The red pigment in erythrocytes is whitch transports oxygen.
a. hemoglobin
b. phycoerythrin
c. carotenoid
d. chlorophyll

Use the drop-down menu to complete the statement. an electron in the first energy level of the electron cloud has an electron in the third energy level.a. a lower energy thanb. a higher energy thanc. the same energy as

Some technological solutions to problems like global warming meet the specific needs and situations of local communities. an example from india involves converting the solid waste from cattle into clean-burning fuel for cooking. this reduces the amount of greenhouse gases, specifically methane and carbon dioxide, released into the environment from wood fires. when evaluating the feasibility of implementing this solution, computer models are used to weigh costs against benefits. what factor is least likely to impact the decision on adopting this technology?

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