Processes in the human body are often complex and can be difficult to represent with a physical model. Evaluate the model that Sammi designed by thinking about how her model compares to the actual interaction of the digestive and circulatory systems. Then, sort the statements according to whether they are strengths or weaknesses of her model. Not all statements will be used. 1. Cardboard and the tissue of the digestive tract have different properties.
2. Only one system is included in the model.
3. All of the major organs involved in digestion are included.
4. The capillaries are more complex than one, large plastic tube.
5. The major organs responsible for circulating blood are included.
6. The process of nutrient absorption is depicted in a visual way.
7.The corrugated cardboard shows how villi increase the surface area of the digestive tract.

Asolution of an enzyme and a substrate was placed in a water bath and the temperature of the reaction was raised gradually. the graph shown was plotted at the end of the experiment. what can be concluded from the graph? a) temperature has no effect on the activity of the enzyme. b) the effect of temperature on the enzyme is unpredictable. c) the enzyme shows increased activity up to a certain temperature. d) the activity of the enzyme is inversely proportional to the temperature.

The kidney filters potentially toxic substances in the blood, and thus “clears” the blood of those substances. this clearance function is dependent upon and proportional to the diffusion gradient of the substance across filtering capillaries, i.e. if the concentration of the substance is doubled, twice as much will be cleared from each ml of blood that is filtered. suppose that the body produces a constant amount of a substance x per unit of time. the kidneys eliminate substance x at a rate directly proportional to the concentration of the substance and the volume of blood cleared each minute (c): elimination = c × [x], where [x] is the steady-state concentration of substance x. imagine an individual with an initial concentration of x equal to [x]0 who develops kidney disease. her baseline clearance c0 drops to one half of the original (½c0). what is the new steady state concentration of x? (for simplicity, assume that substance x is 100% filtered by the kidney).

Which soil would most likely be found in the arctic? andisols gelisols histosols spodosols