There are a number of amino acids that have formed under certain environmental conditions if the required elements are present and the energy conditions ar compatible with chemical assembly. These conditions have also allegedly formed amino acids on meteors, asteroids and comets.
But, amino acids are a very minor component of more complex biochemical assemblies required for life. Pentose sugars are also required, which form under different environmental conditions than amino acids. More importantly, only left-handed homochiral amino acids and right-handed homochiral sugars can form functioning biochemical assemblies that are viable in an organism. But, natural conditions, like hydrothermal vents only produce racemic versions of sugars and acids, meaning they are always approx. 50% left and right handed. This is fatal to forming viable biochemical assemblies.
Further, it is not possible for all of the 20+ homochiral amino acids needed for a living organism to form naturally. The only ones found have been the simpler amino acids. Also, the 4 critical nucleotide amino acids, C, G, A, T, do not form naturally, are not homochiral, nor in the right proportions.
The geo/hydrothermal vent conjecture is nonsensical. These are open systems, susceptible to currents, mineral contamination, salinity, ph, and temperature, making them a totally unacceptable environment for the precise and exact placement of elements to assemble to form life.
I believe the correct answer is C. Nektons include bony fish and squid.
Half life formula
The number of unstable nuclei remaining after time t can be determined according to this equation:
N(t) = N(0) * 0.5^(t/T)
where:
N(t) is the remaining quantity of a substance after time t has elapsed.
N(0) is the initial quantity of this substance.
T is the half-life.
It is also possible to determine the remaining quantity of a substance using a few other parameters:
N(t) = N(0) * e^(-t/τ)
N(t) = N(0) * e^(-λt)
τ is the mean lifetime - the average amount of time a nucleus remains intact.
λ is the decay constant (rate of decay).
All three of the parameters characterizing a substance's radioactivity are related in the following way:
T = ln(2)/λ = ln(2)*τ
How to calculate the half life
Determine the initial amount of a substance. For example, N(0) = 2.5 kg.
Determine the final amount of a substance - for instance, N(t) = 2.1 kg.
Measure how long it took for that amount of material to decay. In our experiment, we observed that it took 5 minutes.
Input these values into our half life calculator. It will compute a result for you instantaneously - in this case, the half life is equal to 19.88 minutes.
If you are not certain that our calculator returned the correct result, you can always check it using the half life formula.
Answer:
there is nothing under the question.
Explanation:
Skeletal mass increases dramatically during childhood and adolescence, and decreases dramatically at the beginning of the fourth decade of life and decreases with age, with an exception of the skull.
Hope this helps! Have a BLESSED day! :-)
