Hurricane Katrina was a density-dependent factor because this disaster affected everyone in the area. It did not selectively have an effect like
Around 4.1 billion years ago the first single celled organism appeared
<span> RNA was thought of as little more than a messenger between DNA and proteins, carrying instructions as messenger RNA (mRNA) to build proteins. However, RNA can do far more. It can drive chemical reactions, like proteins, and carries genetic information, like DNA. And because RNA can do both these jobs, most scientists think life as we know it began in an RNA world, without DNA and proteins.</span>
Arteries: any of the muscular-walled tubes forming part of the circulation system by which blood (mainly that which has been oxygenated) is conveyed from the heart to all parts of the body.
Capillaries: any of the fine branching blood vessels that form a network between the arterioles and venules.
Veins: any of the tubes forming part of the blood circulation system of the body, carrying in most cases oxygen-depleted blood toward the heart.
They are all similar because not only are they all connected to the heart, but they transfer blood and nutrients all around the body. They are different by where they are located and how effective their function is.
<span>c. numbers of neutrons.</span><span>
Isotopes are atoms of the same element with the same number of protons and same number of electrons but with <span>different number of neutrons. They differ in the number of neutrons that is why they also differ in mass numbers. Since they have the same number of protons, they have the same atomic number.
For instance, when the nucleus of the isotope with a 68.926 amu, there are 30 protons and 39 neutrons in the nucleus. The best example for this is Zn (zinc-69 isotope) and Ga (gallium-69 isotope) which has 68.926 amu and 68.925 amu respectively. </span></span>
