Answer:Chromatography is actually a way of separating out a mixture of chemicals, which are in liquid or gas form, by letting them flow slowly past another substance, which is either a solid or a liquid. It consist of a stationary phase and a mobile phase.
Explanation: All chromatographic systems rely on the fact that a substance placed in contact with two unmixable phases, one movable phase and one stationary phase, will equilibrate between them. A selectivity (or separation) factor (α) is used to 'chemically' distinguish between sample components. It is usually measured as a ratio of the retention (capacity) factors (k) of the two peaks in question and can be visualized as the distance between the apices of the two peaks. reproducible fraction will partition into each phase, depending on the relative affinity of the substance for each phase. A substance which has affinity for the moving or mobile phase will be moved rapidly through the system. A material which has a stronger affinity for the stationary phase, on the other hand, will spend more time immobilized in that phase, and will take a longer time to pass through the system. Therefore, it will be separated from the first substance. By definition, chromatography is a separation technique in which a sample is equilibrated between a mobile and a stationary phase. A theoritical plate or tray is used to produces the best possible difference between the liquid and vapour phases in equilibrium with it
Chromatographic separations are best done with a small amount of analyte (substance to be separated during analysis), which keeps either phase from becoming saturated with analyte, so that the concentrations in the two phases are directly proportional. Overloading the column with sample causes one of the phases to become saturated, leading to a loss of column efficiency, and poorly shaped peak profiles.
The retention volume in chromatographic separation (Vr) is the volume of the mobile phase required to carry the solute through the column to elution, is related to the column flow (Fc) and the retention time (tr). Likewise, the volume of the mobile phase(Vm), is related to the flow and the time the void volume takes to pass through the column.
Band broadening using the kinetic model is a phenomenon that reduces the efficiency of the separation being carried out, leading to poor resolution and chromatographic performance. This is problematical in terms of both the quality of the separation obtained and the accuracy with which sample components can be quantified.The wider band results in a dilution effect that produces a decrease in peak height accompanied by a loss in sensitivity and resolution. The eddy dispersion, accounts for the source of band broadening related to any flow unevenness in the column.
Answer:
The tympanic membrane and stapes of the bullfrog can be driven by airborne sound over a wide frequency range, with a broad maximum in their velocity amplitudes between 0.4 and 2 kHz (Mason and Narins, 2002a).
It mainly depends on the population size and technologies in the environment (Human Interference falls into that) .
Here is your answer......
Explanation:
Monotremes are mammals that lay eggs. Monotremes are warm blooded with a fast metabolism. They have hairy bodies to keep warm.
Marsupials are mammals that give birth to live young. These mammals have a pouch where their young grow and develop. Marsupials are hairy, warm blooded, and produce milk. One of the biggest differences between marsupials and placental mammals is that marsupials give birth quite early and rely less on the nourishment of the placenta. Some examples of marsupials are kangaroo and opossums.
Placental mammals are mammals that give birth to fully developed live young. They differ from marsupials in that the baby spend more time being nourished in-utero by the placenta. These mammals are hairy and warm blooded as well. Some examples are mice, rats, and bats
Hope it helps.....
In asexual reproduction, reproductive organs aren't used but they're used.
advantage of sexual- A lot of genetic variation. since they have DNA of two parents. they can survive more and adapt more.
disadvantage of asexual- diversity is limited. Since the organism only gets the DNA of one parent, they wouldn't be able to really survive if something happened.They would easily be extinct.
Sorry I can't really cone up with better words but I hope you get the idea. it all comes down to natural selection really if you've learned about it. Hope it helped!!!
