The dissolved oxygen concentrations were consistently higher in the lake with zooplankton and trout even though the lakes and the phosphorus levels were identical. Why could having consumers as well as producers in the lake change the amount of dissolved oxygen in the lake

the answer is tropical areas. the tropical areas obtain more

radiant energy from the sun than they lose to space through terrestrial

radiation, and vice versa for polar areas. earth has an energy remaining in the

tropics and an energy scarcity for the polar areas.

explanation:

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."

igneous rocks which formed by the crystallization of magma at the surface of the earth called extrusive rocks. they are characterized by fine-grained textures because the rapid cooling at or near the surface did not provide enough time for large crystals to grow.

the answer is c.mitochondria. glad to .