Valerie designed and conducted an experiment on pothos plants, which are common houseplants. her hypothesis is that the direction of light will affect the growth pattern of a pothos plant. to test the hypothesis, she sets up two test groups of pothos plants and observes them three weeks later. the table summarizes the test groups and observations. test group growth conditions observations 1 light source is only on the side of the plant stems and leaves are bent toward the light 2 light source comes from all directions stems and leaves are not bent what are the roles of the two test groups in this investigation?

The roles of two test groups in the investigating a phenomenon known as  positive phototropism. This phenomenon occurs in the plants that responds to external stimuli (light). In this experiment we can see that the pothos plant is having a positive response in both the cases :

1. When the light source is on one side the stems and leaves are bending towards the light source only on one side

2. On the other hand when the pothos plant is given lights from all the directions the growth of the plant takes place in all the directions equally hence it proves that the plant is showing positive responses in the directions where light is present  

hypoxemia refers to a below usual concentration of oxygen in the blood, mainly in the arteries. hypoxemia is an indication of an issue associated with circulation or breathing and may lead to various symptoms like shortness of breath.  

the condition is identified by determining the level of oxygen in the blood sample obtained from an artery. it can also be predicted by determining the oxygen saturation of the blood with the application of a pulse oximeter.  

the normal arterial oxygen is about 75 to 100 mm hg. the values underneath 60 mm hg is generally considered with the requirement for supplemental oxygen. the normal pulse oximeter readings generally range between 95 to 100 percent. the values under 90 percent are regarded as low.  

in the given case, the oxygen saturation is measured at 93 percent, hence, there is no need to administer oxygen, that is, one should withhold oxygen.