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.
Answer:
Explanation:
Muscle contraction is stimulated by the movement of an action potential moving along a nerve fiber to the muscles. This event follow some series of process before being stimulated.
1. The impulse arrives at the synapse and travels through the transverse tubules.
2. The muscle impulse reaches the sarcoplasmic reticulum and calcium is released.
3. Calcium floods the sarcoplasm and binds to troponin molecules leaving active sites.
4. Tropomyosin molecules bind to exposed active sites, linking actin and myosin.
5. Thin filaments are pulled over the thick filaments.
6. The muscle fiber shortens and contracts.
An operon is a stretch of DNA consisting of an operator, a promoter, and genes for a related set of proteins, usually making up an entire metabolic pathway.
operon is a functional unit of gene.
This cluster of gene transcribed together to give a messenger RNA which further give rises to protein.
operator in operon is the site where repressor binds.
promoter is where Mrna binds , where our genes are transcribed
structural genes, they code for the enzyme that are involved in this metabolic pathway.
Operons have an important role to play as they produce protein for the cell this serves them energy, the protein is produced only when energy is required.
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Answer:
Money is channeled through financial institutions such as banks.
Explanation:
The borrower may chose to use the funds to invest in a business venture and thus be becomes an investor. Money is channeled through financial institutions such as banks. A saver saving with a bank account seeks to keep the money in the bank as it earns him interest.