Genetic drift is the process where there are random fluctuations in the gene frequencies within a population. which of these populations would most likely experience genetic drift? a) the world's population of humans b) a small population of flowers in the amazon rain forest c) a population of bacteria experiencing exponential growth d) a large population of pine trees in the northern coniferous forest

How does the release of trapped gases in magma cause a volcano to erupt? a. they push the magma up the pipe and then are reabsorbed into the magma chamber. b. they cause the magma to change chemically into lava. c. the gases form vents that allow the magma to flow out. d. the gases rush out and carry the magma with them.

You have 2 plants of the same type and same size, same amount of leaves. one of them is put inside the house and the other one is put in the balcony. you water them saturday, one plant with 200 ml and the other with 400 ml of water. which one of your plants need less water? explain.

Experiments in environmental toxicology can sometimes be manipulative experiments in which the researcher actively chooses and manipulates the independent variable. in hunt's study, for example, dosages of bpa were manipulated and the effects were measured. in manipulative studies, the researcher controls all the other variables in the experiment, so any health effects observed in the test subjects can be attributed to differences in the independent variable. in other cases, researchers use natural experiments in which the dependent variable (typically a measure of organism health) is measured under differing contexts that are not manipulated. say, for example, that an accidental chemical spill contaminates five ponds. to determine the possible effects of the toxic chemical on frogs, a researcher could compare the hatching rate of frog eggs laid in those five ponds to the hatching rate of eggs laid in five uncontaminated ponds nearby. this would be an example of a natural experiment because concentrations of the toxic chemical in the ponds were not controlled by the experimenter, but rather resulted from the chemical spill. drag type of experiment on the left to the example of experiment on the right. blood concentrations of bpa in college students are compared to their recent manipulative consumption of canned food items 2. the feeding behavior of fish in streams that receive acidic runoff from strip mines is compared to the feeding behavior of fish in unaffected streams. the deformity rate in baby birds from nests in pesticide-sprayed fields is compared to the deformity rate in birds from nests in unsprayed fields 4 tumor development is compared in mice exposed to five dosages of a known carcinogen in the laboratory foraging activity levels are compared in tadpoles exposed to four concentrations of toxic metals in the laboratory. growth of corn plants is compared in field plots sprayed with three different dosage: s of weed killer 7 bpa concentrations in the urine of people with diabetes are compared to bpa concentrations in the urine of people without diabetes - natural; manipulative