Abiologist wants to test some lake water for the presence of nitrates. he has a sensor that detects even the tiniest amount of nitrates by turning an internal light from green to red. a) what will be his positive control? (specific). b) what will be his negative control? (specific). c) why does he need o include these controls?

The diagram shows the layers of earth. convection currents in which region influence the movement of tectonic plates

Matthew decided he wanted to hike up mount everest. on his way to the top, it began to snow and the temperature dropped to -10°f. matthew forgot to wear a heavy jacket so his body began to shiver beyond control. in this case, matthew's body shivering is the to a drop in temperature. * 0 points reflex stimuli responce environmental facto

Punnett squares are used to show possible combinations of alleles or to predict the probability of a trait occurring in offspring. an incomplete dominance cross is performed between a bird that is homozygous for red feathers and a bird that is homozygous for blue feathers. purple offspring result. then, two of the purple offspring are crossed. according to the punnett square for this cross, how many of the offspring from the second cross will have a feather color that results from incomplete dominance? 1 in 4 2 in 4 3 in 4 4 in 4