A carrot would be an example of a system. The apical meristem and new growth in the roots are protected by the . Stems of contain a ring of vascular tissue, which includes the xylem and phloem. Stems thicken to support plants growing taller during growth. regulate the exchange of gases in the leaves and help maintain homeostasis. The leaves are often broad and flat because they are the main site of in a plant. The force that allows water molecules to stick to other water molecules is called . The process by which plants release water into the air as vapor, while pulling more water upward into the leaves is called . Respond to the following based on your reading. Explain, in your own words, the role of cohesion and adhesion in plant transpiration. What are several adaptations that leaves have undergone? Why do leaves have adaptations in different parts of the world? Choose three nutrients and explain how a plant may look if it has a deficiency in those nutrients.

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

What happens during the experiment stage of the scientific method

Blank is a rock with a find dark texture that makes up the oceanic crust