<span>Noctilucent clouds (sometimes known as night clouds or mesopheric clouds) form in the mesosphere, a layer of the atmosphere located 47-59 miles above the Earth. </span>
Answer:
A substance that speeds up a chemical reaction—without being a reactant—is called a catalyst. The catalysts for biochemical reactions that happen in living organisms are called enzymes. Enzymes are usually proteins, though some ribonucleic acid (RNA) molecules act as enzymes too.
Explanation:
enzymes don't change their own reaction. That's because they don't affect the free energy of reactants or the products.
Rinderpest disease is caused by a virus that affects hoofed animals, including cattle and wildebeest. In the 1950s, a cattle vaccination program was implemented to eradicate the disease in the Serengeti, and this led to dramatic changes in the populations of wildebeest and other species. The figure shows the number of wildebeest in the Serengeti ecosystem (shaded circles, left y-axis) and the prevalence (i.e., percentage) of individuals infected by rinderpest disease (unshaded squares and triangles, right y-axis) from 1958 to 2003.
