Andrew Polyak

I might be reiterating previous responses, but there are usually speciation events that take place, that prevents gene flow between two groups of organisms. For example: A physical barrier could appear between groups of individuals Selective mating: such as a blue fly only wanting to mate with other blue flies. Even though a yellow fly can still mate with a blue fly, it chooses not to! etc. This lack of gene flow could eventually lead to speciation.

This might be rather a simple response, and please forgive me for doing so. In my eyes, whatever the odds, it only had to happen once.

This question seems more like a question of evolution. A bacteria doesn't just decide, "hey, I'm going to be hydromycin resistant today!". The change is actually quite by chance. These chance mutations start evolution over many generations, and can be passed to another through chance methods like homologus recombination. These resistant bacteria can now be selected for!

The heats of combustion (to CO2 and H2O) of some C5 compounds are given below. Z-2-pentene –3369 kJ/mol E-2-pentene –3365 kJ/mol 1-pentene –3376 kJ/mol pentane–3536 kJ/mol The heat of formation of CO2 is –393 kJ/mol and that of H2O is –285 kJ/mol. What is the heat of hydrogenation of 1-pentene (in kJ/mol)? There are three questions on my OCHEM practice exam like this, and I can't understand any of them. I understand everything else, but I want the extra 50 points. I know how to calculate delta h using BDE, but that's where my knowledge stops.

Hey All, I have quite a few questions about drawing molecular orbitals. How does one know what endergy differences to draw? Are they given? I'm in organic chemistry 1, and I'm having a really bad time. Any insight would be appreciated!

I'm pretty sure that during telophase, the chromosomes that broke apart from the chromatids come to the poles make it to their ends, and the spindle fibers they move along disappear. Is this what you're asking? I'm sorry the HTML kinda jumbled up your question a bit.

Greetings, my name is Andrew and I'm a student at Penn State currently studying Biology. I work in the lab at a hospital Bethlehem, PA, and my ultimate goal is to become an oncologist. I'm a bit of a computer nerd too, I specialize in C++, JAVA and Visual Basic, however my passion is medicine.

I'd imagine the urine would mess with the milliosmolarity in the urine, but that probrably wouldn't be affected after ingesting absurd amounts of urine, haha. Bear Grylls doesn't seem to have a problem with it.