carbon-14 is a weakly radioactive carbon isotope; It is also known as radiocarbon, and is an isotopic stopwatch.
Radiocarbon dating is only applicable to organic materials and some inorganic materials (not applicable to metals).
Proportional gas counting, liquid scintillation counting, and accelerator mass spectrometry are the three main methods of radiocarbon dating.
The radiocarbon, or carbon-14, is an isotope of the carbon element that is unstable and weakly radioactive. The stable isotopes are carbon-12 and carbon-13.
Carbon 14 is continuously formed in the upper atmosphere by the effect of cosmic ray neutrons on nitrogen-14 atoms, rapidly oxidizing in the air to form carbon dioxide and entering the global carbon cycle.
Accelerator mass spectrometry (AMS) is a modern method of radiocarbon dating that is considered the most efficient way to measure the radiocarbon content of a sample. In this method, the content of carbon-14 is measured directly in relation to carbon-12 and carbon-13 present. The method does not take into account beta particles, but the number of carbon atoms present in the sample and the proportion of the isotopes.
Carbondioxide, being a green house gas has the property of trapping the heat from the sunlight and thus increasing the temperature of the place. As more and more rain forests are cut down and burned, there is an increase in this green house gas in the atmosphere thus leading to a steady increase in the temperatures.
As we look at the graphs that are given, we can see that the graph C shows the steady increase in the temperature as the time passes. Hence option C is the right answer
Answer:
es la persona que ejecuta la accion esta omitida pero no hay duda de su existencia
Explanation:
Para ejecutar al sujeto en una oracion existen algunos indicios .La conjugacion del verbo, los pronombres,sujeto expreso en la oracion previa
POR EJEMPLO.
corremos todos los dias*sujeto táctil nosotros *
lo conoci hoy *sujeto táctil yo*.
